Unassociated Document


    
      

         

        FIRST
          AMENDED AND RESTATED

        SENIOR
          CREDIT AGREEMENT

         

        DATED
          AS OF MAY 24, 2007

         

        AMONG

         

        UNIT
          CORPORATION,

        SUPERIOR
          PIPELINE COMPANY, L.L.C.,

        UNIT
          DRILLING COMPANY,

        UNIT
          PETROLEUM COMPANY,

        and

        UNIT
          TEXAS DRILLING, L.L.C.,

         

        AS
          BORROWERS,

         

        THE
          LENDERS,

         

        BANK
          OF OKLAHOMA, NATIONAL ASSOCIATION,

        AS
          ADMINISTRATIVE AGENT FOR THE LENDERS,

        and
          as

        CO-ARRANGER

         

        BANK
          OF AMERICA, NATIONAL ASSOCIATION,

        CO-ARRANGER

         

        BMO
          CAPITAL MARKETS FINANCING, INC.,

        SYNDICATION
          AGENT

         

        and

         

        COMPASS
          BANK,

        DOCUMENTATION
          AGENT

         

        
          
            
              
                	
                      	 	 


              

               

            

            
            

          

          
            
            

            
            

          

          
            
            

            
            

          

        



        TABLE
          OF CONTENTS

         

         

        
          	Article I 
                  DEFINITIONS	
                   2

                
	    
                  1.1	 Defined
                  Terms 	
                   2

                
	    
                  1.2	 Exhibits
                  and Schedules; Additional Definitions 	
                   15

                
	    
                  1.3	 Reference
                  and Titles	
                   15

                
	
                      
                    1.4

                	 Accounting
                  Terms and Determinations 	
                   16

                
	    
                  1.5	 Calculations
                  and Determinations 	
                   16

                
	    
                  1.6	 Joint
                  Preparation; Construction of Indemnities and Releases 	
                   16

                
	 	 	 
	
                  Article
                    II  THE CREDITS 

                	
                   16

                
	     2.1	 Commitments	
                   16

                
	    
                  2.2	 Required
                  Payments; Termination 	
                   16

                
	    
                  2.3 	 Ratable
                  Loans 	
                   17

                
	    
                  2.4	 Types
                  of Advances 	
                   17

                
	    
                  2.5	 Facility
                  Fee; Initial Aggregate Commitment; Maximum Credit Amount; 	 
	 	 Commitment
                  Fee Rate 	
                   17

                
	    
                  2.6	 Borrowing
                  Base 	
                   17

                
	    
                  2.7	 Minimum
                  Amount of Each Advance 	
                   21

                
	    
                  2.8	 Principal
                  Payments 	
                   21

                
	    
                  2.9	 Method
                  of Selecting Loan Types and Interest Periods for New Advances 	
                   21

                
	    
                  2.10	 Conversion
                  and Continuation of Outstanding Advances 	
                   22

                
	    
                  2.11	 Changes
                  in Interest Rate 	
                   22

                
	 
                     2.12	 Rates
                  Applicable After Default 	
                   23

                
	    
                  2.13	 Method
                  of Payment 	
                   23

                
	    
                  2.14	 Evidence
                  of Indebtedness 	
                   24

                
	    
                  2.15	 Telephonic
                  Notices	
                   24

                
	     2.16	 Interest
                  Payment Dates 	
                   24

                
	    
                  2.17	 Notification
                  of Advances, Interest Rates, and LC Requests 	
                   25

                
	    
                  2.18	 Non-Receipt
                  of Funds by the Administrative Agent 	
                   25

                
	    
                  2.19	 Letters
                  of Credit 	
                   25

                
	    
                  2.20	 Additional
                  Agency Fees 	
                   29

                
	    
                  2.21	 Loan
                  Purposes 	
                   29

                
	 	 	 
	
                  Article
                    III  YIELD PROTECTION; TAXES 

                	
                   29

                
	    
                  3.1	 Yield
                  Protection 	
                   29

                
	    
                  3.2	 Changes
                  in Capital Adequacy Regulations 	
                   30

                
	    
                  3.3	 Taxes	
                   30

                
	    
                  3.4	 Availability
                  of Eurodollar Advances 	
                   31

                
	    
                  3.5	 Funding
                  Indemnification 	
                   32

                
	    
                  3.6	 Replacement
                  Lenders	
                   32

                
	    
                  3.7	 Extension
                  of Maturity Date 	
                   33

                
	 	 	 
	Article
                  IV CONDITIONS PRECEDENT	
                   35

                
	    
                  4.1	 Initial
                  Credit Extension 	
                   35

                


        

         

         

        
          
            i

          

          
            
            

            
            

          

          
            
            

          

        

         

        
          
            	    
                    4.2	 Each
                    Credit Extension	
                    36

                  
	    
                    	 	
                     

                  
	Article
                    V REPRESENTATIONS AND WARRANTIES	
                    37

                  
	    
                    5.1	 Existence
                    and Good Standing 	
                    37

                  
	    
                    5.2	 Authorization
                    and Validity 	
                     37

                  
	    
                    5.3	 No
                    Conflict; Government Consent 	
                     37

                  
	    
                    5.4	 Financial
                    Statements 	
                     38

                  
	    
                    5.5	 Material
                    Adverse Effect 	
                     38

                  
	    
                    5.6	 Taxes	
                     38

                  
	    
                    5.7	 Litigation
                    and Contingent Obligations 	
                     38

                  
	    
                    5.8	 Subsidiaries	
                     38

                  
	    
                    5.9	 ERISA 	
                     39

                  
	    
                    5.10	 Accuracy
                    of Information 	
                     39

                  
	    
                    5.11	 Margin
                    Stock 	
                     39

                  
	    
                    5.12	 Material
                    Agreements 	
                     39

                  
	    
                    5.13	 Compliance
                    With Laws 	
                     39

                  
	    
                    5.14	 Ownership
                    of Properties 	
                     39

                  
	    
                    5.15	 Plan
                    Assets; Prohibited Transactions 	
                     40

                  
	    
                    5.16	 Environmental
                    Matters 	
                     40

                  
	    
                    5.17	 Names
                    and Places of Business 	
                     41

                  
	    
                    5.18	 Possession
                    of Franchises, Licenses 	
                    41

                  
	  
                      5.19	 Rate
                    Management Transactions 	
                     42

                  
	    
                    5.20	 Insurance	
                     42

                  
	    
                    5.21	 No
                    Default 	
                     42

                  
	 	 	 
	Article
                    VI  AFFIRMATIVE COVENANTS	
                     42

                  
	    
                    6.1	 Reports	
                     42

                  
	    
                    6.2	 Use
                    of Proceeds 	
                     44

                  
	    
                    6.3	 Notice
                    of Default 	
                     44

                  
	    
                    6.4	 Conduct
                    of Business 	
                     44

                  
	    
                    6.5	 Taxes 	
                     44

                  
	    
                    6.6	 Insurance	
                     45

                  
	    
                    6.7	 Compliance
                    With Laws 	
                     45

                  
	    
                    6.8	 Maintenance
                    of Properties 	
                     45

                  
	    
                    6.9	 Inspection	
                     45

                  
	    
                    6.10	 Deposit
                    Accounts/Setoff 	
                     45

                  
	    
                    6.11	 Ratable
                    Payments 	
                     46

                  
	    
                    6.12	 Environmental
                    Indemnities 	
                     46

                  
	 	 	 
	Article
                    VII  NEGATIVE COVENANTS 	
                     47

                  
	    
                    7.1	 Dividends	
                     47

                  
	    
                    7.2 	 Indebtedness	
                     48

                  
	    
                    7.3	 Limitation
                    on Fundamental Changes 	
                     49

                  
	    
                    7.4	 Sale
                    of Assets 	
                     49

                  
	    
                    7.5	 Investments
                    and Acquisitions 	
                     50

                  
	    
                    7.6	 Liens	
                     51

                  
	    
                    7.7	 Affiliates	
                     52

                  


          

        

         

        
          
            ii

          

          
            
            

            
            

          

          
            
            

          

        

         

        
           

          
            
              	    
                      7.8	 Sale
                      and Leaseback Transactions and other Off-Balance Sheet Liabilities 	
                      52

                    
	    
                      7.9	 Contingent
                      Obligations 	
                       52

                    
	    
                      7.10	 Financial
                      Contracts 	
                       53

                    
	    
                      7.11	 Letters
                      of Credit 	
                       54

                    
	     7.12	 Prohibited
                      Contracts 	
                       54

                    
	    
                      7.13	 Negative
                      Pledge 	
                       54

                    
	 	 	 
	
                      Article
                        VIII  FINANCIAL COVENANTS

                    	
                       54

                    
	    
                      8.1	 Current
                      Ratio 	
                       54

                    
	    
                      8.2	 Leverage
                      Ratio 	
                       54

                    
	    
                      8.3	 Minimum
                      Consolidated Net Worth 	
                       54

                    
	 	 	 
	
                      Article
                        IX  GUARANTEES

                    	
                       54

                    
	    
                      9.1	 Guarantees	
                       54

                    
	    
                      9.2	 Negative
                      Pledge/Production Proceeds 	
                       55

                    
	 	 	 
	Article
                      X  EVENTS OF DEFAULTS	
                       55

                    
	 	 	 
	Article
                      XI ACCELERATION, WAIVERS, AMENDMENTS AND REMEDIES	
                       57

                    
	    
                      11.1	 Acceleration	
                       57

                    
	    
                      11.2	 Amendments	
                       58

                    
	    
                      11.3	 Preservation
                      of Rights 	
                       58

                    
	 
                      	 	
                       

                    
	
                      Article
                        XII  GENERAL PROVISIONS

                    	
                       59

                    
	    
                      12.1	 Survival
                      of Agreements 	
                       59

                    
	    
                      12.2	 Governmental
                      Regulation 	
                       59

                    
	    
                      12.3	 Headings	
                       59

                    
	    
                      12.4	 Entire
                      Agreement 	
                       59

                    
	    
                      12.5	 Several
                      Obligations; Benefits of this Agreement 	
                       59

                    
	    
                      12.6	 Expenses;
                      Indemnification 	
                       59

                    
	    
                      12.7	 Severability
                      of Provisions 	
                       60

                    
	    
                      12.8	 Nonliability
                      of Lenders 	
                       60

                    
	    
                      12.9	 Confidentiality	
                       61

                    
	    
                      12.10	 Disclosure	
                       61

                    
	    
                      12.11	 Place
                      of Payment 	
                       61

                    
	    
                      12.12	 Interest	
                       61

                    
	    
                      12.13	 Automatic
                      Debit of Borrowers’ Operating Account 	
                       62

                    
	    
                      12.14	 Exceptions
                      to Covenants 	
                       62

                    
	    
                      12.15	 Conflict
                      with Other Loan Documents 	
                       62

                    
	    
                      12.16	 Lost
                      Documents 	
                       63

                    
	 	 	 
	
                      Article
                        XIII THE ADMINISTRATIVE AGENT 

                    	
                       63

                    
	    
                      13.1	 Appointment;
                      Nature of Relationship 	
                       63

                    
	    
                      13.2	 Powers	
                       63

                    
	    
                      13.3	 General
                      Immunity 	
                       63

                    
	    
                      13.4	 No
                      Responsibility for Loans, Recitals 	
                       64

                    
	    
                      13.5	 Action
                      on Instructions of Lenders 	
                       64

                    


            

          

        

         

         

        
          
            iii

          

          
            
            

            
            

          

          
            
            

          

        

         

        
           

          
            
              	    
                      13.6	 Employment
                      of Administrative Agents; Counsel; Reliance 	
                      64

                    
	    
                      13.7	 Administrative
                      Agent's Reimbursement and Indemnification 	
                       65

                    
	    
                      13.8	 Notice
                      of Default 	
                       65

                    
	    
                      13.9	 Rights
                      as a Lender 	
                       65

                    
	    
                      13.10	 Lender
                      Credit Decision 	
                       65

                    
	    
                      13.11	 Successor
                      Administrative Agent 	
                      66

                    
	    
                      13.12	 Syndication
                      Agent 	
                       66

                    
	    
                      13.13	 Delegation
                      to Affiliates 	
                       66

                    
	 	 	 
	
                      Article
                        XIV BENEFIT OF AGREEMENT; ASSIGNMENTS;
                        PARTICIPATIONS

                    	
                       67

                    
	    
                      14.1	 Successors
                      and Assigns 	
                       67

                    
	    
                      14.2	 Participations
                      	
                       67

                    
	    
                      14.3	 Assignments
                      	
                       68

                    
	    
                      14.4	 Dissemination
                      of Information 	
                       69

                    
	     14.5	 Tax
                      Treatment 	
                       70

                    
	    
                      14.6	 Procedure
                      for Increases and Addition of New Lenders 	
                       70

                    
	 	 	 
	Article
                      XV  NOTICES/CONSENTS	
                       70

                    
	    
                      15.1	 Notices	
                       70

                    
	    
                      15.2	 Change
                      of Address	
                       70

                    
	    
                      15.3	 Consent
                      to Amendments	
                       70

                    
	    
                      15.4	 USA
                      PATRIOT Act Notice 	
                       71

                    
	 	 	 
	
                      Article
                        XVI  COUNTERPARTS

                    	
                       71

                    
	 	 	 
	Article
                      XVII CHOICE OF LAW; CONSENT TO JURISDICTION; WAIVER OF JURY
                      	 
	TRIAL	
                       71

                    
	    
                      17.1	 CHOICE
                      OF LAW 	
                       71

                    
	    
                      17.2	 CONSENT
                      TO JURISDICTION 	
                       72

                    
	    
                      17.3	 NO
                      ORAL AGREEMENTS 	
                       72

                    
	    
                      17.4	 EXCULPATION
                      PROVISIONS 	
                       72

                    
	    
                      17.5	 WAIVER
                      OF JURY TRIAL, PUNITIVE DAMAGES 	
                       73

                    


            

          

        

         

         

        
          
            iv

          

          
            
            

            
            

          

          
            
            

          

        


        Exhibits

         

        Exhibit
          A - Form
          of
          Promissory Note

        Exhibit
          B - Compliance
          Certificate

        Exhibit
          C - Form
          of
          Assignment

        Exhibit
          D - Form
          of
          Commitment Increase/Additional Lender

        Exhibit
          E - Form
          of
          Subsidiary Guaranty

         

        Schedules

         

        Schedule
          1 - Pricing
          Schedule

        Schedule
          2 - Lenders
          Schedule

        Schedule
          3 - Disclosure
          Schedule

        Schedule
          4 - Environmental
          Matters

        Schedule
          5 - Rate
          Management Transactions

        Schedule
          6 - Excluded
          Accounts

        Schedule
          7  - Contingent
          Obligations

         

        


        
          
            v

          

          
            
            

            
            

          

          
            
            

          

        

         


        FIRST
          AMENDED AND RESTATED

        SENIOR
          CREDIT AGREEMENT

         

        THIS
          FIRST AMENDED AND RESTATED SENIOR CREDIT AGREEMENT, dated effective as
          of May
          24, 2007 ("Agreement"), is entered into among UNIT CORPORATION, a Delaware
          corporation ("Unit"), SUPERIOR PIPELINE COMPANY, L.L.C., an Oklahoma limited
          liability company, UNIT DRILLING COMPANY, an Oklahoma corporation, UNIT
          PETROLEUM COMPANY, an Oklahoma corporation, and UNIT TEXAS DRILLING, L.L.C.,
          an
          Oklahoma limited liability company, each with its principal place of business
          at
          7130 South Lewis, Suite 100, Tulsa, Oklahoma 74136 (collectively the
          "Borrowers") and BANK OF OKLAHOMA, NATIONAL ASSOCIATION ("BOk"), as co-arranger,
          BANK OF AMERICA, N.A. ("B of A"), as co-arranger, BMO CAPITAL MARKETS FINANCING,
          INC. ("BMO"), as syndication agent, and COMPASS BANK ("Compass"), as
          documentation agent, the lenders now or hereafter signatories hereto from
          time
          to time (the lenders currently signatory parties hereto and such additional
          lenders hereafter becoming signatory parties hereto from time to time,
          each
          being sometimes referred to herein, individually, as a "Lender," and
          collectively as the "Lenders"); and BOk as administrative agent for the
          Lenders
          (in such capacity, herein referred to as the "Administrative
          Agent").

         

        RECITALS

         

        A. The
          Borrowers, inter
          alia,
          BOk, as
          the administrative agent for the Existing Lenders (defined herein), and
          the
          financial institutions named and defined therein as lenders signatory parties
          thereto (collectively, the "Existing Lenders") are parties to that certain
          Credit Agreement dated as of January 30, 2004 (the "Existing Credit Agreement"),
          pursuant to which the Existing Lenders provided certain loans and extensions
          of
          revolving credit to the Borrowers signatory parties thereto (all indebtedness
          arising and all obligations, including contingent liabilities on letters
          of
          credit issued pursuant to the Existing Credit Agreement are collectively
          called
          the "Existing Indebtedness"); and

         

        B. Unit
          has
          requested the Co-Arrangers to (i) arrange for the refinancing of any Existing
          Indebtedness and the commitments issued in the Existing Credit Agreement,
          and
          (ii) provide financing for general working capital requirements for (a)
          exploration, development, production and acquisition of Oil and Gas Properties,
          (b) contract drilling services, (c) gas gathering systems, gas processing
          plants
          and other midstream assets, (d) issuance of standby Letters of Credit;
          and (e)
          general corporate purposes of the Borrowers 

         

        C. As
          a
          condition to obtaining the financing contemplated hereby, Borrowers have
          agreed
          to refinance any Existing Indebtedness in full with funds to be made available
          under this Agreement; and

         

        D. The
          Lenders hereto desire to appoint BOk as Administrative Agent for the Lenders,
          and Borrowers desire to obtain the Commitments (i) to refinance any Existing
          Indebtedness, and (ii) for other purposes permitted by the terms of this
          Agreement; and

         

        E. After
          giving effect to the refinancing of any Existing Indebtedness and extinguishment
          of the commitments of the Existing Lenders and the replacement thereof
          by the
          Commitments issued pursuant to this Agreement, the several 

         

        
          
            
            

          

          
            
            

            
            

          

          
            
            
(but
            not
            joint) Commitment (as herein defined) of each Lender hereunder will be
            as set
            forth on the Lenders Schedule annexed hereto as Schedule 2; and


        

         

        F. Pursuant
          to a separate agreement among BOk and Borrowers, BOk and B of A have been
          appointed Co-Arrangers, BMO has been appointed Syndication Agent and Compass
          Bank has been appointed Documentation Agent for this Agreement;

         

        NOW,
          THEREFORE, the parties hereto agree as follows:

         

        ARTICLE
          I

        DEFINITIONS

         

        1.1  Defined
          Terms.
          As used
          in this Agreement, the following terms have the meaning specified below
          or in
          the sections and subsections referred to below:

         

        "Acquisition"
          means any transaction, or any series of related transactions, consummated
          on or
          after the date of this Agreement, by which the Borrowers or any of their
          Subsidiaries (i) acquires, by any means, any going business or all or
          substantially all of the assets of any Person, (ii) directly or indirectly
          acquires (in one transaction or as the most recent transaction in a series
          of
          transactions) at least a majority (in number of votes) of the securities
          of a
          corporation which have ordinary voting power for the election of directors
          (other than securities having such power only by reason of the happening
          of a
          contingency) or a majority (by percentage or voting power) of the outstanding
          ownership interests of a partnership or limited liability company, or (iii)
          acquire Oil and Gas Properties and ancillary assets, gas gathering systems
          and/or gas processing plants or drilling rigs and ancillary
          equipment.

         

        "Administrative
          Agent" means BOk in its capacity as contractual administrative agent of
          the
          Lenders pursuant to Article XIII, and any successor Administrative Agent
          under
          Article XIII.

         

        "Advance"
          means a borrowing under Article II, (i) made by the Lenders on the same
          Borrowing Date, or (ii) converted or continued by the Lenders on the same
          date
          of conversion or continuation, consisting, in either case, of the aggregate
          amount of the several Loans of the same type (either Floating Rate Advance
          or
          Eurodollar Advance) and, in the case of Eurodollar Loans, for the same
          Interest
          Period.

         

        "Affiliate"
          of any Person means any other Person directly or indirectly controlling,
          controlled by or under common control with such Person. A Person will be
          deemed
          to control another Person if the controlling Person owns 10% or more of
          any
          class of voting securities (capital stock, general or limited partnership
          units
          or interests, limited liability company membership interests or association
          or
          other business entity shares, participations, rights or other equivalent
          ownership interests, however designated) of the controlled Person or possesses,
          directly or indirectly, the power to direct or cause the direction of the
          management or policies of the controlled Person, whether through ownership
          of
          stock, by contract or otherwise. 

         

        "Agent
          Fee Letter" means the separate letter agreement between and among the Borrowers
          and the Administrative Agent setting forth the annual agency fee
          arrangements.

         

        
          
            2

          

          
            
            

            
            

          

          
            
            

          

        

        "Aggregate
          Commitment" means the total of the Commitments of all Lenders, as adjusted
          from
          time to time pursuant to the terms hereof; provided that the Aggregate
          Commitment will never exceed the lesser of (i) the Borrowing Base, or (ii)
          the
          Maximum Credit Amount.

         

        "Aggregate
          Outstanding Credit Exposure" means, at any time, the aggregate of the
          Outstanding Credit Exposure of all the Lenders.

         

        "Agreement"
          means this Credit Agreement, as it may be amended, modified, supplemented
          or
          restated and in effect from time to time.

         

        "Alternate
          Base Rate" means, for any day, a rate of interest per annum equal to the
          higher
          of (i) the Prime Rate for such day or (ii) the sum of the Federal Funds
          Effective Rate for such day plus one-half of one percent per annum (0.50%),
          based on the number of days elapsed in an actual 365-366 day year.

         

        "Applicable
          Margin" means the percentage rate per annum set forth in the Pricing
          Schedule.

         

        "Authorized
          Officer" means any of the president, the chief financial officer, any vice
          president, the treasurer or any assistant treasurer of the Borrowers, acting
          singly.

         

        "Available
          Aggregate Commitment" means, at any time, the Aggregate Commitment then
          in
          effect minus the Aggregate Outstanding Credit Exposure at such
          time.

         

        "B
          of A"
          means Bank of America, N.A., its successor and permitted assigns. 

         

        "BMO"
          means BMO Capital Markets Financing, Inc., its successors and permitted
          assigns.

         

        "BOk"
          means Bank of Oklahoma, National Association, and its successors and permitted
          assigns.

         

        "BOKF"
          means Bank of Oklahoma Financial Corporation and its successors.

         

        "Borrowers"
          means Unit, and its existing Material Subsidiaries, and their respective
          successors and assigns, including any receiver, trustee or
          debtor-in-possession.

         

        "Borrowing
          Base" means, at the particular time in question, either the amount provided
          for
          in Section 2.6.1 or the amount otherwise determined in accordance with
          the
          remaining provisions of Section 2.6.

         

        "Borrowing
          Base Properties" means the Oil and Gas Properties and Superior Cash Flow
          evaluated by Lenders for purposes of establishing the Borrowing
          Base.

         

        "Borrowing
          Base Usage Percentage" means, for any day, the percentage equal to the
          quotient
          of (i) the Aggregate Outstanding Credit Exposure on such day, divided by
          (ii)
          the Borrowing Base as initially set by the Lenders 

         

        
          
            3

          

          
            
            

            
            

          

          
            
            
under
            Section 2.6.1 (and as subsequently set by the Lenders under Section 2.6.2
            or
            other provisions of Section 2.6 (excluding Section 2.6.3)).

        

         

        "Borrowing
          Date" means a date on which an Advance is made hereunder.

         

        "Borrowing
          Notice" is defined in Section 2.9.

         

        "Business
          Day" means (i) with respect to any borrowing, payment or rate selection
          of
          Eurodollar Advances, a day (other than a Saturday or Sunday) on which banks
          generally are open in Tulsa, Oklahoma, and New York City, New York, for
          the
          conduct of substantially all of their commercial lending activities, interbank
          wire transfers can be made on the Fedwire system and dealings in United
          States
          dollars are carried on in the London interbank market and (ii) for all
          other
          purposes, a day (other than a Saturday or Sunday) on which banks generally
          are
          open in Tulsa, Oklahoma, for the conduct of substantially all of their
          commercial lending activities and interbank wire transfers can be made
          on the
          Fedwire system.

         

        "Capitalized
          Lease" of a Person means any lease of Property by such Person as lessee
          which
          would be capitalized on a balance sheet of such Person prepared in accordance
          with GAAP.

         

        "Capitalized
          Lease Obligations" of a Person means the amount of the obligations of such
          Person under Capitalized Leases which would be shown as a liability on
          a balance
          sheet of such Person prepared in accordance with GAAP.

         

        "Cash
          Equivalent Investments" means (i) short-term obligations of, or fully guaranteed
          by, the United States of America, (ii) commercial paper rated A-1 or better
          by
          S&P or P-1 or better by Moody's, (iii) demand deposit accounts maintained
          in
          the ordinary course of business, and (iv) certificates of deposit issued
          by and
          time deposits with commercial banks (whether domestic or foreign) having
          capital
          and surplus in excess of $100,000,000; provided in each case that the same
          provides for payment of both principal and interest (and not principal
          alone or.
          interest alone) and is not subject to any contingency regarding the payment
          of
          principal or interest.

         

        "Change
          in Control" means the acquisition by any Person, or two or more Persons
          acting
          in concert, of beneficial ownership (within the meaning of Rule 13d-3 of
          the
          Securities and Exchange Commission under the Securities Exchange Act of
          1934) of
          30% or more of the outstanding shares of voting stock of the
          Borrowers.

         

        "Code"
          means the Internal Revenue Code of 1986, as amended, reformed or otherwise
          modified from time to time.

         

        "Commitment"
          means, for each Lender, the obligation of such Lender to make Loans to,
          and
          participate in LCs issued on the application of, the Borrowers in an aggregate
          amount not exceeding the amount set forth on the Lenders Schedule or as
          set
          forth in any Notice of Assignment relating to any assignment that has become
          effective under Section 14.3.2, as such amount may be modified from time
          to time
          under the terms hereof; provided that no Lender's Commitment will ever
          exceed
          the lesser of such Lender's Pro Rata Share of (i) the Borrowing Base, or
          (ii)
          Maximum Credit Amount.

         

        
          
            4

          

          
            
            

            
            

          

          
            
            

          

        

        "Commitment
          Fee Rate" means, at any time, the per annum percentage rate at which commitment
          fees are accruing on the Available Aggregate Commitment under Section 2.5.3
          at
          such time at the rate set forth in the Pricing Schedule.

         

        "Consolidated
          EBITDA" means Consolidated Net Income plus, to the extent deducted from
          revenues
          in determining Consolidated Net Income, (i) Consolidated Interest Expense,
          (ii)
          expense for income and income based taxes paid or accrued, (iii) depreciation,
          depletion, amortization and impairment, including without limitation, impairment
          of goodwill, and (iv) any non-cash items associated with mark to market
          accounting, all calculated for the Borrowers and their Subsidiaries on
          a
          consolidated basis.

         

        "Consolidated
          Interest Expense" means, for any period with respect to any Person, the
          amount
          which, in conformity with GAAP, would be set forth opposite the caption
          "interest expense" or any like caption (including without limitation, imputed
          interest included in payments under any Capitalized Lease) on a consolidated
          income statement of such Person and the Subsidiaries for such period excluding
          the amortization of any original issue discount.

         

        "Consolidated
          Net Income" means, with reference to any period, the net income (or loss)
          of the
          Borrowers and their Subsidiaries calculated on a consolidated basis for
          such
          period.

         

        "Consolidated
          Net Worth" means the sum of (a) the par value of Unit's consolidated capital
          stock (excluding treasury stock), plus (b) Unit's consolidated additional
          paid-in capital, plus (c) the amount of Unit's consolidated retained earnings
          plus, to the extent deducted from retained earnings, impairment of its
          drilling
          rigs, Oil and Gas Properties and midstream assets; excluding, however,
          from such
          calculations assets and liabilities representing a valuation account arising
          from the application of SFAS 133, or 143 as applicable, subsequent to March
          31,
          2007. 

         

        "Contingent
          Obligation" of a Person means any agreement, undertaking or arrangement
          by which
          such Person assumes, guarantees, endorses, contingently agrees to purchase
          or
          provide funds for the payment of, or otherwise becomes or is contingently
          liable
          on, the obligation or liability of any other Person, or agrees to maintain
          the
          net worth or working capital or other financial condition of any other
          Person,
          or otherwise assures any creditor of such other Person against loss, including,
          without limitation, any comfort letter, take-or-pay contract or the obligations
          of any such Person as general partner of a partnership with respect to
          the
          liabilities of the partnership.

         

        "Contingent
          Obligations Schedule" means Schedule 7.

         

        "Controlled
          Group" means all members of a controlled group of corporations or other
          business
          entities and all trades or businesses (whether or not incorporated) under
          common
          control which, together with the Borrowers or any of their respective
          Subsidiaries, are treated as a single employer under Section 414 of the
          Code.

         

        "Conversion/Continuation
          Notice" is defined in Section 2.10.

         

        "Credit
          Extension" means the making of an Advance or the issuance of a LC
          hereunder.

         

        
          
            5

          

          
            
            

            
            

          

          
            
            

          

        

        "Credit
          Extension Date" means the Borrowing Date for an Advance or the issuance
          date for
          a LC.

         

        "Credit
          Parties" means, collectively, the Borrowers and any Subsidiary Guarantors,
          and
          "Credit Party" means any one of them.

         

        "Default"
          means an event described in Article X prior to the lapse of any grace or
          curative period or the giving of notice, or both, as applicable.

         

        "Determination
          Date" is defined in Section 2.6.2.

         

        "Disclosure
          Schedule" means Schedule 3.

         

        "Engineered
          Value" means, at the time of determination, the future net revenues of
          the oil
          and gas portion of the Borrowing Base Properties calculated by Administrative
          Agent and the Required Lenders using the pricing parameters and discount
          rate
          currently being used by Administrative Agent.

         

        "Engineering
          Report" means the Initial Engineering Report and each engineering report
          delivered pursuant to Section 6.1(vii).

         

        "Environmental
          Laws" means any and all federal, state, local and foreign statutes, laws,
          judicial decisions, regulations, ordinances, rules, judgments, orders,
          decrees,
          plans, injunctions, permits, concessions, grants, franchises, licenses,
          agreements and other governmental restrictions relating to (i) the protection
          of
          the environment, (ii) the effect of the environment on human health, (iii)
          emissions, discharges or releases of pollutants, contaminants, hazardous
          substances or wastes into surface water, ground water or land, or (iv)
          the
          manufacture, processing, distribution, use, treatment, storage, disposal,
          transport or handling of pollutants, contaminants, hazardous substances
          or
          wastes or the clean-up or other remediation thereof.

         

        "Equity"
          means shares of capital stock or a partnership, profits, capital, member
          or
          other equity interest, or options, warrants or any other rights to substitute
          for or otherwise acquire the capital stock or a partnership, profits, capital,
          member or other equity interest of any Person.

         

        "ERISA"
          means the Employee Retirement Income Security Act of 1974, as amended from
          time
          to time, and any rule or regulation issued thereunder.

         

        "Eurodollar
          Advance" means an Advance which, except as otherwise provided in Section
          2.12,
          bears interest at the applicable Eurodollar Rate.

         

        "Eurodollar
          Base Rate" means, with respect to a Eurodollar Advance for the relevant
          Interest
          Period: (a) the interest rate per annum equal to the rate determined by
          the
          Administrative Agent to be the offered rate that appears on the page of
          the
          Telerate Screen that displays an average British Bankers' Association Interest
          Settlement Rate (such page currently being page number 3750) for deposits
          in
          U.S. dollars (for delivery on the first day of such Interest Period) as
          reported
          by any generally recognized financial information service, determined as
          of
          approximately 11:00 a.m. (London time) three (3) Business Days prior to
          the
          first day of such Interest Period, and having a term equivalent to such
          Interest
          Period, provided that, in the event the rate referenced in subsection (a)
          does
          not appear on such page or 

         

        
          
            6

          

          
            
            

            
            

          

          
            
            
such
            service is not available to the Administrative Agent, the applicable
            Eurodollar
            Base Rate for the relevant Interest Period will instead be the rate determined
            by the Administrative Agent to be the rate at which BOk or one of its
            Affiliate
            banks offers to place deposits in U.S. dollars with first-class banks
            in the
            London interbank market at approximately 11:00 a.m. (London time) three
            (3)
            Business Days prior to the first day of such Interest Period, in the
            approximate
            amount of BOk's relevant Eurodollar Loan and having a maturity equal
            to such
            Interest Period.

        

         

        "Eurodollar
          Loan" means a Loan which, except as otherwise provided in Section 2.12,
          bears
          interest at the applicable Eurodollar Rate.

         

        "Eurodollar
          Rate" means, with respect to any Interest Period, an interest rate per
          annum
          equal to the sum of (i) the quotient of (a) the Eurodollar Base Rate applicable
          to such Interest Period, divided by (b) one minus the Reserve Requirement
          (expressed as a decimal) applicable to such Interest Period, plus (ii)
          the
          Applicable Margin, based on a 360 day year.

         

        "Event
          of
          Default" means any event described in Article X 

         

        "Excluded
          Accounts" has the meaning assigned in Section 6.10.

         

        "Excluded
          Taxes" means, in the case of each Lender and the Administrative Agent,
          taxes
          imposed on its overall net income, and franchise taxes imposed on it, by
          (i) the
          jurisdiction under the laws of which such Lender or the Administrative
          Agent is
          incorporated or organized or (ii) the jurisdiction in which the Administrative
          Agent's or such Lender's principal executive office is located.

         

        "Existing
          Credit Agreement" has the meaning assigned to such term in Recital
          A.

         

        "Existing
          Indebtedness " has the meaning assigned to such term in Recital A.

         

        "Existing
          Subsidiaries" means Superior Pipeline Company, L.L.C., an Oklahoma limited
          liability company, Unit Drilling Company, an Oklahoma corporation, Unit
          Petroleum Company, an Oklahoma corporation, Unit Energy Canada, Inc., an
          Alberta
          Canada corporation, and Unit Texas Drilling, L.L.C., an Oklahoma limited
          liability company, and other Subsidiaries listed on Schedule 3.

         

        "Facility
          Termination Date" means the date which is five (5) years from the date
          of this
          Agreement, or any earlier date on which the Aggregate Commitment is reduced
          to
          zero or otherwise terminated pursuant to the terms of this
          Agreement.

         

        "Federal
          Funds Effective Rate" means, for any day, an interest rate per annum equal
          to
          the weighted average of the rates on overnight Federal funds transactions
          with
          members of the Federal Reserve System arranged by Federal funds brokers
          on such
          day, as published for such day (or, if such day is not a Business Day,
          for the
          immediately preceding Business Day) by the Federal Reserve Bank of New
          York, or,
          if such rate is not so published for any day which is a Business Day, the
          average of the quotations at approximately 10:00 a.m. (Tulsa time) on such
          day
          on such transactions received by the Administrative Agent from three Federal
          funds brokers of recognized standing selected by the Administrative Agent
          in its
          sole discretion.

         

        
          
            7

          

          
            
            

            
            

          

          
            
            

          

        

        "Financial
          Contract" of a Person means (i) any exchange-traded or over-the-counter
          futures,
          forward, swap, hedge or option contract or other financial instrument with
          similar characteristics, and (ii) any Rate Management Transaction.

         

        "Floating
          Rate" means, for any day, a rate per annum equal to the Alternate Base
          Rate for
          such day, in each case changing when and as the Alternate Base Rate
          changes.

         

        "Floating
          Rate Advance" means an Advance which, except as otherwise provided in Section
          2.12, bears interest at the Floating Rate.

         

        "Floating
          Rate Loan" means a Loan which, except as otherwise provided in Section
          2.12,
          bears interest at the Floating Rate.

         

        "GAAP"
          means generally accepted accounting principles as in effect from time to
          time in
          the United States, applied in a manner consistent with that used in preparing
          the financial statements referred to in Section 5.4.

         

        "Highest
          Lawful Rate" means, on any day with respect to each Lender to whom Obligations
          are owed, the maximum non-usurious rate of interest that such Lender is
          permitted under applicable law to contract for, take, charge or receive
          with
          respect to such Obligations for such day. All determinations herein of
          the
          Highest Lawful Rate, or of any interest rate determined by reference to
          the
          Highest Lawful Rate, will be made separately for each Lender as appropriate
          to
          assure that the Loan Documents are not construed to obligate any Person
          to pay
          interest to any Lender at a rate in excess of the Highest Lawful Rate applicable
          to such Lender.

         

        "Hydrocarbon
          Interests" shall mean all rights, titles, interests and estates now or
          hereafter
          acquired in and to (i) Hydrocarbons and (ii) oil and gas leases, oil, gas
          and
          mineral leases, or other liquid or gaseous Hydrocarbon leases, mineral
          fee
          interests, overriding royalty and royalty interests, net profit interests,
          production payment interests, farm outs and farm ins, including any reserved,
          back in or residual interests of whatever nature.

         

        "Hydrocarbons"
          shall mean oil, gas, casinghead gas, drip gasoline, natural gasoline,
          condensate, distillate, liquid hydrocarbons, gaseous hydrocarbons and all
          products refined or separated therefrom.

         

        "Indebtedness"
          of a Person means such Person's (i) obligations for borrowed money, (ii)
          obligations representing the deferred purchase price of Property or services
          (other than accounts payable arising in the ordinary course of such Person's
          business payable on terms customary in the trade), (iii) obligations, whether
          or
          not assumed, secured by Liens or payable out of the proceeds or production
          from
          Property now or hereafter owned or acquired by such Person (other than
          Permitted
          Encumbrances), (iv) obligations which are evidenced by notes, acceptances,
          or
          other instruments, (v) obligations of such Person to purchase securities
          or
          other Property arising out of or in connection with the sale of the same
          or
          substantially similar securities or Property, (vi) Capitalized Lease
          Obligations, (vii) Contingent Obligations, (viii) Financial Contracts.
          including
          Rate Management Obligations, (ix) obligations to reimburse issuers of Letters
          of
          Credit, (x) obligations with respect to payments received in consideration
          of
          oil, gas, or other minerals yet to be acquired or produced at the time
          of
          payment (including obligations under "take-or-pay" contracts to deliver
          gas in
          return for payments already received and the undischarged balance of any
          production payment created by such Person 

         

        
          
            8

          

          
            
            

            
            

          

          
            
            
or
            for
            the creation of which such Person directly or indirectly received payment),
            (xi)
            obligations with respect to other obligations to deliver goods or services
            in
            consideration of advance payments therefor; and (xii) any other obligation
            for
            borrowed money or other financial accommodation which in accordance with
            GAAP
            would be shown as a liability on the consolidated balance sheet of such
            Person.

        

         

        "Initial
          Engineering Report" means the engineering reserve report concerning Oil
          and Gas
          Properties of the Credit Parties prepared by Unit and audited by Ryder
          Scott
          Company effective as of December 31, 2006.

         

        "Interest
          Period" means, with respect to a Eurodollar Advance, a period of one, two,
          three
          or six months commencing on a Business Day selected by Unit pursuant to
          this
          Agreement. Such Interest Period will end on the day which corresponds
          numerically to such date one, two, three or six months thereafter, provided,
          however,
          that if
          there is no such numerically corresponding day in the next, second, third
          or
          sixth succeeding month, such Interest Period will end on the last Business
          Day
          of the next, second, third or sixth succeeding month. If an Interest Period
          would otherwise end on a day which is not a Business Day, such Interest
          Period
          will end on the next succeeding Business Day, provided,
          however,
          that if
          the next succeeding Business Day falls in a new calendar month, such Interest
          Period will end on the immediately preceding Business Day.

         

        "Investment"
          of a Person means any loan, advance (other than commission, travel and
          similar
          advances to officers and employees made in the ordinary course of business),
          extension of credit (other than accounts receivable arising in the ordinary
          course of business on terms customary in the trade) or contribution of
          capital
          by such Person; stocks, bonds, mutual funds, partnership interests, notes,
          debentures or other securities owned by such Person; any deposit accounts
          and
          certificate of deposit owned by such Person; and structured notes, derivative
          financial instruments and other similar instruments or contracts owned
          by such
          Person.

         

        "LC"
          is
          defined in Section 2.19.1.

         

        "LC
          Application" is defined in Section 2.19.3.

         

        "LC
          Fee"
          is defined in Section 2.19.4.

         

        "LC
          Issuer" means BOk (or any subsidiary or affiliate of BOk designated by
          BOk) or
          any other Lender in its capacity as issuer of LCs hereunder.

         

        "LC
          Obligations" means, at any time, the sum, without duplication, of (i) the
          aggregate undrawn stated amount under all LCs outstanding at such time
          plus (ii)
          the aggregate unpaid amount at such time of all Reimbursement
          Obligations.

         

        "LC
          Payment Date" is defined in Section 2.19.5.

         

        "LC
          Sublimit" means $15,000,000 until otherwise agreed in writing among the
          LC
          Issuer, Unit and the Required Lenders

         

        "Lenders"
          means the lending institutions now or hereafter listed on the signature
          pages of
          this Agreement and their respective successors and permitted
          assigns.

         

        
          
            9

          

          
            
            

            
            

          

          
            
            

          

        

        "Lenders
          Schedule" means Schedule 2.

         

        "Letter
          of Credit" of a Person means a letter of credit or similar instrument which
          is
          issued upon the application of such Person or upon which such Person is
          an
          account party or for which such Person is in any way liable.

         

        "Lien"
          means any lien (statutory or other), mortgage, pledge, hypothecation,
          assignment, deposit arrangement, encumbrance or preference, priority or
          other
          security agreement or preferential arrangement of any kind or nature whatsoever
          (including, without limitation, the interest of a vendor or lessor under
          any
          conditional sale, Capitalized Lease or other title retention
          agreement).

         

        "Loan"
          means, with respect to a Lender, that Lender's Advances made pursuant to
          Article
          II (or any conversion or continuation thereof).

         

        "Loan
          Documents" means this Agreement, the LC Applications and any Notes issued
          pursuant to Section 2.14, and each Subsidiary Guaranty.

         

        "Long
          Term Debt" means all outstanding long term liabilities of the Borrowers
          in
          accordance with GAAP excluding deferred taxes and the plugging and abandonment
          accrued liabilities described in Section 7.9(v).

         

        "Material
          Adverse Effect" means a material adverse effect on (i) the business, Property,
          condition (financial or otherwise), results of operations, or prospects
          of the
          Borrowers and their Subsidiaries taken as a whole (taking into account
          the
          present value of any indemnification in favor of the Borrowers or any applicable
          insurance coverage), (ii) the ability of any of the Borrowers to perform
          their
          obligations under the Loan Documents to which it is a party, or (iii) the
          validity or enforceability of any of the Loan Documents or the rights or
          remedies of the Administrative Agent, the LC Issuer or the Lenders
          thereunder.

         

        "Material
          Indebtedness" means Indebtedness in an outstanding principal amount of
          $10,000,000 or more (or the equivalent thereof in any currency other than
          U.S.
          dollars).

         

        "Material
          Indebtedness Agreement" means any agreement under which any Material
          Indebtedness was created or is governed or which provides for the incurrence
          of
          Indebtedness in an amount which would constitute Material Indebtedness
          (whether
          or not an amount of Indebtedness constituting Material Indebtedness is
          outstanding thereunder).

         

        "Material
          Subsidiary" means at any time a Subsidiary of any of the Borrowers having
          (i) at
          least ten percent (10%) of the consolidated total assets of the Borrowers
          and
          their Subsidiaries (determined as of the last day of the most recent fiscal
          quarter of the Borrowers) or (ii) at least ten percent (10%) of the consolidated
          revenues of the Borrowers and their Subsidiaries for the fiscal year of
          Unit
          then most recently ended. For purposes of this Agreement, "Material Subsidiary"
          shall not include any Subsidiary of Unit which is also a Borrower. 

         

        "Maximum
          Credit Amount" means such amount that is agreed to in writing by the Borrowers
          and the Lenders as the maximum amount of Credit Extensions available to
          the
          Borrowers under Article II of this Agreement from Lenders.

         

        
          
            10

          

          
            
            

            
            

          

          
            
            

          

        

        "Modify"
          and "Modification" are defined in Section 2.19.1.

         

        "Moody's"
          means Moody's Investors Service, Inc.

         

        "Multiemployer
          Plan" means a Plan maintained pursuant to a collective bargaining agreement
          or
          any other arrangement to which the Borrowers or any member of the Controlled
          Group is a party to which more than one employer is obligated to make
          contributions.

         

        "Note"
          is
          defined in Section 2.14.

         

        "Obligations"
          means all unpaid principal of and accrued and unpaid interest on the Loans,
          all
          Reimbursement Obligations, all Rate Management Obligations under Financial
          Contracts with any Lender or any Lender Affiliate, all accrued and unpaid
          fees
          and all expenses, reimbursements, indemnities and other obligations of
          the
          Borrowers to the Lenders or to any Lender, the Administrative Agent, the
          LC
          Issuer or any indemnified party arising under the Loan Documents.

         

        "Oil
          and
          Gas Properties" means all Hydrocarbon Interests from time to time owned
          by any
          Credit Party or in which one of the Credit Parties has an interest, including
          without limitation, (i) any interests of any Credit Party in such Hydrocarbon
          Interest in the Property now or hereafter pooled or unitized with such
          Hydrocarbon Interests, (ii) all presently existing or future unitization,
          pooling agreements and declarations of pooled units and the units created
          in
          connection therewith (including without limitation all units created under
          orders, regulations and rules of any Governmental Authority) which may
          affect
          all or any portion of such Hydrocarbon Interests, (iii) all operating
          agreements, contracts and other agreements which relate to any of such
          Hydrocarbon Interests or the production, sale, purchase, exchange or processing
          of Hydrocarbons from or attributable to such Hydrocarbon Interests, (iv)
          all
          Hydrocarbons in and under and which may be produced and saved or attributable
          to
          such Hydrocarbon Interests, including as-extracted collateral and all oil
          in
          tanks and all rents, issues, profits, proceeds, products, revenues and
          other
          incomes from or attributable to such Hydrocarbon Interests, (v) all tenements,
          hereditaments, appurtenances and Property in any manner appertaining, belonging,
          affixed or incidental to such Hydrocarbon Interests, (vi) and all Property,
          rights, titles, interests and estates described or referred to above, including
          any and all Property, real or personal, now owned or hereinafter acquired
          and
          situated upon, used, held for use or useful in connection with the operating,
          working or development of any of such Hydrocarbon Interests or Property
          (excluding drilling rigs, automotive equipment or other personal property
          which
          may be on such premises for the purpose of drilling a well or for other
          similar
          temporary uses), and (vii) any and all oil wells, gas wells, injection
          wells or
          other wells, buildings, structures, fuel separators, liquid extraction
          plants,
          plant compressors, pumps, pumping units, field gathering systems, tanks
          and tank
          batteries, fixtures, valves, fittings, machinery and parts, engines, boilers,
          meters, apparatus, equipment, appliances, tools, implements, cables, wires,
          towers, casing, tubing and rods, surface leases, rights-of-way, easements
          and
          servitudes together with all additions, substitutions, replacements, accessions
          and attachments to any and all of the foregoing, in each case limited to
          the
          interest of such applicable Credit Party in such assets.

         

        "Other
          Taxes" is defined in Section 3.3(ii).

         

        
          
            11

          

          
            
            

            
            

          

          
            
            

          

        

        "Outstanding
          Credit Exposure" means, as to any Lender at any time, the sum of (i) the
          aggregate principal amount of its Loans outstanding at such time, plus
          (ii) an
          amount equal to its Pro Rata Share of the LC Obligations at such
          time.

         

        "Participants"
          is defined in Section 14.2.1.

         

        "Payment
          Date" means the day prescribed in Section 2.16 for payment of Eurodollar
          Loans
          and Floating Rate Loans, respectively.

         

        "PBGC"
          means the Pension Benefit Guaranty Corporation, or any successor
          thereto.

         

        "Permitted
          Encumbrances" means any Lien permitted by Section 7.6.

         

        "Person"
          means any natural person, corporation, firm, joint venture, partnership,
          limited
          liability company, association, enterprise, trust or other entity or
          organization, or any government or political subdivision or any agency,
          department or instrumentality thereof.

         

        "Plan"
          means an employee pension benefit plan which is covered by Title IV of
          ERISA or
          subject to the minimum funding standards under Section 412 of the Code
          as to
          which the Borrowers or any member of the Controlled Group may have any
          liability.

         

        "Pricing
          Schedule" means Schedule 1.

         

        "Prime
          Rate" means the annual rate of interest set by BOKF in its sole discretion
          as
          the BOKF National Prime Rate, on a daily basis as published by BOKF from
          time to
          time (the "Index"), which shall be the rate used by BOKF as a base or standard
          for pricing purposes, and which shall not necessarily be its "best" or
          lowest
          rate. The Borrowers acknowledge and stipulate that the Lenders may make
          loans
          based on other rates or indices as well. Should the Index become unavailable
          during the term of the Loans evidenced by the Notes and/or governed hereby
          or by
          Financial Contracts or should BOKF otherwise cease to publish or announce
          a
          prime or base rate, or should it be merged, consolidated, liquidated or
          dissolved in such a manner that it loses its separate corporate or banking
          identity, then the Index shall be a substitute index selected and designated
          by
          the Administrative Agent and concerning which Unit is notified by the
          Administrative Agent. Any change in the Prime Rate shall be effective as
          of the
          date of the change but the Prime Rate shall not change more often than
          once each
          day. Under no circumstances will the interest rate on the Notes be more
          than the
          Highest Lawful Rate.

         

        "Pro
          Rata
          Share" means, with respect to a Lender, a portion equal to a fraction the
          numerator of which is such Lender's Commitment and the denominator of which
          is
          the Aggregate Commitment.

         

        "Property"
          of a Person means any and all property, whether real, personal, tangible,
          intangible, or mixed, of such Person, or other assets owned, leased or
          operated
          by such Person. 

         

        "Purchasers"
          is defined in Section 14.3.1.

         

        "Rate
          Management Obligations" of a Person means any and all obligations of such
          Person, whether absolute or contingent and howsoever and whensoever created,
          arising, evidenced or acquired (including all renewals, 

         

        
          
            12

          

          
            
            

            
            

          

          
            
            
extensions,
            supplements, replacements and modifications thereof and substitutions
            therefor),
            under (i) any and all Financial Contracts, including Rate Management
            Transactions, and (ii) any and all cancellations, buy backs, reversals,
            terminations or assignments of any Financial Contracts, including Rate
            Management Transactions.

        

         

        "Rate
          Management Transaction" means any transaction (including an agreement with
          respect thereto) now existing or hereafter entered by the Borrowers which
          is a
          rate swap, basis swap, hedge, forward rate transaction, commodity swap,
          commodity option, equity or equity index swap, equity or equity index option,
          bond option, interest rate option, foreign exchange transaction, cap
          transaction, floor transaction, collar transaction, forward transaction,
          currency swap transaction, cross-currency rate swap transaction, currency
          option
          or any other similar transaction or price/commodity protection device (including
          any option with respect to any of these transactions) or any combination
          thereof, whether linked to one or more interest rates, foreign currencies,
          commodity prices, equity prices or other financial measures. Notwithstanding
          the
          foregoing, a "Rate Management Transaction" will not include any contract
          for the
          purchase and sale of natural gas or oil entered into in the ordinary course
          of
          business and on customary trade terms.

         

        "Redetermination"
          means a Scheduled Redetermination or a Special Redetermination. 

         

        "Regulation
          D" means Regulation D of the Board of Governors of the Federal Reserve
          System as
          from time to time in effect and any successor thereto or other regulation
          or
          official interpretation of said Board of Governors relating to reserve
          requirements applicable to member banks of the Federal Reserve
          System.

         

        "Regulation
          U" means Regulation U of the Board of Governors of the Federal Reserve
          System as
          from time to time in effect and any successor or other regulation or official
          interpretation of said Board of Governors relating to the extension of
          credit by
          banks for the purpose of purchasing or carrying margin stocks applicable
          to
          member banks of the Federal Reserve System.

         

        "Reimbursement
          Obligations" means, at any time, the aggregate of all obligations of the
          Borrowers then outstanding under Section 2.19 to reimburse the LC Issuer
          for
          amounts paid by the LC Issuer in respect of any one or more drawings under
          LCs.

         

        "Reportable
          Event" means a reportable event as defined in Section 4043 of ERISA, with
          respect to which the notice requirements to the PBGC have not been waived,
          provided, however, that a failure to meet the minimum funding standard
          of
          Section 412 of the Code and of Section 302 of ERISA will be a Reportable
          Event
          regardless of the issuance of any such waiver of the notice requirement
          in
          accordance with either Section 4043(a) of ERISA or Section 412(d) of the
          Code.

         

        "Required
          Lenders" means Lenders in the aggregate having at least 66.67% of the Aggregate
          Commitment or, if the Aggregate Commitment has been terminated, Lenders
          in the
          aggregate holding at least two-thirds (66.67%) of the Aggregate Outstanding
          Credit Exposure.

         

        
          
            13

          

          
            
            

            
            

          

          
            
            

          

        

        "Reserve
          Requirement" means, with respect to an Interest Period, the maximum aggregate
          reserve requirement (including all basic, supplemental, marginal and other
          reserves) which is imposed under Regulation D on Eurocurrency
          liabilities.

         

        "S&P"
          means Standard and Poor's Ratings Services, a division of The McGraw Hill
          Companies, Inc.

         

        "Sale
          and
          Leaseback Transaction" means any sale or other transfer of Property by
          any
          Person with the intent to lease such Property as lessee.

         

        "Scheduled
          Redetermination" means any redetermination of the Borrowing Base under
          Sections
          2.6.4 or 2.6.5 in accordance with Section 2.6.2.

         

        "SEC"
          means the Securities and Exchange Commission.

         

        "Single
          Employer Plan" means a Plan maintained by the Borrowers or any member of
          the
          Controlled Group for employees of the Borrowers or any member of the Controlled
          Group. 

         

        "Special
          Redetermination" means any redetermination of the Borrowing Base pursuant
          to
          Sections 2.6.4 or 2.6.5.

         

        "Subsidiary"
          of a Person means (i) any corporation more than 50% of the outstanding
          securities having ordinary voting power of which will at the time be owned
          or
          controlled, directly or indirectly, by such Person or by one or more of
          their
          Subsidiaries or by such Person and one or more of their Subsidiaries, or
          (ii)
          any partnership, limited liability company, association, joint venture
          or
          similar business organization more than 50% of the ownership interests
          having
          ordinary voting power of which will at the time be so owned or controlled,
          provided that associations, joint ventures or other relationships (a) which
          are
          established pursuant to a standard form operating agreement or similar
          agreement
          or which are partnerships for purposes of federal income taxation only,
          (b)
          which are not corporations or partnerships (or subject to the Uniform
          Partnership Act) under applicable state applicable law, and (c) whose businesses
          are limited to the exploration, development and operation of oil, gas or
          mineral
          properties and interests owned directly by the parties in such associations,
          joint ventures or relationships, will not be deemed to be "Subsidiaries"
          of such
          Person. Unless otherwise expressly provided, all references herein to a
          "Subsidiary" will mean a Subsidiary of any of the Borrowers (including
          Subsidiary Guarantors).

         

        "Subsidiary
          Guarantor" means each present or future Material Subsidiary and their successors
          and assigns, including any receiver, trustee or debtor in
          possession.

         

        "Subsidiary
          Guaranty" means the Guaranty Agreement, substantially in the form of Exhibit
          E
          to be executed by each Material Subsidiary in favor of the Administrative
          Agent
          for the ratable benefit of the Lenders, with respect to the Obligations
          of the
          Borrowers under this Credit Agreement.

         

        "Subsidiary
          Guaranty Joinder Agreement" means the Joinder Agreement, substantially
          in the
          form of Schedule 1 to the Subsidiary Guaranty, to be executed and delivered
          by
          each new Material Subsidiary in accordance with the provisions of Section
          9.1 of
          this Credit Agreement.

         

        
          
            14

          

          
            
            

            
            

          

          
            
            

          

        

        "Superior
          Cash Flow" means the loan value attributed by the Lenders or Required Lenders,
          as applicable, from time to time to the throughput volume in the pipeline
          systems of Superior in accordance with Section 2.6 of the Credit
          Agreement.

         

        "Syndication
          Agent" means BMO and its successors and permitted assigns.

         

        "Taxes"
          means any and all present or future taxes, duties, levies, imposts, deductions,
          charges or withholdings, and any and all liabilities with respect to the
          foregoing, but excluding Excluded Taxes and Other Taxes.

         

        "Transferee"
          is defined in Section 14.4.

         

        "Unfunded
          Liabilities" means the amount (if any) by which the present value of all
          vested
          and unvested accrued benefits under all Single Employer Plans exceeds the
          fair
          market value of all such Plan assets allocable to such benefits, all determined
          as of the then most recent valuation date for such Plans using PBGC actuarial
          assumptions for single employer plan terminations. 

         

        "Wholly-Owned
          Subsidiary" of a Person means (i) any Subsidiary all of the outstanding
          voting
          securities of which will at the time be owned or controlled, directly or
          indirectly, by such Person or one or more Wholly-Owned Subsidiaries of
          such
          Person, or by such Person and one or more Wholly-Owned Subsidiaries of
          such
          Person, or (ii) any partnership, limited liability company, association,
          joint
          venture or similar business organization 100% of the ownership interests
          having
          ordinary voting power of which will at the time be so owned or
          controlled.

         

        The
          foregoing definitions will be equally applicable to both the singular and
          plural
          forms of the defined terms.

         

        1.2  Exhibits
          and Schedules; Additional Definitions.
          All
          Exhibits and Schedules attached to this Agreement are a part of this Agreement
          for all purposes. Unless the context otherwise requires or unless otherwise
          provided in this Agreement the terms defined in this Agreement which refer
          to a
          particular agreement, instrument or document also refer to and include
          all
          renewals, extensions, modifications, amendments and restatements of such
          agreement, instrument or document, provided that nothing in this section
          will be
          construed to authorize any such renewal, extension, modification, amendment
          or
          restatement.

         

        1.3  Reference
          and Titles.
          All
          references in this Agreement to Exhibits, Schedules, articles, sections,
          subsections and other subdivisions refer to the Exhibits, Schedules, articles,
          sections, subsections and other subdivisions of this Agreement unless expressly
          provided otherwise. Exhibits and Schedules to any Loan Document will be
          deemed
          incorporated by reference in such Loan Document. References to any document,
          instrument, or agreement (a) will include all exhibits, schedules, and
          other
          attachments thereto, and (b) will include all documents, instruments, or
          agreements issued or executed in replacement or restatement thereof. Titles
          appearing at the beginning of any subdivisions are for convenience only
          and do
          not constitute any part of such subdivisions and will be disregarded in
          construing the language contained in such subdivisions. The words "this
          Agreement," "this instrument," "herein," "hereof," "hereby," "hereunder"
          and
          words of similar import refer to this Agreement as a whole and not to any
          particular subdivision unless expressly so limited. The phrases "this section"
          and "this subsection" and similar phrases refer only to the sections or
          subsections hereof in 

         

        
          
            15

          

          
            
            

            
            

          

          
            
            
which
            such phrases occur. The word "or" is not exclusive, and the word "including"
            (in
            its various forms) means "including without limitation." Pronouns in
            masculine,
            feminine and neuter genders will be construed to include any other gender,
            and
            words in singular form will be construed to include the plural and vice
            versa,
            unless the context otherwise requires. 

        

         

        1.4  Accounting
          Terms and Determinations.
          Except
          only as otherwise expressly provided in this Agreement, all accounting
          terms
          will be interpreted, and all financial statements and certificates and
          reports
          as to financial matters required to be delivered to the Administrative
          Agent or
          the Lenders under this Agreement shall be prepared in accordance with GAAP,
          as
          applied on a consistent basis. References to "days" will mean calendar
          days,
          unless the term "Business Day" is used. Unless otherwise specified, references
          herein to any particular Person also refer to its successors and permitted
          assigns.

         

        1.5  Calculations
          and Determinations.
          All
          calculations under the Loan Documents of interest and of fees will be made
          on
          the basis of actual days elapsed (including the first day but excluding
          the
          last) and a year of 360 days except only for interest accruals on Floating
          Rate
          Loans which will be based on the number of days lapsed in a 365-366 day
          year.
          Each determination by a Lender of amounts to be paid under Article III
          or any
          other matters which are to be determined hereunder by a Lender (such as
          any
          Eurodollar Rate, Business Day, Interest Period, or Reserve Requirement)
          will, in
          the absence of manifest error, be conclusive and binding. 

         

        1.6  Joint
          Preparation; Construction of Indemnities and Releases.
          This
          Agreement and the other Loan Documents have been reviewed and negotiated
          by
          sophisticated parties with access to legal counsel and no rule of construction
          will apply hereto or thereto which would require or allow any Loan Document
          to
          be construed against any party because of its role in drafting such Loan
          Document. All indemnification and release provisions of this Agreement
          will be
          construed broadly (and not narrowly) in favor of the Persons receiving
          indemnification or being released.

         

        ARTICLE
          II

        THE
          CREDITS

         

        2.1  Commitments.
          From
          and including the date of this Agreement and up to the Facility Termination
          Date, each Lender severally agrees, on the terms and conditions of this
          Agreement, to (i) make Loans to the Borrowers (on a joint and several liability
          basis) and (ii) participate in LCs issued upon the request of the Borrowers,
          provided that, after giving effect to the making of each such Loan and
          the
          issuance of each such LC, such Lender's Outstanding Credit Exposure does
          not
          exceed its Commitment and the Aggregate Outstanding Credit Exposure does
          not
          exceed the Aggregate Commitment. Subject to the terms of this Agreement,
          Unit,
          as the designated borrowing agent on behalf of all of the Borrowers, may
          borrow,
          repay and re-borrow at any time before the Facility Termination Date. Each
          Lender's Commitment will expire on the Facility Termination Date. The LC
          Issuer
          will issue LCs hereunder on the terms and conditions set forth in Section
          2.19.


         

        2.2  Required
          Payments; Termination.
          All
          unpaid Obligations will be paid in full by the Borrowers on the Facility
          Termination Date.

         

        
          
            16

          

          
            
            

            
            

          

          
            
            

          

        

        2.3  Ratable
          Loans.
          Each
          Advance will be made by the Lenders ratably according to their Pro Rata
          Shares.

         

        2.4  Types
          of Advances.
          The
          Advances may be Floating Rate Advances or Eurodollar Advances, or a combination
          thereof, selected by Unit on behalf of the Borrowers in accordance with
          Sections
          2.9 and 2.10.

         

        2.5  Facility
          Fee; Initial Aggregate Commitment; Maximum Credit Amount; Commitment Fee
          Rate.
          

         

        2.5.1.  A
          facility fee of $687,500 (calculated on the basis of a 25 basis point fee
          for
          the initial Aggregate Commitment described in Section 2.5.2) will be paid
          at
          Closing to the Administrative Agent for the Pro Rata Share benefit of each
          Lender. Any increases in the Aggregate Commitment above the amount designated
          in
          Section 2.5.2 will be contingent upon the Borrowers' payment of a 25 basis
          point
          facility fee on the amount of such increase(s) to the Administrative Agent
          for
          the Pro Rata Share benefit of the Lenders increasing its or their Commitments
          and/or on the Commitment of any additional Lender(s) pursuant to Section
          14.6.

         

        2.5.2.  The
          initial Aggregate Commitment is $275,000,000 and the initial Maximum Credit
          Amount is $400,000,000. Any increase in either the Aggregate Commitment
          or the
          Maximum Credit Amount requires the written consent of all Lenders.

         

        2.5.3.  
          The
          Borrowers agree to pay to the Administrative Agent for the Pro Rata Share
          of
          each Lender a commitment fee equal to the per annum Commitment Fee Rate
          (as set
          forth on the Pricing Schedule) multiplied by the average daily amount of
          the
          Available Aggregate Commitment from the date of this Agreement through
          the
          Facility Termination Date. The commitment fee will be payable on each quarterly
          Payment Date hereafter and on the Facility Termination Date. All accrued
          commitment fees will be payable on the effective date of any termination
          of the
          obligations of the Lenders to make Credit Extensions. 

         

        2.6  Borrowing
          Base.

         

        2.6.1.  Until
          the
          first Determination Date, the parties hereto stipulate that the Borrowing
          Base
          preliminarily set by the Lenders is $425,000,000, subject to the term,
          provisions and limitations hereof (the "Borrowing Base"). 

         

        2.6.2.  By
          March
          1 and September 1 of each year beginning September 1, 2007 Unit will furnish
          to
          each Lender all information, reports and data that Administrative Agent
          has then
          requested concerning the businesses and properties (including the information
          specified in Sections 6.1(vii) and (viii)). The Engineering Report submitted
          to
          the Agent and each Lender by each March 1 will be audited by an independent
          third party engineering firm acceptable to the Agent and dated effective
          no
          earlier than December 31 of the immediately preceding calendar year. The
          Engineering Report submitted to the Agent and each Lender by September
          1 will be
          internally prepared by Unit and dated effective no earlier than June 30
          of such
          year and:

         

        
          
            17

          

          
            
            

            
            

          

          
            
            

          

        

        (a)  By
          each
          April 1 and October 1, commencing October 1, 2007, the Administrative Agent
          will
          submit in writing to the Lenders its proposed Borrowing Base amount


         

        (b)  After
          having received written notice of such proposal by the Administrative Agent,
          all
          of the other Lenders shall have ten (10) Business Days to agree or disagree
          with
          such proposal. If however, within the time prescribed by the preceding
          sentence,
          (i) all the Lenders have not approved in writing the Administrative Agent's
          proposal with respect to an increase in the Borrowing Base, or (ii) Lenders
          holding seventy five percent (75%) of the Aggregate Commitment or, if the
          Aggregate Commitment has been terminated or has expired, Lenders holding
          seventy
          five percent (75%) of the Aggregate Outstanding Credit Exposure (the "Borrowing
          Base Required Lenders") have not affirmatively approved the Administrative
          Agent's proposal with respect to a decrease in, or maintenance of, the
          Borrowing
          Base, the Administrative Agent and, the Lenders shall, within five (5)
          Business
          Days, diligently attempt in good faith to agree upon a new Borrowing
          Base.

         

        (c)  If
          the
          Administrative Agent and the Borrowing Base Required Lenders cannot otherwise
          agree on a redetermination of the Borrowing Base resulting in a decrease
          in or
          the same (maintenance of) Borrowing Base within such additional five (5)
          Business Day period, then the proposed Borrowing Base shall be set at the
          amount
          calculated by the Administrative Agent as the "weighted arithmetic average"
          (as
          hereinafter calculated) of the Borrowing Base, as determined by each individual
          Lender and communicated to the Administrative Agent in writing, and such
          Borrowing Base shall then become the Borrowing Base. For purposes of this
          paragraph, the "weighted arithmetic average" of the Borrowing Base shall
          be
          determined by first multiplying the Borrowing Base proposed in writing
          to the
          Administrative Agent by each Lender by the ratio of such Lender's Percentage
          Share over the sum of the Percentage Shares of all Lenders, and then adding
          the
          results of each such calculation, with the resultant sum being the Borrowing
          Base. In no event shall the foregoing "weighted arithmetic average" be
          employed
          to increase the Borrowing Base unless all Lenders consent in writing thereto.
          

         

        (d)  The
          Administrative Agent will then promptly notify Unit of the new Borrowing
          Base
          amount as determined by the Lenders or the Borrowing Base Required Lenders,
          as
          applicable. Unless within five (5) days following the Administrative Agent's
          notice, Unit makes a designation permitted by Section 2.6.3, the new Borrowing
          Base will be effective as of the date such notice is sent (a "Determination
          Date") provided, however, any increase in the Borrowing Base must be approved
          by
          all Lenders. If Unit so designates a lesser amount for the Borrowing Base,
          such
          designated Borrowing Base shall become effective when the Administrative
          Agent
          receives Unit's written designation, and in either event, the Borrowing
          Base
          will remain in effect until but not including the next date the Borrowing
          Base
          is redetermined other than designations permitted by Section 2.6.3.


         

        
          
            18

          

          
            
            

            
            

          

          
            
            

          

        

        (e)  If
          Unit
          does not furnish all such information, reports and data by the date specified
          in
          this subsection, Administrative Agent may designate the Borrowing Base
          at any
          amount which the Lenders or the Borrowing Base Required Lenders, as applicable,
          determine and may redesignate the Borrowing Base from time to time until
          each
          Lender receives all such information, reports and data, at which time the
          Lenders or the Borrowing Base Required Lenders, as applicable, may designate
          a
          new Borrowing Base. Required Lenders will determine the Borrowing Base
          based on
          (i) the loan value which they in their discretion assign to the various
          Borrowers' Oil and Gas Properties being evaluated, (ii) the loan value,
          as the
          Lenders shall reasonably attribute to be assigned to Superior Cash Flow,
          and
          (iii) any other credit factors (including without limitation the assets,
          liabilities, cash flow, hedged and unhedged exposure to price, foreign
          exchange
          rate, and interest rate changes, business, properties, prospects, management
          and
          ownership of Credit Parties) as the Lenders deem significant. The Lenders
          and
          the Administrative Agent have no obligation to agree on or designate the
          Borrowing Base at any particular amount, whether in relation to the Aggregate
          Commitment or otherwise.

         

        2.6.3.  Following
          the Administrative Agent's notice to Unit of the Borrowing Base amount
          determined under Section 2.6.2, Unit, on behalf of the Borrowers, may (i)
          once
          during each Scheduled Redetermination six (6) month period and (ii) on
          each such
          additional occasion during such six (6) month period following Unit's
          successfully close the issuance of debt or equity securities permitted
          by this
          Agreement, designate in writing to the Administrative Agent a reduced Aggregate
          Commitment amount subject to a minimum reduction amount of $10,000,000
          (and in
          additional multiples of $10,000,000). Subject to any Special Redetermination
          permitted by this Section 2.6 and the provisions of this Section 2.6.3,
          such
          lesser amount designated by Unit will be the Aggregate Commitment until
          the next
          Scheduled Redetermination. The Administrative Agent and the Lenders stipulate
          that Unit has initially designated $275,000,000 as the Aggregate Commitment
          effective from the date of this Agreement. All parties hereto stipulate
          that the
          initial Borrowing Base is $425,000,000 as of the effective date of this
          Agreement.

         

        2.6.4.  In
          addition to Scheduled Redeterminations, the Lenders or the Borrowing Base
          Required Lenders, as applicable, will be permitted to make a Special
          Redetermination of the Borrowing Base once between each Determination Date
          by
          notifying the Administrative Agent and Borrowers. Such Special Redetermination
          by the Lenders shall be in addition to any reduction of the Borrowing Base
          by
          the Required Lenders under Section 7.4(iv). 

         

        2.6.5.  In
          addition to Scheduled Redeterminations, Borrowers will be permitted to
          request a
          Special Redetermination of the Borrowing Base (i) once between each
          Determination Date and (ii) following the consummation of the closing of
          any
          Acquisition by any Borrower permitted by this Agreement and for an amount
          equal
          to or greater than $40,000,000. Such request, including the amount requested,
          will be submitted in writing to the Administrative Agent and, at the time
          of
          such request, Unit will deliver to Administrative Agent and each Lender,
          any
          information they may reasonably request in connection with the request
          for a
          Special Redetermination. 

         

        
          
            19

          

          
            
            

            
            

          

          
            
            

          

        

        2.6.6.  If
          at any
          time, the Aggregate Outstanding Credit Exposure exceeds the lesser of the
          Borrowing Base or the Aggregate Commitment (a "Deficiency") because of
          a
          reduction in the Borrowing Base due to or resulting from a redetermination
          in
          accordance with this Section 2.6 (excluding Section 2.6.7 hereof),
          Administrative Agent may notify Unit in writing of the Deficiency and within
          ten
          (10) days from the date of such deficiency notice, Unit will elect one
          of the
          following options: 

         

        (a)  Make
          a
          prepayment on the Notes in an amount sufficient to reduce the aggregate
          unpaid
          principal balance of the Notes by an amount equal to or more than the amount
          of
          such Deficiency; or

         

        (b)  Dedicate
          to this Agreement other Oil and Gas Properties or assets not then included
          in
          the Borrowing Base determinations in form and substance satisfactory to
          the
          Required Lenders and the Administrative Agent as security and collateral
          for the
          Outstanding Credit Exposure and the Commitments (and all other Obligations),
          provided that such Oil and Gas Properties are acceptable to the Required
          Lenders
          and are of a value, as determined by the Administrative Agent and the Required
          Lenders, that the Aggregate Outstanding Credit Exposure does not exceed
          the
          Borrowing Base (as adjusted to include the values of the Oil and Gas
          Properties); or

         

        (c)  Commence
          monthly principal payments each equal to the amount of the Deficiency divided
          by
          the number of whole calendar months between date of the Deficiency notice
          and
          the next semi-annual Scheduled Redetermination.

         

        If
          Unit
          elects to (i) make a prepayment on the Notes under clause (a) or (ii) commence
          monthly principal payments under clause (c), such prepayment will be due
          within
          twenty (20) days after the date of Unit's timely election. The prepayment
          or
          monthly principal payments will be applied in reduction of the principal
          balance
          of the Notes. If Unit elects to commit Oil and Gas Properties under clause
          (b)
          above, the Borrowers will provide the Administrative Agent with descriptions
          of
          Oil and Gas Properties (together with any current valuations and engineering
          reports applicable thereto which may be requested by the Administrative
          Agent)
          and will execute, acknowledge and deliver to the Administrative Agent any
          security agreements or pledges within thirty (30) days after the documents
          are
          tendered to the Borrowers by the Administrative Agent for
          execution.

         

        2.6.7. The
          Borrowing Base will be automatically reduced if and to the extent Borrower
          issues or incurs Indebtedness as follows: (i) a dollar ($1.00) for dollar
          ($1.00) reduction if such Indebtedness is on a pari
          passu
          basis
          with the Obligations and (ii) up to an amount equal to a twenty seven cent
          ($0.27) reduction for each one dollar ($1.00) amount of expressly subordinated
          debt (including subordinated debt convertible to equity in Unit) so long
          as such
          subordinated debt is (x) in form, scope and content reasonably acceptable
          to the
          Administrative Agent and the Required Lenders, and (y) in compliance with
          the
          limitations of Section 7.2(ix). 

         

        
          
            20

          

          
            
            

            
            

          

          
            
            

          

        

        2.7  Minimum
          Amount of Each Advance.
          Each
          Eurodollar Advance will be in the minimum amount of $2,000,000 (and in
          additional multiples of $1,000,000), and each Floating Rate Advance will
          be in
          the minimum amount of $200,000 (and in additional multiples of $100,000),
          provided, that any Floating Rate Advance may be in the amount of the Available
          Aggregate Commitment. 

         

        2.8  Principal
          Payments.

         

        (a)  Optional
          Principal Payments.
          The
          Borrowers may from time to time pay, without penalty or premium, all outstanding
          Floating Rate Advances, or, in a minimum aggregate amount of $100,000 or
          any
          multiple of $100,000 in excess thereof, any portion of the outstanding
          Floating
          Rate Advances upon notice to the Administrative Agent . The Borrowers may
          from
          time to time pay, subject to the payment of any funding indemnification
          amounts
          required by Section 3.5 but without penalty or premium, all outstanding
          Eurodollar Advances, or, in a minimum aggregate amount of $2,000,000 or
          any
          integral multiple of $1,000,000 in excess thereof, any portion of the
          outstanding Eurodollar Advances upon three (3) Business Days' prior notice
          to
          the Administrative Agent.

         

        (b)  Mandatory
          Principal Payments.
          If at
          any time a Deficiency occurs as a result of the sale or disposition of
          any
          Borrowing Base Properties or pursuant to Section 2.6.7 (as opposed to a
          Deficiency subject to the provisions of Section 2.6.6 hereof), Borrowers
          will
          within 30 days after Administrative Agent gives notice of such fact to
          Borrowers
          to prepay the principal of the Loans in an aggregate amount at least equal
          to
          such Deficiency (or, if the Loans have been paid in full, deposit with
          the
          Administrative Agent the amount required to eliminate the Deficiency) together
          with interest during the period of such Deficiency at the Prime Rate per
          annum
          plus fifty basis points (0.50%) as to Floating Rate Advances or Eurodollar
          Rate
          plus two hundred twenty-five basis points (2.25%) as to Eurodollar Rate
          Loans
          per annum as to Eurodollar Rate Advances. Each payment of principal under
          this
          Section 2.8(b) will be accompanied by all interest then accrued and unpaid
          on
          the principal so prepaid. Any principal or interest prepaid pursuant to
          this
          section will be in addition to, and not in lieu of, all payments otherwise
          required to be paid under the Loan Documents at the time of such
          prepayment.

         

        2.9  Method
          of Selecting Loan Types and Interest Periods for New Advances.
          Unit
          will select the type of Advance and, in the case of each Eurodollar Advance,
          the
          Interest Period applicable thereto from time to time. Unit will give the
          Administrative Agent irrevocable notice (a "Borrowing Notice") not later
          than
          10:00 a.m. (Tulsa time) on the same Business Day as the Borrowing Date
          of each
          Floating Rate Advance and three Business Days before the Borrowing Date
          for each
          Eurodollar Advance, specifying:

         

        (i)
           the
          Borrowing Date, which will be a Business Day, of such Advance,

         

        (ii)
           the
          aggregate amount of such Advance,

         

        
          
            21

          

          
            
            

            
            

          

          
            
            

          

        

        (iii)
           the
          type
          (Floating Rate or Eurodollar) of Advance selected, and

         

        (iv)
           in
          the
          case of each Eurodollar Advance, the Interest Period applicable
          thereto.

         

        Not
          later
          than 1:00 p. m. (Tulsa, Oklahoma time) on each Borrowing Date, each Lender
          will
          make available its Loan or Loans in funds immediately available in Tulsa
          to the
          Administrative Agent at its address specified pursuant to Article XV. The
          Administrative Agent will make the funds so received from the Lenders available
          to the Borrowers at the Administrative Agent's aforesaid address.

         

        2.10  Conversion
          and Continuation of Outstanding Advances.
          Floating Rate Advances will continue as Floating Rate Advances unless and
          until
          such Floating Rate Advances are converted into Eurodollar Advances pursuant
          to
          this Section 2.10 or are repaid in accordance with Section 2.8. Each Eurodollar
          Advance will continue as a Eurodollar Advance until the end of the then
          applicable Interest Period therefor, at which time such Eurodollar Advance
          will
          be automatically converted into a Floating Rate Advance unless (x) such
          Eurodollar Advance is or was repaid in accordance with Section 2.8 or (y)
          Unit
          will have given the Administrative Agent a Conversion/Continuation Notice
          (as
          defined below) requesting that, at the end of such Interest Period, such
          Eurodollar Advance continue as a Eurodollar Advance for the same or another
          Interest Period. Subject to the terms of Section 2.7, Unit may elect from
          time
          to time to convert all or any part of a Floating Rate Advance into a Eurodollar
          Advance. Unit will give the Administrative Agent irrevocable notice (a
          "Conversion/Continuation Notice") of each conversion of a Floating Rate
          Advance
          into a Eurodollar Advance or continuation of a Eurodollar Advance not later
          than
          12:00 noon (Tulsa time) at least three Business Days prior to the date
          of the
          requested conversion or continuation, specifying:

         

        (i)
           the
          requested date, which will be a Business Day, of such conversion or
          continuation,

         

        (ii)
           the
          aggregate amount and type of the Advance (floating Rate Advance or Eurodollar
          Advance) which is to be converted or continued, and

         

        (iii)
           the
          amount of such Advance which is to be converted into or continued as a
          Eurodollar Advance and the duration of the Interest Period applicable
          thereto.

         

        2.11  Changes
          in Interest Rate.
          Each
          Floating Rate Advance will bear interest on the outstanding principal amount
          thereof, for each day from and including the date such Advance is made
          or is
          automatically converted from a Eurodollar Advance into a Floating Rate
          Advance
          pursuant to Section 2.10, to but excluding the date it is paid or is converted
          into a Eurodollar Advance pursuant to Section 2.10 hereof, at a rate per
          annum
          equal to the Floating Rate for such day. Changes in the rate of interest
          on that
          portion of any Advance maintained as a Floating Rate Advance will take
          effect
          simultaneously with each change in the Alternate Base Rate. Each Eurodollar
          Advance will bear interest on the outstanding principal amount thereof
          from and
          including the first day of the Interest Period applicable thereto to (but
          not
          including) the last day of such Interest Period at the interest rate determined
          by the Administrative Agent as applicable to such Eurodollar Advance based
          upon
          Unit's selections under Sections 2.9 and 2.10 and otherwise in accordance
          with
          the terms hereof. No Interest Period may end after the Facility Termination
          Date.

         

        
          
            22

          

          
            
            

            
            

          

          
            
            

          

        

        2.12  Rates
          Applicable After Default.
          Notwithstanding anything to the contrary contained in Section 2.9, 2.10
          or 2.11,
          during the continuance of a Default the Required Lenders may, at their
          option,
          by written notice to Unit, declare that no Advance may be made as, converted
          into or continued as a Eurodollar Advance. During the continuance of any
          Event
          of Default (i) each Eurodollar Advance will bear interest for the remainder
          of
          the applicable Interest Period at the rate otherwise applicable to such
          Interest
          Period plus an additional two hundred basis points (2.0%) per annum, (ii)
          each
          Floating Rate Advance will bear interest at a rate per annum equal to the
          Floating Rate in effect from time to time plus an additional two hundred
          basis
          points (2.0%) per annum and (iii) the LC Fee will be increased by an additional
          2% per annum, provided that, during the continuance of a Default under
          Section
          10.6 or 10.7, the interest rates set forth in clauses (i) and (ii) above
          and the
          increase in the LC Fee set forth in clause (iii) above will be applicable
          to all
          Credit Extensions without any election, notice or other action on the part
          of
          the Administrative Agent or any Lender. 

         

        2.13  Method
          of Payment.
          All
          payments of the Obligations hereunder will be made, without setoff, deduction,
          or counterclaim, in immediately available funds to the Administrative Agent
          at
          the Administrative Agent's address specified pursuant to Section 15.1,
          or at any
          other banking address of the Administrative Agent specified in writing
          by the
          Administrative Agent to Unit, by 12:00 noon (local Tulsa time) on the date
          when
          due and will (except in the case of Reimbursement Obligations for which
          the LC
          Issuer has not been fully indemnified by the Lenders, or as otherwise
          specifically required hereunder) be applied ratably by the Administrative
          Agent
          among the Lenders. Each payment delivered to the Administrative Agent for
          the
          account of any Lender will be delivered promptly by the Administrative
          Agent to
          such Lender in the same type of funds that the Administrative Agent received
          at
          its address specified pursuant to Section 15.1 or at any banking address
          specified in a notice received by the Administrative Agent from such Lender.
          The
          Administrative Agent is hereby authorized to charge the account of the
          Borrowers
          (other than any Excluded Account) maintained with BOk for each payment
          of
          principal, interest, Reimbursement Obligations and fees as it becomes due
          hereunder. Each reference to the Administrative Agent in this Section 2.13
          will
          also be deemed to refer, and will apply equally, to the LC Issuer, in the
          case
          of payments required to be made by the Borrowers to the LC Issuer pursuant
          to
          Section 2.19.

         

        All
          payments applied to principal or interest on any Note will be applied first
          to
          any interest then due and payable, then to principal then due and payable,
          and
          last to any prepayment of principal and interest in compliance with Section
          2.8.
          All distributions of amounts described in any of subsections (b) or (c)
          above
          will be made by Administrative Agent pro rata to each Lender then owed
          Obligations described in such subsection in proportion to all amounts owed
          to
          Administrative Agent and all Lenders which are described in such subsection;
          provided that if any Lender then owes payments to LC Issuer for the purchase
          of
          a participation under Section 2.19.5 or to Administrative Agent under Section
          13.7, any amounts otherwise distributable under this section to such Lender
          will
          be deemed to belong to LC Issuer, or Administrative Agent, respectively,
          to the
          extent of such unpaid payments, and Administrative Agent will apply such
          amounts
          to make such unpaid payments rather than distribute such amounts to such
          Lender.

         

        
          
            23

          

          
            
            

            
            

          

          
            
            

          

        

        2.14  Evidence
          of Indebtedness.

         

        (i)
           Each
          Lender will maintain in accordance with its usual practice an account or
          accounts evidencing the indebtedness of the Borrowers to such Lender resulting
          from each Loan made by such Lender from time to time, including the amounts
          of
          principal and interest payable and paid to such Lender from time to time
          hereunder.

         

        (ii)
           The
          Administrative Agent will also maintain accounts in which it will record
          (a) the
          amount of each Loan made hereunder, the type thereof and the Interest Period
          with respect thereto, (b) the amount of any principal or interest due and
          payable or to become due and payable from the Borrowers to each Lender
          hereunder, (c) the original stated amount of each LC and the amount of
          LC
          Obligations outstanding at any time, and (d) the amount of any sum received
          by
          the Administrative Agent hereunder from the Borrowers and each Lender's
          share
          thereof.

         

        (iii)
           The
          entries maintained in the accounts maintained pursuant to paragraphs (i)
          and
          (ii) above will be prima facie evidence of the existence and amounts of
          the
          Obligations therein recorded; provided, however, that the failure of the
          Administrative Agent or any Lender to maintain such accounts or any error
          therein will not in any manner affect the obligation of the Borrowers to
          repay
          the Obligations in accordance with their terms.

         

        (iv)
           Each
          Lender's Loans and interest therein will at all times be evidenced by a
          promissory note in the form of Exhibit A hereto (each a "Note") payable
          to the
          order of such Lender. 

         

        2.15  Telephonic
          Notices.
          The
          Borrowers hereby authorize the Lenders and the Administrative Agent to
          extend,
          convert or continue Advances, effect selections of types of Advances and
          to
          transfer funds based on telephonic notices made by any person or persons
          the
          Administrative Agent or any Lender in good faith believes to be acting
          on behalf
          of the Borrowers, it being understood that the foregoing authorization
          is
          specifically intended to allow Borrowing Notices and Conversion/Continuation
          Notices to be given telephonically. Unit agrees to deliver promptly to
          the
          Administrative Agent a written confirmation, if such confirmation is requested
          by the Administrative Agent or any Lender, of each telephonic notice signed
          by
          an Authorized Officer. If the written confirmation differs in any material
          respect from the action taken by the Administrative Agent and the Lenders,
          the
          records of the Administrative Agent and the Lenders will govern absent
          manifest
          error.

         

        2.16  Payment
          Date.
          Interest accrued on each Floating Rate Advance will be payable on the last
          day
          of each calendar month, commencing with the first such date to occur after
          the
          date hereof, on any date on which the Floating Rate Advance is prepaid,
          whether
          due to acceleration or otherwise, and at maturity. Interest accrued on
          that
          portion of the outstanding principal amount of any Floating Rate Advance
          converted into a Eurodollar Advance on a day other than a the foregoing
          monthly
          payment date will be payable on the date of conversion. Interest accrued
          on each
          one month (30 day), two months (60 days) or three months (90 days) Interest
          Period for Eurodollar Advance will be payable on the last day of its applicable
          Interest Period, on any date on which the Eurodollar Advance is prepaid,
          whether
          by 

         

        
          
            24

          

          
            
            

            
            

          

          
            
            
acceleration
            or otherwise, and at maturity. Interest accrued on each Eurodollar Advance
            having an Interest Period longer than three months (i.e., six months
            (180 days)
            Interest Period) will also be payable on the last day of each three-month
            interval during such Interest Period (each of the foregoing due dates
            for
            interest payments shall be deemed a "Payment Date"). Interest will be
            payable
            for the day an Advance is made but not for the day of any payment on
            the amount
            paid if payment is received prior to noon (local time) at the place of
            payment.
            If any payment of principal of or interest on an Advance will become
            due on a
            day which is not a Business Day, such payment will be made on the next
            succeeding Business Day and, in the case of a principal payment, such
            extension
            of time will be included in computing interest in connection with such
            payment.

        

         

        2.17  Notification
          of Advances, Interest Rates, and LC Requests.
          Promptly after receipt thereof, the Administrative Agent will notify each
          Lender
          of the contents of each Borrowing Notice, Conversion/Continuation Notice,
          and
          repayment notice received by it hereunder. Promptly after notice from the
          LC
          Issuer, the Administrative Agent will notify each Lender of the contents
          of each
          request for issuance of a LC thereunder. 

         

        2.18  Non-Receipt
          of Funds by the Administrative Agent.
          Unless
          Unit or a Lender, as the case may be, notifies the Administrative Agent
          prior to
          the date on which it is scheduled to make payment to the Administrative
          Agent of
          (i) in the case of a Lender, the proceeds of a Loan or (ii) in the case
          of the
          Borrowers, a payment of principal, interest or fees to the Administrative
          Agent
          for the account of the Lenders, that it does not intend to make such payment,
          the Administrative Agent may assume that such payment has been made. The
          Administrative Agent may, but will not be obligated to, make the amount
          of such
          payment available to the intended recipient in reliance upon such assumption.
          If
          such Lender or the Borrowers, as the case may be, have not in fact made
          such
          payment to the Administrative Agent, the recipient of such payment will,
          on
          demand by the Administrative Agent, repay to the Administrative Agent the
          amount
          so made available together with interest thereon in respect of each day
          during
          the period commencing on the date such amount was so made available by
          the
          Administrative Agent until the date the Administrative Agent recovers such
          amount at a rate per annum equal to (x) in the case of payment by a Lender,
          the
          Federal Funds Effective Rate for such day for the first three days and,
          thereafter, the interest rate applicable to the relevant Loan or (y) in
          the case
          of payment by the Borrowers, the interest rate applicable to the relevant
          Loan.

         

        2.19  Letters
          of Credit.

         

        2.19.1.  Issuance.
          The LC
          Issuer hereby agrees, on the terms and conditions set forth in this Agreement,
          to issue standby Letters of Credit (each, a "LC") and to renew, extend,
          increase, decrease or otherwise modify each LC ("Modify," and each such
          action a
          "Modification"), from time to time from and including the date of this
          Agreement
          and prior to the Facility Termination Date upon the request of Unit; provided
          that immediately after each such LC is issued or Modified, (i) the aggregate
          amount of the outstanding LC Obligations will not exceed the LC Sublimit
          at any
          time and (ii) the Aggregate Outstanding Credit Exposure will not exceed
          the
          Aggregate Commitment. No LC will have an expiry date later than one year
          after
          the issuance thereof; provided that if such expiry date is after the fifth
          Business Day prior to the Facility Termination Date, Borrowers will deposit
          with
          the Administrative Agent on such date immediately available funds in an
          amount
          equal to or greater than the undrawn amount of such LC.

         

        
          
            25

          

          
            
            

            
            

          

          
            
            

          

        

        2.19.2.  Participations.
          Upon
          the issuance or Modification by the LC Issuer of a LC in accordance with
          this
          Section 2.19, the LC Issuer will be deemed, without further action by any
          party
          hereto, to have unconditionally and irrevocably sold to each Lender, and
          each
          Lender will be deemed, without further action by any party hereto, to have
          unconditionally and irrevocably purchased from the LC Issuer, a participation
          in
          such LC (and each Modification thereof) and the related LC Obligations
          in
          proportion to its Pro Rata Share.

         

        2.19.3.  Notice.
          Subject
          to Section 2.19.1, Unit will give the LC Issuer notice prior to 10:00 a.m.
          (Tulsa time) at least one Business Day prior to the proposed date of issuance
          or
          Modification of each LC, specifying the beneficiary, the proposed date
          of
          issuance (or Modification) and the expiry date of such LC, and describing
          the
          proposed terms of such LC and the nature of the transactions proposed to
          be
          supported thereby. Upon receipt of such notice, the LC Issuer will promptly
          notify the Administrative Agent, and the Administrative Agent will promptly
          notify each Lender, of the contents thereof and of the amount of such Lender's
          participation in such proposed LC. The issuance or Modification by the
          LC Issuer
          of any LC will, in addition to the conditions precedent set forth in Article
          IV
          (the satisfaction of which the LC Issuer will have no duty to ascertain),
          be
          subject to the conditions precedent that such LC will be satisfactory to
          the LC
          Issuer and that the Borrowers will have executed and delivered such LC
          Application agreement and/or such other instruments and agreements relating
          to
          such LC as the LC Issuer will have reasonably requested (each, a "LC
          Application"). In the event of any conflict between the terms of this Agreement
          and the terms of any LC Application, the terms of this Agreement will
          control.

         

        2.19.4.  LC
          Fees.
          The
          Borrowers will pay to the Administrative Agent, for the account of the
          Lenders
          ratably in accordance with their respective Pro Rata Shares, a letter of
          credit
          fee at the time of issuance, calculated at an amount equal to the greater
          of
          $500.00 or a per annum rate equal to the Applicable Margin for Eurodollar
          Loans
          on the stated amount of such LC (each such fee described in this sentence
          an "LC
          Fee"). The Borrowers will also pay to the LC Issuer for its own account
          at the
          time of issuance of each LC, a fronting fee in an amount equal to 0.125%
          per
          annum of the initial stated amount, and documentary and processing charges
          in
          connection with the issuance or Modification of and draws under LCs in
          accordance with the LC Issuer's standard schedule for such charges as in
          effect
          from time to time.

         

        2.19.5.  Administration;
          Reimbursement by Lenders.
          Upon
          receipt from the beneficiary of any LC of any demand for payment under
          such LC,
          the LC Issuer will notify the Administrative Agent and the Administrative
          Agent
          will promptly notify the Borrowers and each other Lender as to the amount
          to be
          paid by the LC Issuer as a result of such demand and the proposed payment
          date
          (the "LC Payment Date"). The responsibility of the LC Issuer to the Borrowers
          and each Lender will be only to determine that the documents (including
          each
          demand for payment) delivered under each LC in connection with such presentment
          will be in conformity in all material respects with such LC. In the absence
          of
          any gross negligence or willful misconduct by the LC Issuer, each Lender
          will be
          unconditionally and irrevocably liable without regard to the occurrence
          of any
          Default or any condition precedent whatsoever, to reimburse the LC Issuer
          on
          demand for (i) such Lender's 

         

        
          
            26

          

          
            
            

            
            

          

          
            
            
Pro
            Rata
            Share of the amount of each payment made by the LC Issuer under each
            LC to the
            extent such amount is not reimbursed by the Borrowers pursuant to Section
            2.19.6
            below, plus (ii) interest on the foregoing amount to be reimbursed by
            such
            Lender, for each day from the date of the LC Issuer's demand for such
            reimbursement (or, if such demand is made after 11:00 a.m. (Tulsa time)
            on such
            date, from the next succeeding Business Day) to the date on which such
            Lender
            pays the amount to be reimbursed by it, at a rate of interest per annum
            equal to
            the Federal Funds Effective Rate for the first three days and, thereafter,
            at a
            rate of interest equal to the rate applicable to Floating Rate
            Advances.

        

         

        2.19.6.  Reimbursement
          by Borrowers.
          The
          Borrowers will be irrevocably and unconditionally obligated to reimburse
          the LC
          Issuer on or before the applicable LC Payment Date for any amounts to be
          paid by
          the LC Issuer upon any drawing under any LC, without presentment, demand,
          protest or other formalities of any kind; provided that neither the Borrowers
          nor any Lender will hereby be precluded from asserting any claim for direct
          (but
          not consequential) damages suffered by the Borrowers or such Lender to
          the
          extent, but only to the extent, caused by (i) the willful misconduct or
          gross
          negligence of the LC Issuer in determining whether a request presented
          under any
          LC issued by it complied with the terms of such LC or (ii) the LC Issuer's
          failure to pay under any LC issued by it after the presentation to it of
          a
          request strictly complying with the terms and conditions of such LC. All
          such
          amounts paid by the LC Issuer and remaining unpaid by the Borrowers will
          bear
          interest, payable on demand, for each day until paid at a rate per annum
          equal
          to (x) the rate applicable to Floating Rate Advances for such day if such
          day
          falls on or before the applicable LC Payment Date and (y) the sum of two
          hundred
          basis points (2.0%) plus the rate applicable to Floating Rate Advances
          for such
          day if such day falls after such LC Payment Date. The LC Issuer will pay
          to each
          Lender ratably in accordance with its Pro Rata Share all amounts received
          by it
          from the Borrowers for application in payment, in whole or in part, of
          the
          Reimbursement Obligation in respect of any LC issued by the LC Issuer,
          but only
          to the extent such Lender has made payment to the LC Issuer in respect
          of such
          LC pursuant to Section 2.19.5. Subject to the terms and conditions of this
          Agreement, the Borrowers may request an Advance hereunder for the purpose
          of
          satisfying any Reimbursement Obligation. 

         

        2.19.7.  Obligations
          Absolute.
          The
          Borrowers' obligations under this Section 2.19 will be absolute and
          unconditional under any and all circumstances and irrespective of any setoff,
          counterclaim or defense to payment which the Borrowers may have or have
          had
          against the LC Issuer, any Lender or any beneficiary of a LC. The Borrowers
          further agree with the LC Issuer and the Lenders that the LC Issuer and
          the
          Lenders will not be responsible for, and the Borrowers' Reimbursement Obligation
          in respect of any LC will not be affected by, among other things, the validity
          or genuineness of documents or of any endorsements thereon, even if such
          documents should in fact prove to be in any or all respects invalid, fraudulent
          or forged, or any dispute between or among the Borrowers, any of their
          Affiliates, the beneficiary of any LC or any financing institution or other
          party to whom any LC may be transferred or any claims or defenses whatsoever
          of
          the Borrowers or of any of their Affiliates against the beneficiary of
          any LC or
          any such transferee. The LC Issuer will not be liable for any error, omission,
          interruption or delay in transmission, dispatch or delivery of any message
          or
          advice, however transmitted, in connection with any LC. The Borrowers agree
          that
          any action taken 

         

        
          
            27

          

          
            
            

            
            

          

          
            
            
or
            omitted by the LC Issuer or any Lender under or in connection with each
            LC and
            the related drafts and documents, if done without gross negligence or
            willful
            misconduct, will be binding upon the Borrowers and will not put the LC
            Issuer or
            any Lender under any liability to the Borrowers. Nothing in this Section
            2.19.7
            is intended to limit the right of the Borrowers to make a claim against
            the LC
            Issuer for damages as contemplated by the proviso to the first sentence
            of
            Section 2.19.6.

        

         

        2.19.8.  Actions
          of LC Issuer.
          The LC
          Issuer will be entitled to rely, and will be fully protected in relying,
          upon
          any LC, draft, writing, resolution, notice, consent, certificate, affidavit,
          letter, cablegram, telegram, telecopy, telex or teletype message, statement,
          order or other document believed by it to be genuine and correct and to
          have
          been signed, sent or made by the proper Person or Persons, and upon advice
          and
          statements of legal counsel, independent accountants and other experts
          selected
          by the LC Issuer. The LC Issuer will be fully justified in failing or refusing
          to take any action under this Agreement unless it will first have received
          such
          advice or concurrence of the Required Lenders as it reasonably deems appropriate
          or it will first be indemnified to its reasonable satisfaction by the Lenders
          against any and all liability and expense which may be incurred by it by
          reason
          of taking or continuing to take any such action. Notwithstanding any other
          provision of this Section 2.19, the LC Issuer will in all cases be fully
          protected in acting, or in refraining from acting, under this Agreement
          in
          accordance with a request of the Required Lenders, and such request and
          any
          action taken or failure to act pursuant thereto will be binding upon the
          Lenders
          and any future holders of a participation in any LC.

         

        2.19.9.  Indemnification.
          The
          Borrowers will indemnify and hold harmless each Lender, the LC Issuer and
          the
          Administrative Agent, and their respective directors, officers, Administrative
          Agents and employees from and against any and all claims and damages, losses,
          liabilities, costs or expenses which such Lender, the LC Issuer or the
          Administrative Agent may incur (or which may be claimed against such Lender,
          the
          LC Issuer or the Administrative Agent by any Person whatsoever) by reason
          of or
          in connection with the issuance, execution and delivery or transfer of
          or
          payment or failure to pay under any LC or any actual or proposed use of
          any LC,
          including, without limitation, any claims, damages, losses, liabilities,
          costs
          or expenses which the LC Issuer may incur by reason of or in connection
          with (i)
          the failure of any other Lender to fulfill or comply with its obligations
          to the
          LC Issuer hereunder (but nothing herein contained will affect any rights
          the
          Borrowers may have against any defaulting Lender) or (ii) by reason of
          or on
          account of the LC Issuer issuing any LC which specifies that the term
          "Beneficiary" included therein includes any successor by operation of law
          of the
          named Beneficiary, but which LC does not require that any drawing by any
          such
          successor Beneficiary be accompanied by a copy of a legal document, satisfactory
          to the LC Issuer, evidencing the appointment of such successor Beneficiary;
          provided that the Borrowers will not be required to indemnify any Lender,
          the LC
          Issuer or the Administrative Agent for any claims, damages, losses, liabilities,
          costs or expenses to the extent, but only to the extent, caused by (x)
          the
          willful misconduct or gross negligence of the LC Issuer in determining
          whether a
          request presented under any LC complied with the terms of such LC or (y)
          

         

        
          
            28

          

          
            
            

            
            

          

          
            
            
the
            LC
            Issuer's failure to pay under any LC after the presentation to it of
            a request
            strictly complying with the terms and conditions of such LC. Nothing
            in this
            Section 2.19.9 is intended to limit the obligations of the Borrowers
            under any
            other provision of this Agreement. 

        

         

        2.19.10.  Lenders'
          Indemnification.
          Each
          Lender will, ratably in accordance with its Pro Rata Share, indemnify the
          LC
          Issuer, its Affiliates and their respective directors, officers, Administrative
          Agents and employees (to the extent not reimbursed by the Borrowers) against
          any
          cost, expense (including reasonable counsel fees and disbursements), claim,
          demand, action, loss or liability (except such as result from such indemnitees'
          gross negligence or willful misconduct or the LC Issuer's failure to pay
          under
          any LC after the presentation to it of a request strictly complying with
          the
          terms and conditions of the LC) that such indemnitees may suffer or incur
          in
          connection with this Section 2.19 or any action taken or omitted by such
          indemnitees hereunder.

         

        2.20  Additional
          Agency Fees.
          Borrowers will pay certain additional fees to the Administrative Agent
          in the
          amounts and on the terms described in the Agent Fee Letter.

         

        2.21  Loan
          Purposes.
          Advances may be requested by Unit on behalf of the Borrowers for (i) refinancing
          in full any Existing Indebtedness and extinguishment of the commitments
          issued
          pursuant to the Existing Credit Agreement, (ii) general working capital
          requirements for (a) exploration, development, production and acquisition
          of Oil
          and Gas Properties, (b) contract drilling services, and (c) gas gathering
          systems, gas processing plants and other midstream assets, (iii) issuance
          of
          standby Letters of Credit, and (iv) general corporate purposes of the Borrowers.
          

         

        ARTICLE
          III

        YIELD
          PROTECTION; TAXES

         

        3.1  Yield
          Protection.
          If, on
          or after the date of this Agreement, the adoption of any law or any governmental
          or quasi-governmental rule, regulation, policy, guideline or directive
          (whether
          or not having the force of law), or any change in the interpretation or
          administration thereof by any governmental or quasi-governmental authority,
          central bank or comparable agency charged with the interpretation or
          administration thereof, or compliance by any Lender or applicable banking
          address or the LC Issuer with any request or directive (whether or not
          having
          the force of law) of any such authority, central bank or comparable
          agency:

         

        (i)
           subjects
          any Lender or the LC Issuer to any Taxes, or changes the basis of taxation
          of
          payments (other than Excluded Taxes) to any Lender or the LC Issuer regarding
          its Eurodollar Loans or participations in Eurodollar Advances, or

         

        (ii)
           imposes
          or increases or deems applicable any reserve, assessment, insurance charge,
          special deposit or similar requirement against assets of, deposits with
          or for
          the account of, or credit extended by, any Lender or the LC Issuer (other
          than
          reserves and assessments taken into account in determining the interest
          rate
          applicable to Eurodollar Advances), or

         

        (iii)
           imposes
          any other condition the result of which is to increase the cost to any
          Lender,
          the interbank eurocurrency deposit market or the LC Issuer of making, funding
          or
          maintaining its Eurodollar Loans, 

         

        
          
            29

          

          
            
            

            
            

          

          
            
            
or
            of
            issuing or participating in LCs, or reduces any amount receivable by
            any Lender,
            the interbank eurocurrency deposit market or the LC Issuer in connection
            with
            its Eurodollar Loans, LCs or participations therein, or requires any
            Lender, the
            interbank eurocurrency deposit market or the LC Issuer to make any payment
            calculated by reference to the amount of Eurodollar Loans, LCs or participations
            therein held or interest or LC Fees received by it, by an amount deemed
            material
            by such Lender or the LC Issuer as the case may be and the result of
            any of the
            foregoing is to increase the cost to such Lender or the LC Issuer, as
            the case
            may be, of making or maintaining its Eurodollar Loans or Commitment or
            of
            issuing or participating in LCs or to reduce the return received by such
            Lender,
            the interbank eurocurrency deposit market or the LC Issuer, as the case
            may be,
            in connection with such Eurodollar Loans, Commitment, LCs or participations
            therein, 

        

         

        then,
          within 15 days of demand by the Administrative Agent or the LC Issuer,
          as the
          case may be, the Borrowers will pay the Administrative Agent for the account
          of
          such Lender or the LC Issuer, as the case may be, such additional amount
          or
          amounts as will compensate such Lender or the LC Issuer, as the case may
          be, for
          such increased cost or reduction in amount received.

         

        3.2  Changes
          in Capital Adequacy Regulations.
          If a
          Lender or the LC Issuer determines, in good faith, the amount of capital
          required or expected to be maintained by such Lender or the LC Issuer,
          or the LC
          Issuer, or any corporation controlling such Lender or the LC Issuer is
          increased
          as a result of a Change, then, within 15 days of demand by such Lender
          or the LC
          Issuer, the Borrowers will pay such Lender or the LC Issuer the amount
          necessary
          to compensate for any shortfall in the rate of return on the portion of
          such
          increased capital which such Lender or the LC Issuer determined is attributable
          to this Agreement, its Outstanding Credit Exposure or its Commitment to
          make
          Loans and issue or participate in LCs, as the case may be, hereunder (after
          taking into account such Lender's or the LC Issuer's policies as to capital
          adequacy). "Change" means (i) any change after the date of this Agreement
          in the
          Risk-Based Capital Guidelines or (ii) any adoption of or change in any
          other
          law, governmental or quasi-governmental rule, regulation, policy, guideline,
          interpretation, or directive (whether or not having the force of law) after
          the
          date of this Agreement which affects the amount of capital required or
          expected
          to be maintained by any Lender or the LC Issuer or any corporation controlling
          any Lender or the LC Issuer. "Risk-Based Capital Guidelines" means (i)
          the
          risk-based capital guidelines in effect in the United States on the date
          of this
          Agreement, including transition rules, and (ii) the corresponding capital
          regulations promulgated by regulatory authorities outside the United States
          implementing the July 1988 report of the Basle Committee on Banking Regulation
          and Supervisory Practices Entitled "International Convergence of Capital
          Measurements and Capital Standards," including transition rules, and any
          amendments to such regulations adopted prior to the date of this
          Agreement.

         

        3.3  Taxes.

         

        (i)
           All
          payments by the Borrowers to or for the account of any Lender, the LC Issuer
          or
          the Administrative Agent hereunder or under any Note or LC Application
          will be
          made free and clear of and without deduction for any and all Taxes. If
          the
          Borrowers are required by law to deduct any Taxes from any payment to a
          Lender,
          the LC Issuer or the Administrative Agent, to the extent not prohibited
          by
          applicable law, 

         

        
          
            30

          

          
            
            

            
            

          

          
            
            

          

           

          (a)
            the
            payment will be increased so that after making all required deductions
            (including deductions applicable to payments under this Section 3.3)
            such
            Lender, the LC Issuer or the Administrative Agent (as the case may be)
            receives
            an amount equal to the payment it would have received had no deductions
            been
            made, (b) the Borrowers will make such deductions, (c) the Borrowers
            will pay
            the full amount deducted to the relevant authority in accordance with
            applicable
            law and (d) the Borrowers will furnish to the Administrative Agent a
            copy of a
            receipt evidencing payment within 30 days after the payment is
            made.

        

         

        (ii)
           In addition, the Borrowers hereby agree to pay any present or future stamp
          or documentary taxes and any other excise or property taxes, charges or
          similar
          levies which arise from any payment made under this Agreement or under
          any Note
          or LC Application or from the execution or delivery of, or otherwise with
          respect to, this Agreement or any Note or LC Application ("Other
          Taxes").

         

        (iii)
           The
          Borrowers hereby agree to indemnify the Administrative Agent, the LC Issuer
          and
          each Lender for the full amount of Taxes or Other Taxes (including, without
          limitation, any Taxes or Other Taxes imposed on payments under this Section
          3.3)
          paid by the Administrative Agent, the LC Issuer or such Lender and any
          liability
          (including penalties, interest and expenses) arising therefrom or with
          respect
          thereto. Payments properly due under this indemnification will be made
          within 30
          days following the date the Administrative Agent, the LC Issuer or such
          Lender
          requests payment.

         

        (iv)
           If
          the
          U.S. Internal Revenue Service or any other governmental authority of the
          United
          States or any other country or any political subdivision thereof asserts
          a claim
          that the Agent did not properly withhold tax from payments to or for the
          account
          of any Lender (because the appropriate form was not delivered or properly
          completed, because such Lender failed to notify the Agent of a change in
          circumstances which rendered its exemption from withholding ineffective,
          or for
          any other reason), such Lender will indemnify the Agent fully for all amounts
          paid, directly or indirectly, by the Agent as tax, withholding therefor,
          or
          otherwise, including penalties and interest, and including taxes imposed
          by any
          jurisdiction on amounts payable to the Agent under this subsection, together
          with all costs and expenses related thereto (including attorneys fees and
          time
          charges of attorneys for the Agent, which attorneys may be employees of
          the
          Agent). The obligations of the Lenders under this Section 3.3(iv) will
          survive
          the payment of the Obligations and termination of this Agreement. Any liability
          under this subsection (iv) will not be a liability of the Borrowers

         

        3.4  Availability
          of Eurodollar Advances.
          If any
          Lender determines that maintenance of its Eurodollar Loans at a suitable
          banking
          location would violate any applicable law, rule, regulation, or directive,
          whether or not having the force of law, or if the Required Lenders determine
          that (i) deposits of a type and maturity appropriate to match fund Eurodollar
          Advances are not available or (ii) the interest rate applicable to Eurodollar
          Advances does not accurately reflect the cost of making or maintaining
          Eurodollar Advances, then the Administrative Agent will suspend the availability
          of Eurodollar Advances and require any affected Eurodollar Advances to
          be repaid
          or converted to Floating Rate Advances, subject to the payment of any funding
          indemnification amounts required by Section 3.5.

         

        
          
            31

          

          
            
            

            
            

          

          
            
            

          

        

        3.5  Funding
          Indemnification.
          If any
          payment of a Eurodollar Advance occurs on a date which is not the last
          day of
          the applicable Interest Period, whether because of acceleration, prepayment
          or
          otherwise, or a Eurodollar Advance is not made on the date specified by
          the
          Borrowers for any reason other than default by the Lenders, the Borrowers
          will
          indemnify each Lender for any resulting loss or cost incurred by
          it.

         

        3.6  Replacement
          Lenders.

         

        3.6.1.  If
          any
          Lender (i) has notified Unit and the Administrative Agent of the circumstances
          described in Sections 3.1 or 3.4, (ii) has required Unit to make payments
          for
          Taxes under Section 3.3, (iii) defaults in its obligations to fund advances
          hereunder or participate in LC Exposure, (iv) is a Non-Extending Lender
          pursuant
          to Section 3.7, or (v) objects to an increase in the Borrowing Base proposed
          by
          the Administrative Agent pursuant to the provisions of Section 2.6.2, then
          Unit
          may, at its sole cost, expense and effort, provided that no Event of Default
          then exists, unless such Lender has notified Unit and the Administrative
          Agent
          in writing that the circumstances giving rise to such notice, event or
          circumstance no longer apply or such Lender otherwise withdraws its request
          for
          such additional compensation or approves the proposed Borrowing Base increase
          tendered by the Administrative Agent, terminate, in whole but not in part,
          the
          Commitment of any Lender (other than the Administrative Agent) (in any
          such
          case, the "Terminated Lender") at any time within ninety (90) days of such
          Lender notification, upon ten (10) days' prior written notice to the Terminated
          Lender and the Administrative Agent (such notice referred to herein as
          a "Notice
          of Termination").

         

        3.6.2.  In
          order
          to effect the termination of the Commitment of the Terminated Lender, Unit
          shall: (i) obtain an agreement with one or more Lenders to increase their
          Commitment or Commitments and/or (ii) request any one or more other banking
          or
          lending institutions to become parties to this Agreement in place and instead
          of
          such Terminated Lender and agree to accept a Commitment or Commitments;
          provided, however, that such one or more other banking or lending institutions
          are reasonably acceptable to the Administrative Agent and become parties
          by
          executing an Assignment (the Lenders or other banking institutions that
          agree to
          accept in whole or in part the Commitment of the Terminated Lender being
          referred to herein as the "Replacement Lenders") without recourse from
          the
          Terminated Lender, such that the aggregate increased and/or accepted Commitments
          of the Replacement Lenders under clauses (i) and (ii) above equal the Commitment
          of the Terminated Lender.

         

        3.6.3.  The
          Notice of Termination shall include the name of the Terminated Lender,
          the date
          the termination will occur (the "Lender Termination Date"), and within
          twenty
          (20) days of the Notice of Termination, Unit shall designate in writing
          the
          Replacement Lender or Replacement Lenders to which the Terminated Lender
          will
          assign its Commitment and, if there will be more than one Replacement Lender,
          the portion of the Terminated Lender's Commitment to be assigned to each
          Replacement Lender.

         

        3.6.4.  On
          the
          Lender Termination Date, (i) the Terminated Lender shall by execution and
          delivery of an Assignment assign, without recourse, its Commitment and
          all of
          its interests, rights and 

         

        
          
            32

          

          
            
            

            
            

          

          
            
            
obligations
            under this Agreement and the related Loan Documents to the Replacement
            Lender or
            Replacement Lenders (pro rata, if there is more than one Replacement
            Lender, in
            proportion to the Pro Rata Share of the Terminated Lender's Commitment
            to be
            assigned to each Replacement Lender) indicated in the Notice of Termination
            and
            shall assign to the Replacement Lender or Replacement Lenders each of
            its Loans
            (if any) then outstanding and participation interests in Letters of Credit
            (if
            any) then outstanding pro rata as aforesaid), (ii) the Terminated Lender
            shall
            endorse its Note, payable without recourse, representation or warranty
            to the
            order of the Replacement Lender or Replacement Lenders (Pro Rata Share
            as
            aforesaid), (iii) the Replacement Lender or Replacement Lenders shall
            purchase
            the Note held by the Terminated Lender (pro rata as aforesaid) at a price
            equal
            to the unpaid principal amount thereof (including its participation in
            and Pro
            Rata Share of the LC Exposure) plus interest, facility fees, Commitment
            Fee and
            other fees accrued and unpaid to the Lender Termination Date, and (iv)
            the
            Replacement Lender or Replacement Lenders will thereupon (pro rata as
            aforesaid)
            succeed to and be substituted in all respects for the Terminated Lender
            with
            like effect as if becoming a Lender pursuant to the terms of Section
            14.6, and
            the Terminated Lender will have the rights and benefits of an assignor
            under
            Section 14.6. To the extent not in conflict, the terms of Section 14.6
            shall
            supplement the provisions of this Section 3.6.4. For each assignment
            made under
            this Section 3.6, the Replacement Lender shall pay to the Agent the processing
            fee provided for in Section 14.6. The Borrower will be responsible for
            the
            concurrent payment of any breakage costs associated with termination
            and
            Replacement Lenders, as set forth in Section 3.6.

        

         

        3.7  Extension
          of Maturity Date.

         

        3.7.1.  Requests
          for Extension.
          Unit
          may, by notice to the Administrative Agent (who shall promptly notify the
          Lenders) not earlier than eighteen (18) months and not later than fifteen
          (15)
          months prior to the stated Facility Termination Date then in effect hereunder
          (the "Existing Maturity Date"), request that each Lender extend such Lender's
          Facility Termination Date for an additional one (1) year period from the
          Existing Maturity Date; provided that, the Borrowers may request only two
          such
          extensions under this Agreement and Borrowers shall pay at the extension
          closing
          of such extension a reasonable extension fee, the amount of which shall
          be
          negotiated and agreed to by the Lenders and Unit. 

         

        3.7.2.  Lender
          Elections to Extend.
          Each
          Lender, acting in its sole and individual discretion, shall, by notice
          to the
          Administrative Agent given not later than the date (the "Notice Date")
          that is
          sixty (60) days after Unit has given notice in accordance with Section
          3.7.1,
          advise the Administrative Agent whether or not such Lender agrees to such
          extension (and each Lender that determines not to so extend its Facility
          Termination Date (a "Non Extending Lender") shall notify the Administrative
          Agent of such fact promptly after such determination (but in any event
          no later
          than the Notice Date) and any Lender that does not so advise the Administrative
          Agent on or before the Notice Date shall be deemed to be a Non Extending
          Lender.
          The election of any Lender to agree to such extension shall not obligate
          any
          other Lender to so agree.

         

        
          
            33

          

          
            
            

            
            

          

          
            
            

          

        

        3.7.3.  Notification
          by Administrative Agent.
          The
          Administrative Agent shall notify the Borrower of each Lender’s determination
          under this Section no later than the date seven (7) days after the Notice
          Date
          (or, if such date is not a Business Day, on the next succeeding Business
          Day).

         

        3.7.4.  Additional
          Commitment Lenders.
          The
          Borrower shall have the right on or before the Existing Maturity Date to
          replace
          each Non Extending Lender with, and add as "Lenders" under this Agreement
          in
          place thereof, one or more Replacement Lenders (each, an "Additional Commitment
          Lender") as provided in Section 3.6, each of which Additional Commitment
          Lenders
          shall have entered into an Assignment and Assumption pursuant to which
          such
          Additional Commitment Lender shall, effective as of the Existing Maturity
          Date,
          undertake a Commitment (and, if any such Additional Commitment Lender is
          already
          a Lender, its Commitment shall be in addition to such Lender’s Commitment
          hereunder on such date).

         

        3.7.5.  Minimum
          Extension Requirement.
          If (and
          only if) the total of the Commitments of the Lenders that have agreed so
          to
          extend their Facility Termination Date and the additional Commitments of
          the
          Additional Commitment Lenders shall be more than 50% of the aggregate amount
          of
          the Commitments in effect immediately prior to the Existing Maturity Date,
          then,
          effective as of the Existing Maturity Date, the Maturity Date of each Extending
          Lender and of each Additional Commitment Lender shall be extended to the
          date
          falling one year after the Existing Maturity Date (except that, if such
          date is
          not a Business Day, such Facility Termination Date as so extended shall
          be the
          next preceding Business Day) and each Additional Commitment Lender shall
          thereupon become a "Lender" for all purposes of this Agreement.

         

        3.7.6.  Conditions
          to Effectiveness of Extensions.
          Notwithstanding the foregoing, the extension of the Facility Termination
          Date
          pursuant to this Section shall not be effective with respect to any Lender
          unless:

         

        (i) no
          Default or Event of Default shall have occurred and be continuing on the
          date of
          such extension and after giving effect thereto;

         

        (ii) the
          representations and warranties contained in this Agreement are true and
          correct
          on and as of the date of such extension and after giving effect thereto,
          as
          though made on and as of such date (or, if any such representation or warranty
          is expressly stated to have been made as of a specific date, as of such
          specific
          date); and

         

        (iii) on
          the
          Facility Termination Date of each Non-Extending Lender, the Borrower shall
          prepay any Obligations outstanding on such date to such Non-Extending Lender
          (and pay any additional amounts required pursuant to Section 3.1).

         

        3.7.7.  Conflicting
          Provisions.
          This
          Section shall supersede any provisions in Section 15.3 to the
          contrary.

         

        
          
            34

          

          
            
            

            
            

          

          
            
            

          

        

        ARTICLE
          IV

        CONDITIONS
          PRECEDENT

         

        4.1  Initial
          Credit Extension.
          The
          Lenders will not be required to make the initial Credit Extension hereunder
          unless:

         

        4.1.1.  Unit
          has
          furnished to the Administrative Agent at its main banking offices in Tulsa,
          Oklahoma, each of the following, duly executed by the applicable Credit
          Parties
          and delivered in form, substance and date satisfactory to the Administrative
          Agent, with sufficient copies for all of the Lenders:

         

        (i)
           Copies
          of
          the certificate of incorporation or certificate of organization or formation,
          as
          applicable, of each of the Credit Parties, together with all amendments,
          and a
          certificate of good standing, each certified by the appropriate governmental
          officer in their respective jurisdiction of organization.

         

        (ii) Copies,
          certified by the Secretary or Assistant Secretary of the Credit Parties,
          of
          their respective by-laws or operating agreement or regulations, as applicable,
          and of their respective Board of Directors' or members/managers' resolutions
          and
          of resolutions or actions of any other body authorizing the execution of
          the
          Loan Documents to which each Borrower is a party.

         

        (iii)
           An
          incumbency certificate, executed by the Secretary or Assistant Secretary
          of the
          Credit Parties, which will identify by name and title and bear the signatures
          of
          the Authorized Officers and any other officers of the Borrower authorized
          to
          sign the Loan Documents to which such Borrower is a party, with the
          Administrative Agent and the Lenders being entitled to rely on such certificate
          until informed of any change in writing by such Borrower.

         

        (iv)
           A
          certificate, signed by the chief financial officer of Unit (on behalf of
          all of
          the Credit Parties), stating that on the initial Credit Extension Date
          no
          Default has occurred and is continuing, that all representations and warranties
          in the Loan Documents are true and correct and that no Material Adverse
          Effect
          has occurred.

         

        (v)
           A
          favorable written closing opinion of outside counsel to the Borrowers,
          addressed
          to the Administrative Agent and the Lenders in form, scope and substance
          satisfactory to the Administrative Agent.

         

        (vi) This
          Agreement and a Note payable to the order of each Lender and, the Subsidiary
          Guaranty by any Material Subsidiary substantially in the form of Exhibit
          E of
          this Agreement.

         

        (vii)
           Arrangements
          satisfactory to the Administrative Agent, the LC Issuer and any applicable
          beneficiary concerning payment in full of any Indebtedness owing under
          the
          Existing Credit Agreement to the Existing Lenders, including all interest
          thereon and that any unexpired letters of credit issued thereunder have
          been
          terminated or otherwise collateralized to the satisfaction of the 

         

        
          
            35

          

          
            
            

            
            

          

          
            
            

          

          Administrative
            Agent and the LC Issuer under the Existing Credit Agreement, including
            evidence
            satisfactory to Unit and the Administrative Agent of the cancellation
            of the
            Commitments issued under the Existing Credit Agreement, termination of
            the
            credit facilities established under the Existing Credit
            Agreement.

        

         

        (viii) Such
          other documents, certificates, instruments and information as any Lender
          or its
          counsel may have reasonably requested and satisfactory review by the Lenders
          of
          all environmental, litigation, insurance and other matters deemed appropriate
          by
          the Administrative Agent, including without limitation, data sufficient
          for
          analysis and projection of the Superior Cash Flow and/or the Oil and Gas
          Properties portion of the Borrowing Base Property (division orders, production
          payment checks or other evidence of payment by the purchaser of production)
          as
          reasonably deemed necessary by the Administrative Agent or the Required
          Lenders.

         

        (ix) All
          facility fees owed to the Lenders and all fees and expenses owing by Borrowers
          to Administrative Agent will have been paid, including the reasonable attorneys
          fees and expenses of legal counsel for the Administrative Agent that have
          been
          billed and submitted to the Agent as of the Closing Date (such amount payable
          by
          Borrowers being subject to the term sheet). 

         

        4.1.2 The
          Administrative Agent shall obtain the surrender to the Agent of all notes
          held
          by the lender parties to the Existing Credit Agreement by virtue of the
          refinancing by the Lenders in accordance with Schedule 2.

         

        4.2  Each
          Credit Extension.
          The
          Lenders will not be required to make any Credit Extension unless on the
          applicable Credit Extension Date:

         

        (i)
           There
          will exist no Default and the representations and warranties contained
          in
          Article V are then true and correct in all material respects as of such
          Credit
          Extension Date except to the extent a representation or warranty is stated
          to
          relate solely to an earlier date, in which case such representation or
          warranty
          will have been true and correct on and as of such earlier date.

         

        (ii) All
          legal
          matters incident to the making of such Credit Extension will be satisfactory
          to
          the Administrative Agent.

         

        (iii) No
          Material Adverse Effect will have occurred to, and no event or circumstance
          will
          have occurred that could reasonably be expected to cause a Material Adverse
          Effect to, Unit's consolidated financial condition or to the Credit Parties'
          businesses since the date of the financial statements most recently delivered
          pursuant to Sections 6.1 (i) and (ii) hereof.

         

        (iv) The
          making of such Loan or the issuance of such Letter of Credit will not be
          prohibited by any Law and will not subject any Lender or any LC Issuer
          to any
          penalty or other adverse condition under any Law.

         

        
          
            36

          

          
            
            

            
            

          

          
            
            

          

        

        (v) Each
          Borrower and Subsidiary Guarantor will be solvent.

         

        (vi) Administrative
          Agent will have received all documents and instruments which Administrative
          Agent has then reasonably requested, in addition to those described in
          Section
          4.1, as to (i) the accuracy and validity of or compliance with all
          representations, warranties, and covenants made by any Borrower or Subsidiary
          Guarantor in this Agreement in all material respects and the other Loan
          Documents, and (ii) the satisfaction of all conditions contained in this
          Agreement. 

         

        Each
          Borrowing Notice or request for issuance of a LC will constitute a
          representation and warranty by the Borrowers that the conditions contained
          in
          Section 4.2 have been satisfied.

         

        ARTICLE
          V

        REPRESENTATIONS
          AND WARRANTIES

         

        The
          Borrowers represent and warrant to the Lenders that:

         

        5.1  Existence
          and Good Standing.
          Each
          Credit Party is a corporation or limited liability company, duly and properly
          incorporated or organized, as the case may be, validly existing and (to
          the
          extent such concept applies to such entity) in good standing under the
          laws of
          its jurisdiction of incorporation or organization and has all requisite
          authority to carry on its business in each jurisdiction as now
          conducted.

         

        5.2  Authorization
          and Validity.
          Each
          Credit Party has the power and authority and legal right to execute and
          deliver
          the Loan Documents to which it is a party and to perform its obligations
          thereunder. The execution and delivery by each Credit Party of the Loan
          Documents to which it is a party and the performance of its obligations
          thereunder have been duly authorized by proper corporate proceedings. The
          Loan
          Documents to which a Credit Party is a party constitute legal, valid and
          binding
          obligations of such Credit Party enforceable against such Credit Party
          in
          accordance with their terms, except as enforceability may be limited by
          bankruptcy, insolvency or similar laws affecting the enforcement of creditors'
          rights generally.

         

        5.3  No
          Conflict; Government Consent.
          Neither
          the execution and delivery by any of the Credit Parties of the Loan Documents
          to
          which it is a party, nor the consummation of the transactions contemplated
          by
          the Loan Documents, nor compliance with the provisions of the Loan Documents
          will violate in any material respect (i) any law, rule, regulation, order,
          writ,
          judgment, injunction, decree or award binding on the Credit Parties or
          (ii) any
          of the Credit Parties' articles or certificate of incorporation, partnership
          agreement, certificate of partnership, articles or certificate of organization,
          by-laws, or operating or other management agreement, as the case may be,
          or
          (iii) the provisions of any indenture, instrument or agreement to which
          any of
          the Credit Parties is a party or is subject, or by which it, or its Property,
          is
          bound, or conflict with or constitute a default, or result in, or require,
          the
          creation or imposition of any Lien in, of or on the Property of the Credit
          Parties pursuant to the terms of any such indenture, instrument or agreement.
          No
          order, consent, adjudication, approval, license, authorization, or validation
          of, or filing, recording or registration with, or exemption by, or other
          action
          in respect of any governmental or public body or authority, or any subdivision
          thereof, which has not been obtained by the Credit Parties, is required
          to be
          obtained by the Credit Parties in connection with 

         

        
          
            37

          

          
            
            

            
            

          

          
            
            
the
            execution and delivery of the Loan Documents to which they are parties,
            the
            borrowings under this Agreement, the payment and performance by the Borrowers
            of
            the Obligations or the legality, validity, binding effect or enforceability
            of
            any of the Loan Documents.

        

         

        5.4  Financial
          Statements.
          The
          audited annual and unaudited quarterly, consolidated financial statements
          of
          Unit and its consolidated Subsidiaries previously delivered to the Lenders
          were
          prepared in accordance with GAAP (except that the unaudited interim financial
          statements were subject to normal and recurring year-end adjustments) in
          effect
          on the date such statements were prepared and fairly present the consolidated
          financial condition and operations of the Credit Parties at such date and
          the
          consolidated results of their operations for the period then ended.

         

        5.5  Material
          Adverse Effect.
          Since
          March 31, 2007, there has been no change in the business, Property, prospects,
          condition (financial or otherwise) or results of operations of the Credit
          Parties which could reasonably be expected to have a Material Adverse Effect.
          There is no fact known to the Borrowers which has a Material Adverse Effect
          or
          in the future is reasonably likely to have (so far as the Credit Parties
          can now
          foresee) a Material Adverse Effect and which has not been set forth in
          this
          Agreement or the other documents, certificates and statements furnished
          to the
          Administrative Agent by or on behalf of the Credit Parties prior to, or
          on, the
          Closing Date in connection with the transactions contemplated by this
          Agreement.

         

        5.6  Taxes.
          The
          Credit Parties have filed all United States federal tax returns and all
          other
          material tax returns which are required to be filed and have paid all taxes
          due
          pursuant to said returns or pursuant to any assessment received by the
          Credit
          Parties or any of their Subsidiaries, except such taxes, if any, that are
          being
          contested in good faith and as to which adequate reserves have been provided
          in
          accordance with GAAP and which no Lien has been filed or perfected. No
          tax liens
          have been filed and no claims are being asserted with respect to any such
          taxes.
          The charges, accruals and reserves on the books of the Credit Parties and their
          Subsidiaries in respect of any taxes or other governmental charges are
          adequate.

         

        5.7  Litigation
          and Contingent Obligations.
          There
          is no litigation, arbitration, governmental investigation, proceeding or
          inquiry
          pending or, to the knowledge of any of their officers, threatened against
          or
          affecting the Credit Parties which could reasonably be expected to have
          a
          Material Adverse Effect or which seeks to prevent, enjoin or delay the
          making of
          any Credit Extensions. Other than any liability incident to any litigation,
          arbitration or proceeding which could not reasonably be expected to have
          a
          Material Adverse Effect, the Credit Parties have no material Contingent
          Obligations not provided for or disclosed in the financial statements referred
          to in Section 5.4 except as set forth on Schedule 7 of this
          Agreement.

         

        5.8  Subsidiaries.
          The
          Disclosure Schedule contains an accurate list of all Subsidiaries of Unit
          as of
          the date of this Agreement, setting forth their respective jurisdictions
          of
          organization and the percentage of their respective capital stock or other
          ownership interests owned by the Unit or the other Credit Parties. All
          of the
          issued and outstanding shares of capital stock or other ownership interests
          of
          the Subsidiaries have been (to the extent such concepts are relevant with
          respect to such ownership interests) duly authorized and issued and are
          fully
          paid and non-assessable.

         

        
          
            38

          

          
            
            

            
            

          

          
            
            

          

        

        5.9  ERISA.
          Neither
          the Credit Parties nor any other member of the Controlled Group has incurred,
          or
          is reasonably expected to incur, any withdrawal liability to Multiemployer
          Plans. Each Plan complies in all material respects with all applicable
          requirements of law and regulations, no Reportable Event has occurred with
          respect to any Plan, neither the Credit Parties nor any other member of
          the
          Controlled Group has withdrawn from any Plan or initiated steps to do so,
          and no
          steps have been taken to reorganize or terminate any Plan except as disclosed
          in
          the Disclosure Schedule.

         

        5.10  Accuracy
          of Information.
          No
          information, exhibit or report furnished by the Credit Parties to the
          Administrative Agent or to any Lender in connection with the negotiation
          of, or
          compliance with, the Loan Documents contained any material misstatement
          of fact
          or omitted to state a material fact or any fact necessary to make the statements
          contained therein not misleading.

         

        5.11  Margin
          Stock.
          No part
          of the Loan proceeds of any Advances hereunder will be used to purchase
          or carry
          any margin stock or to extend credit to others for the purpose of purchasing
          or
          carrying any margin stock.
          If
          requested by the Administrative Agent or the Required Lenders, the Borrowers
          will, and will cause the other Credit Parties to, furnish to the Administrative
          Agent a statement in conformity with the requirements of Federal Reserve
          Form
          U-1, referred to in Regulation U, to the foregoing effect. No indebtedness
          being
          reduced or retired out of the proceeds of the Advances was or will be incurred
          for the purpose of purchasing or carrying any margin stock within the meaning
          of
          Regulation U or any "margin security" within the meaning of Regulation
          T.
          "Margin Stock" within the meaning of Regulation U does not constitute more
          than
          25% of the value of the consolidated assets of Unit and its
          Subsidiaries.

         

        5.12  Material
          Agreements.
          Unit
          has no actual knowledge of (i) any material agreement or material instrument
          to
          which any Borrower is a party or (ii) any charter or other corporate
          restriction, either of which (i) or (ii), under current conditions and
          circumstances known to Unit, constitutes or is reasonably expected to have
          a
          Material Adverse Effect. None of the Credit Parties is in default in the
          performance, observance or fulfillment of any of the obligations, covenants
          or
          conditions contained in (i) any agreement to which it is a party, which
          default
          could reasonably be expected to have a Material Adverse Effect or (ii)
          any
          agreement or instrument evidencing or governing Indebtedness, which default
          could reasonably be expected to have a Material Adverse Effect.

         

        5.13  Compliance
          With Laws.
          The
          Credit Parties have complied with all applicable statutes, rules, regulations,
          orders and restrictions of any domestic or foreign government or any
          instrumentality or agency thereof having jurisdiction over the conduct
          of their
          respective businesses or the ownership of their respective Property except
          for
          any failure to comply with any of the foregoing which could not reasonably
          be
          expected to have a Material Adverse Effect.

         

        5.14  Ownership
          of Properties.
          Unit
          and each of its Subsidiaries has marketable title to all of the properties
          and
          assets reflected as owned in the consolidated financial statements of Unit,
          in
          each case free and clear of all Liens other than Permitted Encumbrances
          (including those created under the Loan Documents described and defined
          in the
          Existing Credit Agreement) and such as do not materially and adversely
          affect
          the value of the property and do not materially interfere with the use
          made or
          proposed to be made of such property by Unit or its Subsidiaries, which
          such
          total Liens do not exceed $1,000,000 in the aggregate. The real property,
          improvements, equipment and personal property held under lease by Unit
          or any
          Subsidiary of Unit are held under valid enforceable leases, with such


         

        
          
            39

          

          
            
            

            
            

          

          
            
            
exceptions
            as are not material and do not materially interfere with the use made
            or
            proposed to be made of such real property, improvements, equipment or
            personal
            property by Unit or any Subsidiary of Unit. Each of Credit Parties possesses
            all
            licenses, permits, franchises, patents, copyrights, trademarks and trade
            names,
            and other intellectual property (or otherwise possesses the right to
            use such
            intellectual property without violation of the rights of any other Person)
            which
            are necessary to carry out its business as presently conducted and as
            proposed
            to be conducted hereafter. 

        

         

        5.15  Plan
          Assets; Prohibited Transactions.
          Neither
          the execution of this Agreement nor the making of Loans hereunder gives
          rise to
          a prohibited transaction within the meaning of Section 406 of ERISA or
          Section
          4975 of the Code. Since the effective date of Title IV of ERISA, no Reportable
          Event has occurred with respect to any Plan. The Credit Parties have fulfilled
          all their obligations under the funding standards of ERISA and the Code
          and are
          in compliance in all material respects with the applicable ERISA and Code
          provisions with respect to each Plan. Since the effective date of Title
          IV of
          ERISA there have not been any nor are there now existing any events or
          conditions that would permit any Plan to be terminated under circumstances
          which
          would cause the lien provided under Section 4068 of ERISA to attach to
          the
          assets of the Credit Parties or any of the Subsidiary Guarantors. No Borrower
          has (i) sought any waiver of the minimum funding standard under Section
          412 of
          the Code, (ii) failed to make any contribution or payment to any Plan,
          or made
          any amendment to any Plan, which has resulted or could result in the imposition
          of a Lien or the posting of a bond or other security under ERISA or the
          Code, or
          (iii) incurred any liability under Title IV of ERISA.

         

        5.16  Environmental
          Matters.
          Except
          as set forth on Schedule 4:

         

        (a)  To
          the
          best of the Borrowers' knowledge and belief, the Properties owned, leased
          or
          operated by the Credit Parties do not contain, and have not previously
          contained, any materials of environmental concern in amounts or concentrations
          which (i) constitute or constituted a violation of, or (ii) could give
          rise to
          liability under, any Environmental Law except in either case insofar as
          such
          violation or liability, or any aggregation thereof, is not reasonably likely
          to
          result in a Material Adverse Effect.

         

        (b)  To
          the
          best of the Borrowers' knowledge and belief, the Properties and all operations
          at the Properties are in compliance in all material respects, and have,
          for the
          lesser of the last five years or for the duration of their ownership, lease,
          or
          operation by the Credit Parties, been in compliance in all material respects
          with all applicable Environmental Laws, and there is no contamination at,
          under
          or about the Properties or violation of any Environmental Law with respect
          to
          the Properties or the business operated by the Credit Parties or any of
          their
          Subsidiaries (collectively, the "Business") which could interfere with
          the
          continued operation of the Properties or impair the fair saleable value
          thereof.

         

        (c)  None
          of
          the Credit Parties has received any notice of violation, alleged violation,
          non-compliance, liability or potential liability regarding environmental
          matters
          or 

         

        
          
            40

          

          
            
            

            
            

          

          
            
            
compliance
            with Environmental Laws with regard to any of the Properties or the Business,
            nor do any of the Borrowers have knowledge or reason to believe that
            any such
            notice will be received or is being threatened except insofar as such
            notice or
            threatened notice, or any aggregation thereof, does not involve a matter
            or
            matters that is or are reasonably likely to result in a Material Adverse
            Effect.

        

         

        (d)  To
          the
          best of the Borrowers' knowledge and belief, materials of environmental
          concern
          have not been transported or disposed of from the Properties in violation
          of, or
          in a manner or to a location which could give rise to liability under,
          any
          Environmental Law, nor have any materials of environmental concern been
          generated, treated, stored or disposed of at, on or under any of the Properties
          in violation of, or in a manner that could give rise to liability under,
          any
          applicable Environmental Law except insofar as any such violation or liability
          referred to in this paragraph, or any aggregation thereof, is not reasonably
          likely to result in a Material Adverse Effect.

         

        (e)  No
          judicial proceeding or governmental or administrative action is pending
          or, to
          the knowledge of the Borrowers, threatened, under any Environmental Law
          to which
          the Credit Parties thereof are or will be named as a party with respect
          to the
          Properties or the Business, nor are there any consent decrees or other
          decrees,
          consent orders, administrative orders or other orders, or other administrative
          or judicial requirements outstanding under any Environmental Law with respect
          to
          the Properties or the Business except insofar as such proceeding, action,
          decree, order or other requirement, or any aggregation thereof, is not
          reasonably likely to result in a Material Adverse Effect.

         

        (f)  There
          has
          been no release or threat of release of materials of environmental concern
          at or
          from the Properties, or arising from or related to the operations of the
          Borrower in connection with the Properties or otherwise in connection with
          the
          Business, in violation of or in amounts or in a manner that could give
          rise to
          liability under Environmental Laws except insofar as any such violation
          or
          liability referred to in this paragraph, or any aggregation thereof, is
          not
          reasonably likely to result in a Material Adverse Effect.

         

        5.17  Names
          and Places of Business.
          No
          Borrower has, during the preceding five years, had, been known by, or used
          any
          other trade or fictitious name. The chief executive office and principal
          place
          of business of each Credit Party are located at the address of the Credit
          Parties prescribed in Section 15.1. 

         

        5.18  Possession
          of Franchises, Licenses.
          The
          Credit Parties have in their possession, or have timely applied for, all
          franchises, certificates, licenses, permits and other authorizations from
          governmental political subdivisions or regulatory authorities, free from
          burdensome restrictions, that are necessary in any material respect for
          the
          ownership, maintenance and operation of their properties and assets, and
          none of
          the Credit Parties is in violation of any thereof in any material
          respect.

         

        
          
            41

          

          
            
            

            
            

          

          
            
            

          

        

        5.19  Rate
          Management Transactions.
          As of
          the Closing Date, Schedule 5 sets forth a true and complete list of all
          Rate
          Management Transactions (including commodity price swap agreements, forward
          agreements or contracts of sale which provide for prepayment for deferred
          shipment or delivery of oil, gas or other commodities) of the Credit Parties,
          listing the counterparties thereto.

         

        5.20  Insurance.
          The
          insurance certificate provided pursuant to Section 4.1(viii) will contain
          an
          accurate and complete description of all material policies of fire, liability,
          workmen's compensation and other forms of insurance owned or held by the
          Credit
          Parties. All such policies are in full force and effect, all premiums with
          respect thereto covering all periods up to and including the date of the
          closing
          have been paid, and no notice of cancellation or termination has been received
          with respect to any such policy. Such policies are sufficient for compliance
          with all requirements of law and of all agreements to which any Credit
          Party is
          a party; are valid, outstanding and enforceable policies; provide adequate
          insurance coverage in at least such amounts and against at least such risks
          (but
          including in any event public liability) as are usually insured against
          in the
          same general area by companies engaged in the same or a similar business
          for the
          assets and operations of the Credit Parties will remain in full force and
          effect
          through the respective dates set forth in such insurance certificate without
          the
          payment of additional premiums; and will not in any way be affected by,
          or
          terminate or lapse by reason of, the transactions contemplated by this
          Agreement. None of the Credit Parties have been refused any insurance with
          respect to its assets or operations, nor has its coverage been limited
          below
          usual and customary policy limits, by an insurance carrier to which it
          has
          applied for any such insurance or with which it has carried insurance during
          the
          last three years.

         

        5.21  No
          Default.
          No
          Credit Party is in default nor has any event or circumstance occurred which,
          but
          for the expiration of any applicable grace period or the giving of notice,
          or
          both, would constitute a default under any Material Indebtedness Agreement
          or
          instrument to which such Credit Party is a party or by which such Credit
          Party
          is bound which could have a Material Adverse Effect. No Default hereunder
          has
          occurred and is continuing.

         

        ARTICLE
          VI

        AFFIRMATIVE
          COVENANTS

         

        During
          the term of this Agreement, unless the Required Lenders will otherwise
          consent
          in writing:

         

        6.1  Reports.
          Unit
          will maintain and furnish to the Lenders:

         

        (i)
           Within
          80
          days after the close of each of its fiscal years, the financial statements
          of
          Unit and its Subsidiaries, together with an unqualified audit report certified
          by Unit's independent certified public accountants, prepared in accordance
          with
          GAAP on a consolidated basis, including a balance sheet as of the end of
          such
          period and statements of operations, stockholders equity and cash flows
          for such
          period.

         

        (ii) Within
          45
          days after the close of the first three quarterly periods of each of its
          fiscal
          years, consolidated unaudited balance sheets as at the close of each such
          period
          and statements of 

         

        
          
            42

          

          
            
            

            
            

          

          
            
            
operations,
            stockholders equity and cash flows for the period from the beginning
            of such
            fiscal year to the end of such quarter, all certified by its chief financial
            officer.

        

         

        (iii)
           Together
          with the financial statements required under Sections 6.1(i) and (ii),
          copies of
          all certifications made by officers of Unit to the SEC in connection with
          such
          financial statements and a compliance certificate in substantially the
          form of
          Exhibit B signed by Unit's chief financial officer showing the calculations
          necessary to determine compliance with this Agreement and stating that
          no
          Default exists, or if any Default exists, stating the nature and status
          of such
          Default.

         

        (iv)
           As
          soon
          as practicable and in any event within 10 days after the Credit Parties
          know
          that any Reportable Event has occurred with respect to any Plan, a statement,
          signed by the chief financial officer of Unit, describing said Reportable
          Event
          and the action which the Credit Parties propose to take regarding the Reportable
          Event.

         

        (v)
           As
          soon
          as practicable and in any event within 10 days after receipt by the Credit
          Parties, a copy of (a) any notice or claim to the effect that the Credit
          Parties
          is or may be liable to any Person as a result of the release by the Credit
          Parties, or any other Person of any toxic or hazardous waste or substance
          into
          the environment, and (b) any notice alleging any violation of any federal,
          state
          or local environmental, health or safety law or regulation by the Credit
          Parties, which, in either case, could reasonably be expected to have a
          Material
          Adverse Effect.

         

        (vi)
           Promptly
          on the furnishing to the stockholders of the Unit, copies of all financial
          statements, reports and proxy statements so furnished.

         

        (vii)
           By
          March
          1 of each year (commencing as of March 1, 2008), an Engineering Report
          prepared
          as of the prior December 31, by petroleum engineers who are employees of
          Credit
          Parties and audited by Ryder Scott Company, or such other firm of independent
          petroleum engineers chosen by Unit and acceptable to the Administrative
          Agent,
          concerning all Oil and Gas Properties and interests owned by any Credit
          Parties
          and their Subsidiaries which are located in or offshore of the United States
          and
          which have attributable to them proved oil or gas reserves. This reserve
          audit
          described above will encompass a review of the reserves associated with
          Oil and
          Gas Properties comprising at least 80% of the value stated in the report.
          The
          Engineering Report will be satisfactory to Administrative Agent, will contain
          sufficient information to enable Credit Parties to meet the reporting
          requirements concerning oil and gas reserves contained in Regulations S-K
          and
          S-X promulgated by the SEC, will take into account any "over/under produced"
          status under gas balancing arrangements, and will contain information and
          analysis comparable in scope to that contained in the Initial Engineering
          Report. 

         

        
          
            43

          

          
            
            

            
            

          

          
            
            

          

        

        (viii)
           By
          September 1 of each year (commencing as of September 1, 2007), and promptly
          following notice of a Special Redetermination under Section 2.6.4, an
          Engineering Report prepared as of the preceding June 30 (or the last day
          of the
          prior calendar month in the case of an additional redetermination) by petroleum
          engineers who are employees of Borrowers, together with an accompanying
          report
          on property sales, property purchases and changes in categories, both in
          the
          same form and scope as the reports in (x) above.

         

        (ix)
           By
          March
          1 and September 1 of each year, beginning September 1, 2007, a report describing
          the gross volume of production and sales attributable to production during
          the
          prior six-month period from the properties described in the Engineering
          Report
          in Section 6.1(vii) or Section 6.1(viii) and describing the related severance
          taxes, other taxes, and leasehold operating expenses attributable thereto
          and
          incurred during such month. By each March 1 and September 1 of each year,
          beginning September 1, 2007, the following internally prepared and generated
          information and data concerning Superior and the Superior Cash Flow: (i)
          most
          recent three (3) year historical volumes and cash flows, (ii) summary of
          material contracts, and (iii) budget for the then current fiscal year,
          each in
          form, scope and substance reasonably acceptable to the Agent.

         

        (x)
           Such
          other information (including non- financial information) as the Administrative
          Agent or any Lender may from time to time reasonably request.

         

        6.2  Use
          of
          Proceeds.
          The
          Borrowers will use such proceeds of the Credit Extensions as necessary
          to (i)
          refinance any Existing Indebtedness and the commitments issued in the Existing
          Credit Agreement, and provide financing for general working capital requirements
          for (a) exploration, development, production and acquisition of Oil and
          Gas
          Properties and other mineral interests, contract drilling services, gas
          gathering, gas processing and other midstream assets, (b) the issuance
          of
          standby LCs and (c) for general corporate purposes of the Borrowers. The
          Borrowers will not, nor will they permit any Subsidiary to, use any of
          the
          proceeds of the Advances to purchase or carry any "margin stock" (as defined
          in
          Regulations T and U).

         

        6.3  Notice
          of Default.
          Unit
          will give prompt notice in writing to the Lenders of the occurrence of
          any
          Default and of any other development, financial or otherwise, which could
          reasonably be expected to have a Material Adverse Effect.

         

        6.4  Conduct
          of Business.
          The
          Borrowers will, and will cause the other Credit Parties to, carry on and
          conduct
          their respective business in substantially the same manner and in substantially
          the same fields of enterprise as it is presently conducted and do all things
          necessary to remain duly incorporated or organized, validly existing and
          (to the
          extent such concept applies to such entity) in good standing as a domestic
          corporation, partnership or limited liability company in its jurisdiction
          of
          incorporation or organization, as the case may be, and maintain all requisite
          authority to conduct its business in each jurisdiction in which its business
          is
          conducted.

         

        6.5  Taxes.
          The
          Borrowers will, and will cause the other Credit Parties to, timely file
          complete
          and correct United States federal and applicable foreign, state and local
          tax
          returns required by law and pay when due all taxes, 

         

        
          
            44

          

          
            
            

            
            

          

          
            
            
assessments
            and governmental charges and levies upon it or its income, profits or
            Property,
            except those which are being contested in good faith by appropriate proceedings
            and with respect to which adequate reserves have been provided in accordance
            with GAAP.

        

         

        6.6  Insurance.
          The
          Borrowers will, and will cause the other Credit Parties to, maintain with,
          to
          the best of Unit's knowledge and belief, financially sound and reputable
          insurance companies insurance on all their Property in such amounts and
          covering
          such risks as is consistent with their prior business practice and deemed
          prudent by industry standards, and the Borrowers will furnish to any Lender
          upon
          request full information as to the insurance carried.

         

        6.7  Compliance
          With Laws.
          The
          Borrowers will, and will cause the other Credit Parties to, comply, in
          all
          material respects, with all laws, rules, regulations, orders, writs, judgments,
          injunctions, decrees or awards to which it may be subject including, without
          limitation, all Environmental Laws.

         

        6.8  Maintenance
          of Properties.
          The
          Borrowers will, and will cause the other Credit Parties to, do all things
          reasonably necessary to maintain, preserve, protect and keep their respective
          Property in good repair, working order and condition, and make all necessary
          and
          proper repairs, renewals and replacements so that its business carried
          on in
          connection therewith may be conducted at all times consistent with such
          Borrower's prior business practices.

         

        6.9  Inspection.
          The
          Borrowers will, and will cause the other Credit Parties to, permit the
          Administrative Agent and the Lenders, by their respective representatives
          and
          Administrative Agents, to inspect any of the Property, books and financial
          records of the Borrowers and each Subsidiary of any thereof, exclusive
          of
          records subject in good faith to attorney work product or privileged
          communications rules and standards, to examine and make copies of the books
          of
          accounts and other financial records of the Borrowers and each Subsidiary
          of any
          thereof, and to discuss the affairs, finances and accounts of the Borrowers
          and
          each Subsidiary with, and to be advised as to the same by, their respective
          officers at such reasonable times and intervals as the Administrative Agent
          or
          any Lender may designate.

         

        6.10  Deposit
          Accounts/Setoff.
          To
          secure the repayment of the Obligations, including Rate Management Obligations,
          each Borrower grants, and will cause the other Credit Parties to grant,
          to the
          Administrative Agent and each Lender and any applicable Affiliate of such
          Lenders (each a "Lender Affiliate"), a security interest, a lien, and a
          right of
          setoff and offset, each of which will be in addition to all other interests,
          liens, and rights of any Lender or Lender Affiliate at common Law, under
          the
          Loan Documents, or otherwise, and each of which will be upon and against
          (a) any
          and all moneys, securities and other property (and the proceeds therefrom)
          of
          such Credit Party now or hereafter held or received by or in transit to
          any
          Lender or Lender Affiliate from or for the account of such Credit Party,
          whether
          for safekeeping, custody, pledge, transmission, collection or otherwise,
          (b) any
          and all deposits and deposit accounts (general or special, time or demand,
          provisional or final) of such Credit Party with any Lender or Lender Affiliate,
          and (c) any other credits and claims of such Credit Party at any time existing
          against any Lender or Lender Affiliate, including claims under certificates
          of
          deposit (excluding from the foregoing security interest grant and right
          of set
          off and offset the accounts of the accounts at BOK as specified on Schedule
          6
          hereto (collectively, the "Excluded Accounts"). At any 

         

        
          
            45

          

          
            
            

            
            

          

          
            
            
time
            and
            from time to time during the continuance of any Event of Default, each
            Lender or
            Lender Affiliate is hereby authorized to foreclose upon, or to offset
            against
            the Obligations then due and payable (in either case without notice to
            any
            Credit Party), any and all items hereinabove referred to. The remedies
            of
            foreclosure and offset are separate and cumulative, and either may be
            exercised
            independently of the other without regard to procedures or restrictions
            applicable to the other.  

        

         

        6.11  Ratable
          Payments.
          If any
          Lender, whether by setoff or otherwise, has payment made to it upon its
          Outstanding Credit Exposure (other than payments received pursuant to Article
          III) in a greater proportion than that received by any other Lender, such
          Lender
          agrees, promptly upon demand, to purchase a portion of the Aggregate Outstanding
          Credit Exposure held by the other Lenders so that after such purchase each
          Lender will hold its Pro Rata Share of the Aggregate Outstanding Credit
          Exposure. If any Lender, whether in connection with setoff or amounts which
          might be subject to setoff or otherwise, receives collateral or other protection
          for its Obligations or such amounts which may be subject to setoff, such
          Lender
          agrees, promptly upon demand, to take such action necessary such that all
          Lenders share in the benefits of such collateral ratably in proportion
          to their
          respective Pro Rata Shares of the Aggregate Outstanding Credit Exposure.
          In case
          any such payment is disturbed by legal process, or otherwise, appropriate
          further adjustments will be made.

         

        6.12  Environmental
          Indemnities.
          Each of
          the Borrowers hereby agrees to indemnify, defend and hold harmless the
          Lenders
          and their respective officers, directors, employees, agents, consultants,
          attorneys, contractors and their respective affiliates, successors or assigns,
          or transferees from and against, and reimburse said Persons in full with
          respect
          to, any and all loss, liability, damage, fines, penalties, costs and expenses,
          of every kind and character, including reasonable attorneys' fees and court
          costs, known or unknown, fixed or contingent, occasioned by or associated
          with
          any claims, demands, causes of action, suits and/or enforcement actions,
          including any administrative or judicial proceedings, and any remedial,
          removal
          or response actions ever asserted, threatened, instituted or requested
          by any
          Persons, including any Tribunal, arising out of or related to: (a) the
          breach of
          any representation or warranty of the Borrowers contained in Section 5.16;
          (b)
          the failure of the Borrowers to perform any of their respective covenants
          contained in Section 6.7; (c) the ownership, construction, occupancy, operation,
          use of the Credit Parties' properties prior to the date on which the
          Indebtedness and obligations secured hereby have been paid and performed
          in
          full; provided, however, this indemnity shall not apply with respect to
          matters
          caused by or arising solely from the Agent's or the Lenders' activities
          during
          any period of time the Agent or the Lenders acquire ownership of the Credit
          Parties' properties.

         

        The
          indemnities contained in this Section 6.12 apply, without limitation, to
          any
          violation on or before the Release Date of any Environmental Laws and any
          liability or obligation relating to the environmental conditions on, under
          or
          about the Credit Parties' properties on or prior to the Release Date (including,
          without limitation: (a) the presence on, upon or in the Credit Parties'
          properties or release, discharge or threatened release on, upon or from
          the
          Credit Parties' properties of any polluting substances generated, used,
          stored,
          treated, disposed of or otherwise released prior to the Release Date, and
          (b)
          any and all damage to real or personal property or natural resources and/or
          harm
          or injury including wrongful death, to persons alleged to have resulted
          from
          such release of any polluting substances regardless of whether the act,
          omission, event or circumstances constituted a violation of any Environmental
          Law at the 

         

        
          
            46

          

          
            
            

            
            

          

          
            
            
time
            of
            its existence or occurrence). The term "release" shall have the meaning
            specified in applicable Environmental Laws and the terms "stored," "treated"
            and
            "disposed" shall have the meanings specified in applicable Environmental
            Laws;
            provided, however, any broader meanings of such terms provided by applicable
            laws of the State of Oklahoma shall apply.

        

         

        The
          provisions of this Section 6.12 shall be in addition to any other obligations
          and liabilities Credit Parties may have to the Agent or the Lenders at
          common
          law and shall survive the Release Date and shall continue thereafter in
          full
          force and effect.

         

        The
          Agent
          and the Lenders agree that in the event that such claim, suit or enforcement
          action is asserted or threatened in writing or instituted against them
          or any of
          their officers, employers, agents or contractors or any such remedial,
          removal
          or response action is requested of them or any of their officers, employees,
          agents or contractors for which the Agent or the Lenders may desire indemnity
          or
          defense hereunder, the Agent or the Lenders shall give prompt written
          notification thereof to Unit.

         

        Notwithstanding
          anything to the contrary stated herein, the indemnities created by this
          Section
          6.12 shall only apply to losses, liabilities, damages, fines, penalties,
          costs
          and expenses actually incurred by the Agent or the Lenders as a result
          of
          claims, demands, actions, suits or proceedings brought by Persons who are
          not
          the beneficiaries of any such indemnity. The Agent or the Lenders shall
          act as
          the exclusive agent for all indemnified Persons under this Section 6.12.
          With
          respect to any claims or demands made by such indemnified Persons, the
          Agent
          shall notify Unit within ten (10) days after the Agent's receipt of a writing
          advising the Agent of such claim or demand. Such notice shall identify
          (i) when
          such claim or demand was first made, (ii) the identity of the Person making
          it,
          (iii) the indemnified Person and (iv) the substance of such claim or demand.
          Failure by the Agent to so notify Unit within said ten (10) day period
          shall
          reduce the amount of the Credit Parties' obligations and liabilities under
          this
          Section 6.12 by an amount equal to any damages or losses suffered by the
          Credit
          Parties resulting from any prejudice caused the Credit Parties by such
          delay in
          notification from the Agent. Upon receipt of such notice, the Credit Parties
          shall have the exclusive right and obligation to contest, defend, negotiate
          or
          settle any such claim or demand through counsel of their own selection
          (but
          reasonably satisfactory to the Agent and the Lenders) and solely at Credit
          Parties' own cost, risk and expense; provided, that the Agent and the Lenders,
          at their own cost and expense, shall have the right to participate in any
          such
          contest, defense, negotiations or settlement. The settlement of any claim
          or
          demand hereunder by the Credit Parties, unless such settlement fully releases
          the Lenders from any and all liability thereon, may be made only upon the
          prior
          approval of the Lenders of the terms of the settlement, which approval
          shall not
          be unreasonably withheld.

         

        ARTICLE
          VII

        NEGATIVE
          COVENANTS

         

        7.1  Dividends.
          The
          Borrowers will not, nor will they permit any Subsidiary to, declare or
          pay any
          dividends or make any distributions on its capital stock (other than dividends
          payable in their own capital stock) or redeem, repurchase or otherwise
          acquire
          or retire any of its capital stock at any time outstanding; however, provided
          that no Default or Event of Default has occurred and remains outstanding
          and
          uncured, (i) any Subsidiary may declare and pay 

         

        
          
            47

          

          
            
            

            
            

          

          
            
            
dividends
            or make distributions to Unit or to a Wholly-Owned Subsidiary of Unit,
            (ii)
            during any fiscal year Unit may pay cash dividends in amounts not exceeding
            twenty-five percent (25%) of its Consolidated Net Income (after taxes)
            for the
            preceding fiscal year and (iii) any purchases by Unit of its outstanding
            common
            stock pursuant to a stock repurchase program approved by the Unit Board
            of
            Directors and conducted in compliance with the applicable rules and regulations
            of the SEC.

        

         

        7.2  Indebtedness.
          The
          Borrowers will not, nor will they permit any Subsidiary to, create, incur
          or
          suffer to exist any Indebtedness, except:

         

        (i)
           The
          Loans
          and the Reimbursement Obligations.

         

        (ii)
           Indebtedness
          (including Contingent Obligations) existing on the date hereof and described
          in
          the Disclosure Schedule.

         

        (iii) Indebtedness
          arising under Rate Management Agreements permitted by Section 7.10.

         

        (iv)
           Contingent
          Obligations permitted by Section 7.9.

         

        (v)
           Non-recourse
          Indebtedness in a restricted or special purpose Subsidiary (for which consent
          of
          the Required Lenders must be obtained) and as to which none of the Credit
          Parties (i) provides any guaranty or credit support of any kind (including
          any
          undertaking, guarantee, indemnity, agreement or instrument that would constitute
          Indebtedness) or (ii) is directly or indirectly liable (as a guarantor
          or
          otherwise); provided, that after giving effect to such Indebtedness outstanding
          from time to time, the Credit Parties are not in violation of any of the
          financial covenants of Article VIII.

         

        (vi) Normal
          and ordinary course trade debt and customary obligations relating to the
          operation of oil and gas producing properties, drilling rigs and gathering
          and
          processing systems and midstream asset operations.

         

        (vii) Unsecured
          senior indebtedness not in excess of $10,000,000 in the aggregate.

         

        (viii) Lease
          obligations (including building and office leases and leases for equipment)
          not
          in excess of $20,000,000 in the aggregate.

         

        (ix) Subordinated
          debt (including subordinated debt convertible to equity) in the aggregate
          maximum amount of $250,000,000 in form, scope and content reasonably acceptable
          to the Administrative Agent and the Required Lenders.

         

        (x) usual
          and
          customary insurance premium financed in the normal course of
          business.

         

        
          
            48

          

          
            
            

            
            

          

          
            
            

          

        

        (xi) indebtedness
          regarding self insured liabilities, including retentions under insurance
          policies.

         

        (xii) 
          miscellaneous items of Indebtedness not described in subsections (i) through
          (viii) above which do not in the aggregate (taking into account all such
          Indebtedness of the Credit Parties) exceed $10,000,000 at any one time
          outstanding.

         

        7.3  Limitation
          on Fundamental Changes.
          Borrowers will not enter into (nor permit any other Credit Party to enter
          into)
          any merger, consolidation or amalgamation, or liquidate, wind up or dissolve
          itself (or suffer any liquidation or dissolution), or convey, sell, lease,
          assign, transfer or otherwise dispose of, all or substantially all of its
          property, business or assets, or make any material change in its present
          method
          of conducting business, except:

         

        (a)  any
          Subsidiary of a Credit Party may be merged or consolidated with or into
          such
          Credit Party (provided that such Credit Party will be the continuing or
          surviving business entity or other entity) or with or into any one or more
          wholly owned Subsidiaries of the Credit Party that is a Borrower or Subsidiary
          Guarantor (provided that the wholly owned Borrower or Subsidiary Guarantor
          will
          be the continuing or surviving business entity or other entity);
          and

         

        (b)  any
          Wholly Owned Subsidiary may sell, lease, transfer or otherwise dispose
          of any or
          all of its assets (upon voluntary liquidation or otherwise) to such Borrower
          or
          any other Wholly Owned Subsidiary of such Borrower that is a Borrower or
          Subsidiary Guarantor.

         

        (c)  so
          long
          as no Default will exist or be caused as a result, a Person may be merged
          or
          consolidated with or into a Borrower so long as the Borrower is the continuing
          or surviving corporation.

         

        7.4  Sale
          of Assets.
          The
          Borrowers will not (nor will they permit any other Credit Party to) lease,
          sell
          or otherwise dispose of its Property to any other Person, except:

         

        (i)
           Sales
          of
          inventory in the ordinary course of business or the sale of assets not
          included
          in the Borrowing Base of not more than $125,000,000 in the aggregate; provided,
          however, in no event shall any drilling rigs of any of the Borrowers be
          sold or
          otherwise disposed of after the occurrence of a Default or an Event of
          Default
          that remains uncured without the prior written consent of the Required
          Lenders,
          and the net proceeds thereof shall be applied as a mandatory principal
          prepayment of the Obligations.

         

        (ii)
           Disposition
          of equipment and other personal property that is replaced by equivalent
          property
          or consumed in the normal operation of the Property of the respective
          Borrowers.

         

        (iii)
           Dispositions
          of a portion of its Property in connection with operating agreements, farmouts,
          farmins, joint exploration and development agreements and other agreements
          customary in the oil and gas industry that are entered into for the purposes
          of
          developing its Property and under 

         

        
          
            49

          

          
            
            

            
            

          

          
            
            
which
            it
            receives relatively equivalent consideration; provided, however, disposition
            of
            any Borrowing Base Properties under this clause (iii) shall be subject
            to the
            ten percent (10%) limitation of clause (iv) below to the extent the
            consideration received in exchange therefor results in a net Borrowing
            Base
            decrease of more than such 10%. 

        

         

        (iv)
           Leases,
          sales or other dispositions of its Property that, together with all other
          Property of the Credit Parties and their Subsidiaries previously leased,
          sold or
          disposed of (other than (i), (ii) and (iii) above) as permitted by this
          Section
          7.4 during the period since the most recent Determination Date, do not
          constitute more than ten percent (10%) of the Engineered Value of the Borrowing
          Base Properties as determined by Administrative Agent in its sole discretion;
          further provided, however, to the extent such aggregate consideration for
          all
          asset sales or other dispositions of Properties exceeds five percent (5%)
          of the
          Borrowing Base during any period between semi-annual Determination Dates,
          the
          Required Lenders will have the option to reduce the Borrowing Base by the
          amount
          of such proceeds and, further, provided, that any resulting Deficiency
          (as
          defined in Section 2.6.6) must be cured by the Credit Parties in compliance
          with
          Section 2.8(b).

         

        (v)
           Hydrocarbon
          Interests to which no proved reserves of Hydrocarbons are properly
          attributed.

         

        7.5  Investments
          and Acquisitions.
          The
          Borrowers will not (nor will they permit any other Credit Party to) make
          or
          suffer to exist any Investments (including without limitation, loans and
          advances to, and other Investments in, Subsidiaries), or commitments therefor,
          or to create any Subsidiary or to become or remain a partner in any partnership
          or joint venture, or to make any Acquisition of any Person, except:

         

        (i)
           Cash
          Equivalent Investments.

         

        (ii)
           Investments
          between Credit Parties or in any Credit Party's Subsidiaries which are
          Subsidiary Guarantors or Subsidiaries of any Credit Party with respect
          to which
          100% of its Equity has been pledged to Administrative Agent.

         

        (iii)
           Investments
          in existence on the date hereof and described on the Disclosure
          Schedule.

         

        (iv)
           Investments
          in associations, joint ventures, and other relationships (a) that are
          established pursuant to standard form operating agreements or similar agreements
          or which are partnerships for purposes of federal income taxation only,
          (b) that
          are not corporations or partnerships (or subject to the Uniform Partnership
          Act
          or other applicable state partnership act) under applicable state law,
          (d) which
          are limited partnerships formed for investment by employees and Directors
          of
          Unit and its Subsidiaries in the oil and gas exploration and development
          operations of 

         

        
          
            50

          

          
            
            

            
            

          

          
            
            
Unit
            and
            its Subsidiaries; or (d) whose businesses are limited to the exploration,
            development and operation of oil, gas or mineral properties and interests
            owned
            directly by the parties in such associations, joint ventures or relationships
            in
            which the ownership interest of any Credit Party or its Subsidiary is
            in direct
            proportion to the amount of such Investment.

        

         

        (v)
           Acquisitions
          by any of the Credit Parties or by any of the Material Subsidiaries or
          investments by any thereof in Subsidiaries of the Credit Parties that are
          not
          Material Subsidiaries that do not exceed $60,000,000 per such
          Acquisition.

         

        (vi)
           Miscellaneous
          items of Investments and Acquisitions not described in clauses (i) through
          (v)
          above which (taking into account all such miscellaneous Investments and
          Acquisitions of the Credit Parties and their Subsidiaries) do not exceed
          an
          aggregate amount of $60,000,000 during any fiscal year of Unit.

         

        7.6  Liens.
          The
          Borrowers will not (nor will they permit any other Credit Party to) create,
          incur, or suffer to exist any Lien in, of or on the Property of the Credit
          Parties or any of their Subsidiaries, except:

         

        (i)
           Liens
          for
          taxes, assessments or governmental charges or levies on its Property if
          the same
          will not at the time be delinquent or thereafter can be paid without penalty,
          or
          are being contested in good faith and by appropriate proceedings and for
          which
          adequate reserves in accordance with GAAP will have been set aside on its
          books.

         

        (ii)
           Liens
          imposed by law, such as carriers', warehousemen's and mechanics' liens
          and other
          similar liens arising in the ordinary course of business which secure payment
          of
          obligations not more than 90 days past due or which are being contested
          in good
          faith by appropriate proceedings and for which adequate reserves, in accordance
          with GAAP, will have been set aside on its books.

         

        (iii)
           Liens
          arising out of pledges or deposits under worker's compensation laws,
          unemployment insurance, old age pensions, or other social security or retirement
          benefits, or similar legislation.

         

        (iv)
           Utility
          easements, building restrictions and such other encumbrances or charges
          against
          real property as are of a nature generally existing with respect to properties
          of a similar character and which do not in any material way affect the
          marketability of the same or interfere with the use thereof in the business
          of
          the Credit Parties or their Subsidiaries.

         

        (v)
           Liens
          existing on the date hereof and described on the Disclosure
          Schedule.

         

        (vi)
           Liens
          in
          favor of the Administrative Agent, for the benefit of the Lenders,.

         

        
          
            51

          

          
            
            

            
            

          

          
            
            

          

        

        (vii)
           Liens
          on
          Property to secure not more than $5,000,000 in the aggregate of the Indebtedness
          permitted by Section 7.2(v).

         

        (viii)
           With
          respect to Property subject to any Loan Document, Liens burdening such
          Property
          that are expressly allowed by such Loan Document.

         

        (ix)
           Liens
          arising under operating agreements, unitization, pooling agreements and
          other
          agreements customary in the oil and gas industry securing amounts owed
          to
          operators and joint owners of Oil and Gas Properties that will not at the
          time
          be delinquent, or thereafter can be paid without penalty, or are being
          contested
          in good faith and by appropriate proceedings and for which adequate reserves
          in
          accordance with GAAP will have been set aside on its books.

         

        (x)
           Contracts,
          agreements, instruments, obligations, defects and irregularities affecting
          the
          Property that individually or in the aggregate are not such as to interfere
          materially with the use, operation or value of the Property.

         

        (xi) Any
          lien
          existing on any asset prior to its acquisition by a Borrower or one of
          its
          Subsidiaries and not created in contemplation of the acquisition.

         

        (xii) Any
          extension, renewal or replacement (or successive extensions, renewals or
          replacements), as a whole or in part, of any Liens referred to in (i) -
          (xi)
          above for amounts not exceeding the principal amount of the indebtedness
          secured
          by the Lien so extended, renewed or replaced.

         

        7.7  Affiliates.
          The
          Borrowers will not (nor will they permit any other Credit Party to) enter
          into
          any transaction (including, without limitation, the purchase or sale of
          any
          Property or service) with, or make any payment or transfer to, any Affiliate
          except in the ordinary course of business and pursuant to the reasonable
          requirements of the Credit Parties' or such Subsidiary's business and on
          fair
          and reasonable terms no less favorable to the Credit Parties or such Subsidiary
          than the Credit Parties or such Subsidiary would obtain in a comparable
          arms-length transaction.

         

        7.8  Sale
          and Leaseback Transactions and other Off-Balance Sheet
          Liabilities.
          The
          Borrowers will not (nor will they permit any other Credit Party to) enter
          into
          or suffer to exist any (i) Sale and Leaseback Transaction or (ii) any other
          transaction pursuant to which it incurs or has incurred Off-Balance Sheet
          Liabilities, except for Rate Management Obligations permitted to be incurred
          under the terms of Section 7.10.

         

        7.9  Contingent
          Obligations.
          The
          Borrowers will not (nor will they permit any other Credit Party to) make
          or
          suffer to exist any Contingent Obligation (including, without limitation,
          any
          Contingent Obligation with respect to the obligations of a Subsidiary),
          except
          (i) by endorsement of instruments for deposit or collection in the ordinary
          course of business, (ii) the Reimbursement Obligations, (iii) the Subsidiary
          Guaranty, (iv) excluding existing Contingent Obligations set forth on Schedule
          7
          and the Disclosure Schedule, other Contingent Obligations not to exceed
          an
          outstanding aggregate amount of $25,000,000 at any time, and (v) liabilities
          associated or accrued for abandonment and 

         

        
          
            52

          

          
            
            

            
            

          

          
            
            
plugging
            of Credit Parties' Oil and Gas Properties, and (vi) as general partner
            of the
            limited partnerships formed annually to allow employees and directors
            of Unit to
            participate in certain of its oil and gas exploration and production
            operations.

        

         

        7.10  Financial
          Contracts.
          None of
          the Credit Parties will be a party to or in any manner be liable on any
          Financial Contract except:

         

        (a)  contracts
          entered into with the purpose and effect of fixing prices on oil or gas
          expected
          to be produced by the Credit Parties and their Subsidiaries, provided that
          at
          all times: (i) no such contract fixes a price for a term of more than 48
          months;
          (ii) the aggregate monthly production covered by all such contracts for
          any
          single month does not in the aggregate exceed eighty percent (80%) of the
          aggregate Engineered Projected Production (as defined below) of the Credit
          Parties and their Subsidiaries anticipated to be sold in the ordinary course
          of
          their businesses for such month, (iii) no such contract requires the Credit
          Parties or any of their Subsidiaries to put up money, assets, letters of
          credit
          or other security against the event of its nonperformance prior to actual
          default by such Credit Parties or any of their Subsidiaries in performing
          their
          obligations thereunder (unless such counterparty is a Lender or any Lender
          Affiliate), and (iv) each such contract is with a counterparty or has a
          guarantor of the obligation of the counterparty who (unless such counterparty
          is
          a Lender or any Lender Affiliate) at the time the contract is made has
          long-term
          obligations rated BBB+ or Baal or better, respectively, by either Moody's
          or
          S&P. As used in this subsection, the term "Engineered Projected Production"
          means the Engineered Value of projected production of oil or gas (measured
          by
          volume unit or BTU equivalent, not sales price) for the term of the contracts
          or
          a particular month, as applicable, from properties and interests owned
          by the
          Credit Parties and their Subsidiaries that are located in or offshore of
          the
          United States and are proved developed producing (PDP) reserves (as determined
          by the Administrative Agent in its oil and gas lending criteria), as such
          production is projected in the most recent report delivered pursuant to
          Section
          6.1(vii) or (viii), after deducting projected production from any properties
          or
          interests sold or under contract for sale that had been included in such
          report
          and after adding projected production from any properties or interests
          that had
          not been reflected in such report but that are reflected in a separate
          or
          supplemental reports meeting the requirements of such Section 6.1(vii)
          or (viii)
          above and otherwise are satisfactory to Administrative Agent; 

         

        (b)  contracts
          entered into by Credit Parties or their Subsidiaries with the purpose and
          effect
          of fixing interest rates on a principal amount of indebtedness of such
          Credit
          Parties or their Subsidiaries that is accruing interest at a variable rate,
          provided that no such contract will be entered into by Credit Parties or
          any of
          their Subsidiaries for speculative purposes; and

         

        (c)  such
          contracts comply with the Rate Management Transactions’ criteria disclosed in
          writing to the Administrative Agent.

         

        
          
            53

          

          
            
            

            
            

          

          
            
            

          

        

        7.11  Letters
          of Credit.
          The
          Borrowers will not (nor will they permit any other Credit Party to) apply
          for or
          become liable upon or in respect of any Letter of Credit other than
          LCs.

         

        7.12  Prohibited
          Contracts.
          Except
          as expressly permitted in this Agreement or the other Loan Documents, none
          of
          Borrowers will (nor will they permit any other Credit Party to), directly
          or
          indirectly, enter into, create, or otherwise allow to exist any contract
          or
          other consensual restriction on the ability of any Subsidiary of a Borrower
          to:
          (a) pay dividends or make other distributions to other Credit Parties,
          (b) to
          redeem equity interests held in it by other Credit Parties, or (c) to repay
          loans and other indebtedness owing by it to other Credit Parties. 

         

        7.13  Negative
          Pledge.
          Except
          only for Liens permitted by applicable subsections of Section 7.6, none
          of the
          Borrowers will (nor will they permit any other Credit Party to) cause or
          permit
          the pledging, encumbrance, mortgaging, granting of a consensual security
          interest or any other type of pledge, charge or imposition of a Lien against
          any
          of the Credit Parties’ or any Subsidiaries' (i) oil and gas mining and mineral
          interests, rights and properties, proved, developed, producing or otherwise
          (whether now owned or hereafter created or acquired) constituting 100%
          of the
          Engineered Value thereto, to secure any Indebtedness (including Contingent
          Obligations), or (ii) midstream assets, without the prior written consent
          of the
          Administrative Agent and the Lenders. This covenant, to the fullest extent
          permitted by applicable law, will be deemed and construed as a "negative
          pledge"
          of all such assets referenced in clauses (i) and (ii) above in favor of
          the
          Administrative Agent for the benefit of the Lenders. 

         

        ARTICLE
          VIII

        FINANCIAL
          COVENANTS

         

        8.1  Current
          Ratio.
          Unit
          will not permit the ratio, determined as of the end of each of Unit's fiscal
          quarters, of (i) Unit's consolidated Current Assets (including the then
          Available Aggregate Commitment) to (ii) Unit's consolidated Current Liabilities
          (including the current portion of the Loans), to be less than 1.0 to
          1.0.

         

        8.2  Leverage
          Ratio.
          Unit
          will not permit the ratio, determined as of the end of each of Unit's fiscal
          quarters, of (i) Long Term Debt to (ii) Consolidated EBITDA for the then
          most-recently ended rolling four (4) fiscal quarters to be greater than
          3.50 to
          1.0.

         

        8.3  Minimum
          Consolidated Net Worth.
          Unit
          will not permit Unit's Consolidated Net Worth to be less than Nine Hundred
          Million Dollars ($900,000,000) as tested quarterly effective as of the
          close of
          each fiscal quarter of Unit and annually effective as of the close of each
          fiscal year end, based on the quarterly and annual financial statement
          reporting
          requirements of Section 6.1(i) and (ii), respectively.

         

        ARTICLE
          IX

        GUARANTEES

         

        9.1  Guarantees.
          Unit
          will cause each current Material Subsidiary and each future Material Subsidiary
          to guarantee the prompt payment and performance when due of the Obligations
          in
          accordance with the terms and provisions of the Subsidiary Guaranty. As
          soon as
          practicable and in any event within ten (10) days after any Person becomes
          a
          direct or indirect Material Subsidiary, Unit will provide the Administrative
          Agent written notice thereof and 

         

        
          
            54

          

          
            
            

            
            

          

          
            
            
will
            cause such Person to execute a Subsidiary Guaranty Joinder Agreement
            in
            substantially the same form as Schedule 1 to the Subsidiary Guaranty.
            Prior to
            any Investments being permitted to be made in any other Subsidiary of
            the Credit
            Parties in excess of the amount permitted by Section 7.5(v) such Subsidiary
            will
            also execute and deliver such a Subsidiary Guaranty to the Administrative
            Agent
            for the ratable benefit of each Lender, together with such other certificates
            or
            documents as Administrative Agent reasonably deems necessary or appropriate
            to
            confirm such Subsidiary Guaranty, including without limitation, closing
            opinions
            (supplementing the closing opinion required by Section 4.1.1(v) of this
            Agreement) as required by the Administrative Agent or the Required Lenders
            in
            connection with the Subsidiary Guaranty instruments executed from time
            to time
            by Material Subsidiaries under this Section 9.1.

        

         

        9.2  Negative
          Pledge/Production Proceeds.
          Notwithstanding that, by the terms hereof, the Borrowers are granting to
          Administrative Agent and Lenders a "negative pledge" of the Oil and Gas
          Properties now or hereafter owned or acquired and all of the "production
          proceeds" accruing to the property covered thereby and all gathering and
          processing and related midstream assets, including Borrowers' commercially
          reasonable and best efforts to so restrict other Credit Parties, so long
          as no
          Default has occurred Borrowers and their Subsidiaries may continue to receive
          from the purchasers of production all such production proceeds from the
          Oil and
          Gas Properties. Upon the occurrence of a Default, Administrative Agent
          and
          Lenders may obtain possession of all production proceeds then held by Borrowers
          and their Subsidiaries or to receive directly from the purchasers of production
          all production proceeds. 

         

        ARTICLE
          X

        EVENTS
          OF DEFAULTS

         

        The
          occurrence of any one or more of the following events will constitute an
          Event
          of Default:

         

        10.1  Any
          representation or warranty made or deemed made by or on behalf of any of
          the
          Credit Parties to the Lenders or the Administrative Agent under or in connection
          with this Agreement, any Credit Extension, or any certificate, report or
          information delivered in connection with this Agreement or any other Loan
          Document is materially false on the date as of which made.

         

        10.2  Nonpayment
          of principal of any Loan when due, nonpayment of any Reimbursement Obligation
          within one Business Day after the same becomes due, or nonpayment of interest
          upon any Loan or of any commitment fee, LC Fee or other obligations under
          any of
          the Loan Documents within ten (10) days after the same becomes due.

         

        10.3  The
          breach by the Borrowers of any of the terms or provisions of Section 2.21,
          Section 6.3, Article VII, Article VIII or Article IX of this Agreement
          and
          failure to cure within twenty (20) days following written notice from the
          Administrative Agent or any Lender to Unit.

         

        10.4  The
          breach by the Borrowers (other than a breach which constitutes a Default
          under
          another Section of this Article X) of any of the terms or provisions of
          this
          Agreement which is not remedied within thirty (30) days after written notice
          from the Administrative Agent or any Lender to Unit.

         

        
          
            55

          

          
            
            

            
            

          

          
            
            

          

        

        10.5  Failure
          of any Credit Party to pay when due any Material Indebtedness; or the default
          by
          any Credit Party in the performance (beyond the applicable grace period
          with
          respect thereto, if any) of any term, provision or condition contained
          in any
          Material Indebtedness Agreement, or any other event occurs or condition
          exists,
          the effect of which default, event or condition is to cause, or to permit
          the
          holder(s) of such Material Indebtedness or the lender(s) under any Material
          Indebtedness Agreement to cause, such Material Indebtedness to become due
          prior
          to its stated maturity or any commitment to lend under any Material Indebtedness
          Agreement to be terminated prior to its stated expiration date; or any
          Material
          Indebtedness of any Credit Party or any of their Subsidiaries will be declared
          to be due and payable or required to be prepaid or repurchased (other than
          by a
          regularly scheduled payment) prior to the stated maturity thereof; or the
          Credit
          Parties will not pay, or admit in writing its inability to pay, its debts
          generally as they become due.

         

        10.6  No
          Credit
          Party will (i) have an order for relief entered with respect to it under
          the
          Federal bankruptcy laws as now or hereafter in effect, (ii) make an assignment
          for the benefit of creditors, (iii) apply for, seek, consent to, or acquiesce
          in, the appointment of a receiver, custodian, trustee, examiner, liquidator
          or
          similar official for it or any substantial portion of its Property, (iv)
          institute any proceeding seeking an order for relief under the Federal
          bankruptcy laws as now or hereafter in effect or seeking to adjudicate
          it a
          bankrupt or insolvent, or seeking dissolution, winding up, liquidation,
          reorganization, arrangement, adjustment or composition of it or its debts
          under
          any law relating to bankruptcy, insolvency or reorganization or relief
          of
          debtors or fail to file an answer or other pleading denying the material
          allegations of any such proceeding filed against it, (v) take any corporate
          or
          partnership action to authorize or effect any of the foregoing actions
          set forth
          in this Section 10.6 or (vi) fail to contest in good faith any appointment
          or
          proceeding described in Section 10.7.

         

        10.7  Without
          the application, approval or consent of the Credit Parties, a receiver,
          trustee,
          examiner, liquidator or similar official will be appointed for any Credit
          Party
          or a proceeding described in Section 10.6(iv) will be instituted against
          any
          Credit Party and such appointment continues undischarged or such proceeding
          continues undismissed or unstayed for a period of 60 consecutive
          days. 

         

        10.8  Any
          court, government or governmental agency condemns, seizes or otherwise
          appropriates, or takes custody or control of, all or any portion of the
          Property
          of any Credit Party which, when taken together with all other Property
          of such
          Credit Party so condemned, seized, appropriated, or taken custody or control
          of,
          during the twelve-month period ending with the month in which any such
          action
          occurs, constitutes a Material Adverse Effect.

         

        10.9  Any
          of
          the Credit Parties fails within 30 days to pay, bond or otherwise discharge
          one
          or more (i) judgments or orders for the payment of money in excess of $1,000,000
          (or the equivalent thereof in currencies other than U.S. Dollars) in the
          aggregate, or (ii) non-monetary judgments or orders which, individually
          or in
          the aggregate, could reasonably be expected to have a Material Adverse
          Effect,
          which judgment(s), in any such case, is/are not stayed on appeal or otherwise
          being appropriately contested in good faith.

         

        10.10  The
          Unfunded Liabilities of all Single Employer Plans exceeds in the aggregate
          $500,000 or any material Reportable Event occurs in connection with any
          Plan.

         

        
          
            56

          

          
            
            

            
            

          

          
            
            

          

        

        10.11  Nonpayment
          by any Credit Party of any Rate Management Obligation when due or the breach
          by
          any Credit Party or any Subsidiary of any term, provision or condition
          contained
          in any Rate Management Transaction or any transaction of the type described
          in
          the definition of "Rate Management Transactions," whether or not any Lender
          or
          Affiliate of a Lender is a party thereto, after taking into account any
          applicable grace period, but only if such nonpayment or breach constitutes
          a
          Material Adverse Effect.

         

        10.12  Any
          Change in Control of any of the Credit Parties occurs.

         

        10.13  Any
          Credit Party (i) is the subject of any proceeding or investigation pertaining
          to
          the release by any Credit Party, any of their Material Subsidiaries or
          any other
          Person of any toxic or hazardous waste or substance into the environment,
          or
          (ii) violates any Environmental Law, which, in the case of an event described
          in
          clause (i) or clause (ii), could reasonably be expected to have a Material
          Adverse Effect.

         

        10.14  Any
          Subsidiary Guaranty fails to remain in full force or effect or any action
          is
          taken to discontinue or to assert the invalidity or unenforceability of
          any
          Subsidiary Guaranty, or any Subsidiary Guarantor fails to comply with any
          of the
          terms or provisions of any Subsidiary Guaranty to which it is a party,
          or any
          Subsidiary Guarantor denies that it has any further liability under any
          Subsidiary Guaranty to which it is a party, or will give notice to such
          effect.

         

        10.15  Any
          Credit Party fails to comply in any material respect with any of the terms
          or
          provisions of any Loan Document.

         

        10.16  The
          representations and warranties set forth in Section 5.15 ("Plan Assets;
          Prohibited Transactions") at any time are not true and correct in any material
          respect.

         

        ARTICLE
          XI

        ACCELERATION,
          WAIVERS, AMENDMENTS AND REMEDIES

         

        11.1  Acceleration.

         

        (i) If
          any
          Default described in Section 10.6 or 10.7 occurs with respect to the Credit
          Parties, the obligations of the Lenders to make Loans hereunder and the
          obligation and power of the LC Issuer to issue LCs will automatically terminate
          and the Obligations will immediately become due and payable without any
          election
          or action on the part of the Administrative Agent, the LC Issuer or any
          Lender
          and the Credit Parties will be and become thereby unconditionally obligated,
          without any further notice, act or demand, to pay to the Administrative
          Agent an
          amount in immediately available funds equal to the amount of LC Obligations
          in
          cash or cash equivalents satisfactory to the Administrative Agent. If any
          other
          Event of Default occurs and is continuing, the Required Lenders (or the
          Administrative Agent with the consent of the Required Lenders) may (a)
          terminate
          or suspend the obligations of the Lenders to make Loans hereunder and the
          obligation and power of the LC Issuer to issue LCs, or declare the Obligations
          to be due and payable, or both, in which event the Obligations will become
          immediately due and payable, without presentment, demand, protest or notice
          of
          any kind, all of which the Credit Parties hereby expressly waive, and (b)
          upon
          notice to the Credit Parties and in addition to the continuing right to
          demand
          payment of all amounts payable under this Agreement, make 

         

        
          
            57

          

          
            
            

            
            

          

          
            
            
demand
            on
            the Credit Parties to pay, and the Credit Parties will, forthwith upon
            such
            demand and without any further notice or act, immediately pay to the
            Administrative Agent the amount of such LC Obligations.

        

         

        (ii) The
          Administrative Agent may at any time or from time to time, after such funds
          are
          deposited with the Administrative Agent, apply such funds to the payment
          of the
          Obligations and any other amounts as may have become due and payable by
          the
          Credit Parties to the Lenders or the LC Issuer under the Loan
          Documents.

         

        11.2  Amendments.
          Subject
          to the provisions of this Section 11.2, the Required Lenders (or the
          Administrative Agent with the consent in writing of the Required Lenders)
          and
          the Credit Parties may enter into supplemental agreements for the purpose
          of
          adding or modifying any provisions to the Loan Documents to which they
          are
          parties or changing in any manner the rights of the Lenders or the Borrowers
          under this Agreement or waiving any Default or Event of Default under this
          Agreement; provided, however, that no such supplemental agreement will,
          without
          the consent of all of the Lenders:

         

        (i)
           Extend
          the final maturity of any Loan, or extend the expiration date of an LC
          to a date
          after the Facility Termination Date or postpone any regularly scheduled
          payment
          of principal of any Loan or forgive all or any portion of the principal
          amount
          thereof or any Reimbursement Obligation related thereto, or reduce the
          rate or
          extend the time of payment of interest or fees thereon or Reimbursement
          Obligations related thereto.

         

        (ii)
           Reduce
          the percentage specified in the definition of Required Lenders or eliminate
          or
          delete the Borrowing Base concept of Section 2.6 of this Agreement.

         

        (iii)
           Extend
          the Facility Termination Date, or reduce the amount or extend the payment
          date
          for, the mandatory principal payments required under Section 2.8(b), or
          increase
          the (a) Maximum Credit Amount, (b) Aggregate Commitment Amount above the
          Maximum
          Credit Amount, (c) Borrowing Base contrary to the last sentence of Section
          2.6.2(b), (d) amount of the Commitment of any Lender under this Agreement
          or (e)
          commitment to issue LCs.

         

        (iv) Amend
          this Section 11.2 or permit the Borrowers to assign their rights under
          this
          Agreement.

         

        (v) No
          amendment of any provision of this Agreement relating to the Administrative
          Agent will be effective without the written consent of the Administrative
          Agent,
          and no amendment of any provision relating to the LC Issuer will be effective
          without the written consent of the LC Issuer.

         

        11.3  Preservation
          of Rights.
          No
          delay or omission of the Lenders, the LC Issuer or the Administrative Agent
          to
          exercise any right under the Loan Documents will impair such right or be
          construed to be a waiver of any Default or Event of Default or an acquiescence
          in such Default or Event of Default, and the making of a Credit Extension
          notwithstanding the existence of a Default or Event of Default or the inability
          of the Credit Parties to satisfy the conditions precedent to such Credit
          Extension will not constitute any waiver or acquiescence. Any single or
          partial
          exercise of any such right will not preclude other or further exercise
          of such
          right or the exercise of any other right, and 

         

        
          
            58

          

          
            
            

            
            

          

          
            
            
no
            waiver, amendment or other variation of the terms, conditions or provisions
            of
            the Loan Documents whatsoever will be valid unless in writing signed
            by the
            Lenders required pursuant to Section 11.2, and then only to the extent
            specifically set forth in writing. All remedies contained in the Loan
            Documents
            or by law or equity afforded will be cumulative and will be available
            to the
            Administrative Agent, the LC Issuer and the Lenders until the Obligations
            have
            been paid in full.

        

         

        ARTICLE
          XII

        GENERAL
          PROVISIONS

         

        12.1  Survival
          of Agreements.
          All
          covenants, agreements, representations and warranties contained in this
          Agreement will survive the making of the Credit Extensions during the term
          of
          this Agreement and any extensions, renewals, supplements or restatements
          of this
          Agreement.

         

        12.2  Governmental
          Regulation.
          Anything contained in this Agreement to the contrary notwithstanding, neither
          the LC Issuer nor any Lender will be obligated to extend credit to the
          Borrowers
          in violation of any limitation or prohibition provided by any applicable
          statute
          or regulation.

         

        12.3  Headings.
          Section
          headings in the Loan Documents are for convenience of reference only, and
          will
          not govern the interpretation of any of the provisions of the Loan
          Documents.

         

        12.4  Entire
          Agreement.
          The
          Loan Documents embody the entire agreement and understanding among the
          Borrowers, the Administrative Agent, the LC Issuer and the Lenders and
          supersede
          all prior agreements and understandings among the Borrowers, the Administrative
          Agent, the LC Issuer and the Lenders relating to the subject matter of
          the Loan
          Documents other than the Administrative Agent Fee Letter, all of which
          will
          survive and remain in full force and effect during the term of this
          Agreement.

         

        12.5  Several
          Obligations; Benefits of this Agreement.
          The
          respective obligations of the Lenders hereunder are several and not joint
          and no
          Lender will be the partner or Administrative Agent of any other (except
          to the
          extent to which the Administrative Agent is authorized to act in such capacity).
          The failure of a Lender to perform any of its obligations hereunder will
          not
          relieve any other Lender from any of its obligations hereunder. This Agreement
          will not be construed so as to confer any right or benefit on any Person
          other
          than the parties to this Agreement and their respective successors and
          assigns.

         

        12.6  Expenses;
          Indemnification.

         

        (i) The
          Borrowers will promptly reimburse the Administrative Agent and the Syndication
          Agent for any filing and recording fees, reasonable costs and out-of-pocket
          expenses (including reasonable attorneys' fees, time charges and expenses
          advanced of attorneys for the Administrative Agent or for any of the Lenders)
          paid or incurred by the Administrative Agent or the Syndication Agent in
          connection with the preparation, negotiation, execution, closing, delivery,
          syndication, review, amendment, waiver, consent or modification, refinancing,
          Lien perfection, administration, collection and enforcement of the Loan
          Documents, regardless of 

         

        
          
            59

          

          
            
            

            
            

          

          whether
            or not the transactions provided for in this Agreement are eventually
            closed and
            regardless of whether or not any or all sums evidenced by the Notes are
            advanced
            to the Borrowers by the Lenders. 

        

         

        (ii)
           The
          Borrowers hereby also agree to indemnify against and, where applicable,
          reimburse for, the Administrative Agent, the Syndication Agent, the LC
          Issuer
          and each Lender, its directors, officers and employees, all losses, claims,
          damages, penalties, judgments, liabilities and expenses (including, without
          limitation, the prompt reimbursement of all legal fees and expenses of
          attorneys
          for the Administrative Agent, the Syndication Agent, the LC Issuer or any
          of the
          Lenders in connection with (i) restructure as a part of loan work out or
          special
          asset modification or fees and expenses from enforcement or collection
          actions
          or proceedings, and (ii) collection and enforcement actions or proceedings,
          including litigation or preparation therefor whether or not the Administrative
          Agent, the Syndication Agent, the LC Issuer or any Lender is a party to
          such
          litigation) which any of them may pay or incur in good faith as a result
          of this
          Agreement, the other Loan Documents, the transactions contemplated by the
          Loan
          Documents except to the extent that they are determined in a final
          non-appealable judgment by a court of competent jurisdiction to have resulted
          from the gross negligence or willful misconduct of the party seeking
          indemnification. 

         

        The
          obligations of the Borrowers under this Section 12.6 will survive the
          termination of this Agreement.

         

        12.7  Severability
          of Provisions.
          Any
          provision in any Loan Document that is held to be inoperative, unenforceable,
          or
          invalid in any jurisdiction will, as to that jurisdiction, be inoperative,
          unenforceable, or invalid without affecting the remaining provisions in
          that
          jurisdiction or the operation, enforceability, or validity of that provision
          in
          any other jurisdiction. The provisions of all Loan Documents are
          severable.

         

        12.8  Nonliability
          of Lenders.
          The
          relationship between the Borrowers on the one hand and the Lenders, the
          LC
          Issuer and the Administrative Agent on the other hand will, to the extent
          that
          relationship is the subject of this Agreement, be solely that of borrowers
          and
          lenders. Neither the Administrative Agent, the Syndication Agent, the LC
          Issuer
          nor any Lender will have any fiduciary responsibilities to the Credit Parties.
          Neither the Administrative Agent, the Syndication Agent, the LC Issuer
          nor any
          Lender undertakes any responsibility to the Credit Parties to review or
          inform
          the Credit Parties of any matter in connection with any phase of the Credit
          Parties' business or operations. The Borrowers agree that neither the
          Administrative Agent, the Syndication Agent, the LC Issuer nor any Lender
          will
          have liability to the Credit Parties (whether sounding in tort, contract
          or
          otherwise) for losses suffered by the Credit Parties in connection with,
          arising
          out of, or in any way related to, the transactions contemplated and the
          relationship established by the Loan Documents, or any act, omission or
          event
          occurring in connection therewith, unless it is determined in a final
          non-appealable judgment by a court of competent jurisdiction that such
          losses
          resulted from the gross negligence or willful misconduct of the party from
          which
          recovery is sought. Neither the Administrative Agent, the Syndication Agent,
          the
          LC Issuer nor any Lender will have any liability with respect to, and the
          Borrowers hereby waive, release and 

         

        
          
            60

          

          
            
            

            
            

          

          
            
            
agree
            not
            to sue for, any special, indirect or consequential damages suffered by
            the
            Credit Parties in connection with, arising out of, or in any way related
            to the
            Loan Documents or the transactions contemplated thereby.

        

         

        12.9  Confidentiality.
          Each
          Lender agrees to hold as confidential any information which it may receive
          from
          the Borrowers pursuant to this Agreement in confidence, except for disclosure
          (i) to its Affiliates and to other Lenders and their respective Affiliates,
          (ii)
          to legal counsel, accountants, and other professional advisors to such
          Lender or
          to a Transferee, (iii) to regulatory officials, (iv) to any Person as requested
          pursuant to or as required by law, regulation, or legal process, (v) to
          any
          Person in connection with any legal proceeding to which such Lender is
          a party,
          (vi) to such Lender's direct or indirect contractual counterparties in
          swap
          agreements or to legal counsel, accountants and other professional advisors
          to
          such counterparties, (vii) permitted by Section 14.4, (viii) to rating
          agencies
          if requested or required by such agencies in connection with a rating relating
          to the Advances, and (ix) of information that the Credit Parties have made
          available to the general public.

         

        12.10  Disclosure.
          The
          Borrowers and each Lender hereby acknowledge and agree that BOk and/or
          its
          Affiliates from time to time may hold investments in, make other loans
          to or
          have other relationships with the Borrowers and/or their
          Subsidiaries.

         

        12.11  Place
          of Payment.
          All
          amounts to be paid by the Borrowers or the Subsidiary Guarantors under
          this
          Agreement will be paid in immediately available funds to the Administrative
          Agent at its principal banking offices at Bank of Oklahoma Tower, One Williams
          Center, Tulsa, Oklahoma 74192, Attention: Energy Department - 8th Floor,
          or at
          such other place as the Administrative Agent or the Required Lenders will
          notify
          Unit in writing. If any interest, principal or other payment falls due
          on a date
          other than a Business Day, then (unless otherwise provided in this Agreement)
          such due date will be extended to the next succeeding Business Day, and
          such
          extension of time will in such case be included in computing interest,
          if any,
          in connection with such payment.

         

        12.12  Interest.
          It is
          the intention of the parties to this Agreement that the Lenders conform
          strictly
          to usury laws applicable to it. Accordingly, if the transactions contemplated
          by
          this Agreement would be usurious as to a Lender under laws applicable to
          it
          (including the laws of the United States of America or any other jurisdiction
          whose laws may be mandatorily applicable to Lenders notwithstanding the
          other
          provisions of this Agreement), then, in that event, notwithstanding anything
          to
          the contrary in any of the Loan Documents or any agreement entered into
          in
          connection with or as security for the Notes, it is agreed as follows:
          

         

        (i)
           the
          aggregate of all consideration which constitutes interest under law applicable
          to Lenders that is contracted for, taken, reserved, charged or received
          by
          Lenders under any of the Loan Documents or agreements or otherwise in connection
          with the Notes will under no circumstances exceed the Highest Lawful Rate
          allowed by such applicable law, and any excess will be canceled automatically
          and if theretofore paid will be credited by the Administrative Agent or
          the
          Lenders on the principal amount of the Obligations (or, to the extent that
          the
          principal amount of the Obligations will have been or would thereby be
          paid in
          full, refunded by Administrative Agent or the Lenders to the Borrowers);
          and


         

        
          
            61

          

          
            
            

            
            

          

          
            
            

          

        

        (ii)
           in
          the
          event that the maturity of any of the Notes is accelerated by, because
          of or
          resulting from an Event of Default under this Agreement or otherwise, or
          in the
          event of any required or permitted prepayment, then such consideration
          that
          constitutes interest under law applicable to Administrative Agent or the
          Lenders
          may never include more than the maximum amount allowed by such applicable
          law,
          and excess interest, if any, provided for in this Agreement or otherwise
          will be
          canceled automatically by Lenders as of the date of such acceleration or
          prepayment and, if theretofore paid, will be credited by Administrative
          Agent or
          the Lenders on the principal amount of the Obligations (or, to the extent
          that
          the principal amount of the Obligations will have been or would thereby
          be paid
          in full, refunded by Lenders to the Borrowers). 

         

        All
          sums
          paid or agreed to be paid to Administrative Agent or the Lenders for the
          use,
          forbearance or detention of sums due under this Agreement will, to the
          extent
          permitted by law applicable to Administrative Agent and/or the Lenders,
          be
          amortized, prorated, allocated and spread throughout the full term of the
          Loans
          evidenced by the Notes until payment in full so that the rate or amount
          of
          interest on account of any Loans under this Agreement does not exceed the
          Highest Lawful Rate allowed by such applicable law. If at any time and
          from time
          to time (i) the amount of interest payable to Lenders on any date will
          be
          computed at the highest lawful rate applicable to Lenders pursuant to this
          Section 12.12; and (ii) in respect of any subsequent interest computation
          period
          the amount of interest otherwise payable to Lenders would be less than
          the
          amount of interest payable to Lenders computed at the highest lawful rate
          applicable to such Lenders, then the amount of interest payable to Lenders
          regarding such subsequent interest computation period will continue to
          be
          computed at the Highest Lawful Rate applicable to Lenders until the total
          amount
          of interest payable to Lenders equals the total amount of interest which
          would
          have been payable to Lenders if the total amount of interest had been computed
          without giving effect to this Section 12.12. 

         

        None
          of
          the terms and provisions contained in this Agreement or in any other Loan
          Document which directly or indirectly relate to interest will ever be construed
          without reference to this Section 12.12, or be construed to create a contract
          to
          pay for the use, forbearance or detention of money at an interest rate
          in excess
          of the Highest Lawful Rate.

         

        12.13  Automatic
          Debit of Borrowers’ Operating Account.
          Upon
          Borrowers' failure to pay all such costs and expenses owed by Borrowers
          under
          Section 12.6 of this Agreement within thirty (30) days of the Administrative
          Agent's submission of invoices therefore, the Administrative Agent will
          pay such
          costs and expenses by debit to the operating account of Borrowers with
          the
          Administrative Agent without further or other notice to Borrowers.

         

        12.14  Exceptions
          to Covenants.
          The
          Borrowers are not permitted to take any action or fail to take any action
          which
          is permitted as an exception to any of the covenants contained in this
          Agreement
          or which is within the permissible limits of any of the covenants contained
          in
          this Agreement if such action or omission would result in the breach of
          any
          other covenant contained in this Agreement.

         

        12.15  Conflict
          with Other Loan Documents.
          To the
          extent the terms and provisions of any of the other Loan Documents are
          in
          conflict with the terms and provisions hereof, this Agreement will be deemed
          controlling.

         

        
          
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        12.16  Lost
          Documents.
          On
          receipt of an affidavit of an officer of the Administrative Agent as to
          the
          loss, theft, destruction or mutilation of the Notes or Loan Documents which is
          not of public record, and, in the case of any mutilation, on the surrender
          and
          cancellation of the Notes or Loan Documents, the Borrowers or any Subsidiary
          Guarantors will issue, in lieu thereof, a replacement Note(s) or other
          Loan
          Documents in the same principal amount thereof (in the case of any of the
          Notes)
          and otherwise of like tenor.

         

        ARTICLE
          XIII

        THE
          ADMINISTRATIVE AGENT

         

        13.1  Appointment;
          Nature of Relationship.
          BOk is
          hereby appointed by each of the Lenders as its contractual representative
          (herein referred to as the "Administrative Agent") hereunder and under
          each
          other Loan Document, and each of the Lenders irrevocably authorizes the
          Administrative Agent to act as the contractual representative of such Lender
          with the rights and duties expressly set forth herein and in the other
          Loan
          Documents. The Administrative Agent agrees to act as such contractual
          representative upon the express conditions contained in this Article XIII.
          Notwithstanding the use of the defined term "Administrative Agent," it
          is
          expressly understood and agreed that the Administrative Agent will not
          have any
          fiduciary responsibilities to any Lender by reason of this Agreement or
          any
          other Loan Document and that the Administrative Agent is merely acting
          as the
          contractual representative of the Lenders with only those duties as are
          expressly set forth in this Agreement and the other Loan Documents. In
          its
          capacity as the Lenders' contractual representative, the Administrative
          Agent
          (i) does not hereby assume any fiduciary duties to any of the Lenders,
          (ii) is a
          "representative" of the Lenders within the meaning of the term "secured
          party"
          as defined in the Oklahoma Uniform Commercial Code and (iii) is acting
          as an
          independent contractor, the rights and duties of which are limited to those
          expressly set forth in this Agreement and the other Loan Documents. Each
          of the
          Lenders hereby agrees to assert no claim against the Administrative Agent
          on any
          agency theory or any other theory of liability for breach of fiduciary
          duty, all
          of which claims each Lender hereby waives.

         

        13.2  Powers.
          The
          Administrative Agent will have and may exercise such powers under the Loan
          Documents as are specifically delegated to the Administrative Agent by
          the terms
          of each thereof, together with such powers as are reasonably incidental
          thereto.
          The Administrative Agent has no implied duties to the Lenders, or any obligation
          to the Lenders to take any action thereunder except any action specifically
          provided by the Loan Documents to be taken by the Administrative
          Agent.

         

        13.3  General
          Immunity.
          Neither
          the Administrative Agent nor any of its directors, officers or employees
          will be
          liable to the Credit Parties, the Lenders or any Lender for any action
          taken or
          omitted to be taken by it or them hereunder or under any other Loan Document
          or
          in connection herewith or therewith except to the extent such action or
          inaction
          is determined in a final non-appealable judgment by a court of competent
          jurisdiction to have arisen from the gross negligence or willful misconduct
          of
          such Person provided that nothing in this Section 13.3 is intended to impair
          or
          otherwise limit (i) the rights of the Credit Parties to make claims against
          the
          LC Issuer for damages as contemplated by either proviso (ii) to the first
          sentence of Section 2.19.6 or proviso (y) to the penultimate sentence of
          Section
          2.19.9 or (ii) 

         

        
          
            63

          

          
            
            

            
            

          

          
            
            
the
            liabilities of the LC Issuer or the Administrative Agent to the Credit
            Parties
            based on a standard of care otherwise expressly designated or stipulated
            to in
            other provisions of this Agreement. 

        

         

        13.4  No
          Responsibility for Loans, Recitals.
          Neither
          the Administrative Agent nor any of its directors, officers or employees
          will be
          responsible for or have any duty to ascertain, inquire into, or verify
          (a) any
          statement, warranty or representation made in connection with any Loan
          Document
          or any borrowing hereunder; (b) the performance or observance of any of
          the
          covenants or agreements of any obligor under any Loan Document, including,
          without limitation, any agreement by an obligor to furnish information
          directly
          to each Lender; (c) the satisfaction of any condition specified in Article
          IV,
          except receipt of items required to be delivered solely to the Administrative
          Agent; (d) the existence or possible existence of any Default; (e) the
          validity,
          enforceability, effectiveness, sufficiency or genuineness of any Loan Document
          or any other instrument or writing furnished in connection therewith; (f)
          the
          value, sufficiency, creation, perfection or priority of any Lien in any
          collateral security; or (g) the financial condition of the Credit Parties
          or any
          Subsidiary Guarantor of any of the Obligations or of any of the Credit
          Parties'
          or any such Subsidiary Guarantor 's respective Subsidiaries. The Administrative
          Agent has no duty to disclose to the Lenders information that is not required
          to
          be furnished by the Credit Parties to the Administrative Agent at such
          time, but
          is voluntarily furnished by the Credit Parties to the Administrative Agent
          (either in its capacity as Administrative Agent or in its individual
          capacity).

         

        13.5  Action
          on Instructions of Lenders.
          The
          Administrative Agent will in all cases be fully protected in acting, or
          in
          refraining from acting, hereunder and under any other Loan Document in
          accordance with written instructions signed by the Required Lenders, and
          such
          instructions and any action taken or failure to act pursuant thereto will
          be
          binding on all of the Lenders. The Lenders hereby acknowledge that the
          Administrative Agent will be under no duty to take any discretionary action
          permitted to be taken by it pursuant to the provisions of this Agreement
          or any
          other Loan Document unless it is requested in writing to do so by the Required
          Lenders. The Administrative Agent will be fully justified in failing or
          refusing
          to take any action hereunder and under any other Loan Document unless it
          is
          first indemnified to its satisfaction by the Lenders pro rata against any
          and
          all liability, cost and expense that it may incur by reason of taking or
          continuing to take any such action.

         

        13.6  Employment
          of Administrative Agents; Counsel; Reliance.
          The
          Administrative Agent may execute any of its duties as Administrative Agent
          hereunder and under any other Loan Document by or through employees,
          Administrative Agents, and attorneys-in-fact and is not answerable to the
          Lenders, except as to money or securities received by it or its authorized
          Administrative Agents, for the default or misconduct of any such Administrative
          Agents or attorneys-in-fact selected by it with reasonable care. The
          Administrative Agent will be entitled to advice of counsel concerning the
          contractual arrangement between the Administrative Agent and the Lenders
          and all
          matters pertaining to the Administrative Agent's duties hereunder and under
          any
          other Loan Document. The Administrative Agent will be entitled to rely
          upon any
          Note, notice, consent, certificate, affidavit, letter, telegram, statement,
          paper or document believed by it to be genuine and correct and to have
          been
          signed or sent by the proper person or persons, and, in respect to legal
          matters, upon the opinion of counsel selected by the Administrative Agent,
          which
          counsel may be employees of the Administrative Agent.

         

        
          
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        13.7  Administrative
          Agent's Reimbursement and Indemnification.
          The
          Lenders agree to reimburse and indemnify the Administrative Agent ratably
          in
          proportion to their respective Commitments (or, if the Commitments have
          been
          terminated, in proportion to their Commitments immediately prior to such
          termination) (i) for any amounts not reimbursed by the Borrowers for which
          the
          Administrative Agent is entitled to reimbursement by the Borrowers under
          the
          Loan Documents, (ii) for any other expenses incurred by the Administrative
          Agent
          on behalf of the Lenders, in connection with the preparation, execution,
          delivery, administration and enforcement of the Loan Documents (including,
          without limitation, for any expenses incurred by the Administrative Agent
          in
          connection with any dispute between the Administrative Agent and any Lender
          or
          between two or more of the Lenders) and (iii) for any liabilities, obligations,
          losses, damages, penalties, actions, judgments, suits, costs, expenses
          or
          disbursements of any kind and nature whatsoever which may be imposed on,
          incurred by or asserted against the Administrative Agent in any way relating
          to
          or arising out of the Loan Documents or any other document delivered in
          connection therewith or the transactions contemplated thereby (including,
          without limitation, for any such amounts incurred by or asserted against
          the
          Administrative Agent in connection with any dispute between the Administrative
          Agent and any Lender or between two or more of the Lenders), or the enforcement
          of any of the terms of the Loan Documents or of any such other documents,
          provided that (i) no Lender will be liable for any of the foregoing to
          the
          extent any of the foregoing is found in a final non-appealable judgment
          by a
          court of competent jurisdiction to have resulted from the gross negligence
          or
          willful misconduct of the Administrative Agent and (ii) any indemnification
          required pursuant to Section 3.3(iv) will, notwithstanding the provisions
          of
          this Section 13.7, be paid by the relevant Lender in accordance with the
          provisions thereof. The obligations of the Lenders under this Section 13.7
          will
          survive payment of the Obligations and termination of this
          Agreement.

         

        13.8  Notice
          of Default.
          The
          Administrative Agent will not be deemed to have knowledge or notice of
          the
          occurrence of any Default under this Agreement unless the Administrative
          Agent
          has received written notice from a Lender or the Borrowers referring to
          this
          Agreement describing such Default and stating that such notice is a "notice
          of
          default." In the event that the Administrative Agent receives such a notice,
          the
          Administrative Agent will give prompt notice thereof to the
          Lenders.

         

        13.9  Rights
          as a Lender.
          In the
          event the Administrative Agent is a Lender, the Administrative Agent will
          have
          the same rights and powers hereunder and under any other Loan Document
          with
          respect to its Commitment and its Loans as any Lender and may exercise
          the same
          as though it were not the Administrative Agent, and the term "Lender" or
          "Lenders" will, at any time when the Administrative Agent is a Lender,
          unless
          the context otherwise indicates, include the Administrative Agent in its
          individual capacity. The Administrative Agent and its Affiliates may accept
          deposits from, lend money to, and generally engage in any kind of trust,
          debt,
          equity or other transaction, in addition to those contemplated by this
          Agreement
          or any other Loan Document, with the Credit Parties in which the Credit
          Parties
          are not restricted hereby from engaging with any other Person.

         

        13.10  Lender
          Credit Decision.
          Each
          Lender acknowledges that it has, independently and without reliance upon
          the
          Administrative Agent, the Syndication Agent or any other Lender and based
          on the
          financial statements prepared by the Credit Parties and such other documents
          and
          information as it has deemed appropriate, made its own 

         

        
          
            65

          

          
            
            

            
            

          

          
            
            
credit
            analysis and decision to enter into this Agreement and the other Loan
            Documents.
            Each Lender also acknowledges that it will, independently and without
            reliance
            upon the Administrative Agent, the Syndication Agent or any other Lender
            and
            based on such documents and information as it deems appropriate at the
            time,
            continue to make its own credit decisions in taking or not taking action
            under
            this Agreement and the other Loan Documents.

        

         

        13.11  Successor
          Administrative Agent.
          The
          Administrative Agent may resign at any time by giving written notice thereof
          to
          the Lenders and Unit, such resignation to be effective upon the appointment
          of a
          successor Administrative Agent or, if no successor Administrative Agent
          has been
          appointed, 45 days after the retiring Administrative Agent gives notice
          of its
          intention to resign. The Administrative Agent may be removed at any time
          with or
          without cause by written notice received by the Administrative Agent from
          the
          Required Lenders, such removal to be effective on the date specified by
          the
          Required Lenders. Upon any such resignation or removal, the Required Lenders
          will have the right to appoint, on behalf of the Credit Parties and the
          Lenders,
          a successor Administrative Agent. If no successor Administrative Agent
          will have
          been so appointed by the Required Lenders within thirty days after the
          resigning
          Administrative Agent's giving notice of its intention to resign, then the
          resigning Administrative Agent may appoint, on behalf of the Credit Parties
          and
          the Lenders, a successor Administrative Agent. Notwithstanding the previous
          sentence, the Administrative Agent may at any time without the consent
          of the
          Credit Parties or any Lender, appoint any of its Affiliates which is a
          commercial bank as a successor Administrative Agent hereunder. If the
          Administrative Agent has resigned or been removed and no successor
          Administrative Agent has been appointed, the Lenders may perform all the
          duties
          of the Administrative Agent hereunder and the Borrowers will make all payments
          in respect of the Obligations to the applicable Lender and for all other
          purposes will deal directly with the Lenders. No successor Administrative
          Agent
          will be deemed to be appointed hereunder until such successor Administrative
          Agent has accepted the appointment. Any such successor Administrative Agent
          will
          be a commercial bank having capital and retained earnings of at least
          $100,000,000. Upon the acceptance of any appointment as Administrative
          Agent
          hereunder by a successor Administrative Agent, such successor Administrative
          Agent will thereupon succeed to and become vested with all the rights,
          powers,
          privileges and duties of the resigning or removed Administrative Agent.
          Upon the
          effectiveness of the resignation or removal of the Administrative Agent,
          the
          resigning or removed Administrative Agent will be discharged from its duties
          and
          obligations hereunder and under the Loan Documents. After the effectiveness
          of
          the resignation or removal of an Administrative Agent, the provisions of
          this
          Article XIII will continue in effect for the benefit of such Administrative
          Agent in respect of any actions taken or omitted to be taken by it while
          it was
          acting as the Administrative Agent hereunder and under the other Loan Documents.
          

         

        13.12  Syndication
          Agent.
          No
          Lender identified in this Agreement as the Syndication Agent will have
          any
          right, power, obligation, liability, responsibility or duty under this
          Agreement
          other than those applicable to all Lenders as such. Without limiting the
          foregoing, no Lender will have or be deemed to have a fiduciary relationship
          with any other Lender. Each Lender hereby makes the same acknowledgments
          with
          respect to such Lenders as it makes with respect to the Administrative
          Agent in
          Section 13.10.

         

        13.13  Delegation
          to Affiliates.
          The
          Borrowers and the Lenders agree that the Administrative Agent may delegate
          any
          of its duties under this Agreement to any of its Affiliates. Any Affiliate
          of
          the Administrative Agent which 

         

        
          
            66

          

          
            
            

            
            

          

          
            
            
performs
            duties in connection with this Agreement will be entitled to the same
            benefits
            of the indemnification, waiver and other protective provisions to which
            the
            Administrative Agent is entitled under Articles XII and XIII.

        

         

        ARTICLE
          XIV

        BENEFIT
          OF AGREEMENT; ASSIGNMENTS; PARTICIPATIONS

         

        14.1  Successors
          and Assigns.
          The
          terms and provisions of the Loan Documents will be binding upon and inure
          to the
          benefit of the Credit Parties which are parties thereto and the Lenders
          and
          their respective successors and assigns permitted hereby, except that (i)
          the
          Credit Parties will not have the right to assign their rights or obligations
          under the Loan Documents to which they are parties without the prior written
          consent of each Lender, (ii) any assignment by any Lender must be made
          in
          compliance with Section 14.3, and (iii) any transfer by participation must
          be
          made in compliance with Section 14.2. Any attempted assignment or transfer
          by
          any party not made in compliance with this Section 14.1 will be null and
          void,
          unless such attempted assignment or transfer is treated as a participation
          in
          accordance with Section 14.3.2. The parties to this Agreement acknowledge
          that
          clause (ii) of this Section 14.1 relates only to absolute assignments and
          this
          Section 14.1 does not prohibit assignments creating security interests,
          including, without limitation, any pledge or assignment by any Lender of
          all or
          any portion of its rights under this Agreement and any Note to a Federal
          Reserve
          Bank; provided, however, that no such pledge or assignment creating a security
          interest will release the transferor Lender from its obligations hereunder
          unless and until the parties thereto have complied with the provisions
          of
          Section 14.3. The Administrative Agent may treat the Person which made
          any Loan
          or which holds any Note as the owner thereof for all purposes hereof unless
          and
          until such Person complies with Section 14.3; provided, however, that the
          Administrative Agent may in its discretion (but will not be required to)
          follow
          instructions from the Person which made any Loan or which holds any Note
          to
          direct payments relating to such Loan or Note to another Person. Any assignee
          of
          the rights to any Loan or any Note agrees by acceptance of such assignment
          to be
          bound by all the terms and provisions of the Loan Documents. Any request,
          authority or consent of any Person, who at the time of making such request
          or
          giving such authority or consent is the owner of the rights to any Loan
          (whether
          or not a Note has been issued in evidence thereof), will be conclusive
          and
          binding on any subsequent holder or assignee of the rights to such
          Loan.

         

        14.2  Participations.

         

        14.2.1.  Permitted
          Participants; Effect.
          Any
          Lender may, in the ordinary course of its business and in accordance with
          applicable law, at any time upon obtaining the prior written consent of
          Unit
          sell to one or more banks or other entities ("Participants") participating
          interests in any Outstanding Credit Exposure of such Lender, any Note held
          by
          such Lender, any Commitment of such Lender or any other interest of such
          Lender
          under the Loan Documents. In the event of any such sale by a Lender of
          participating interests to a Participant, such Lender's obligations under
          the
          Loan Documents will remain unchanged, such Lender will remain solely responsible
          to the other parties hereto for the performance of such obligations, such
          Lender
          will remain the owner of its Outstanding Credit Exposure and the holder
          of any
          Note issued to it in evidence thereof for all purposes under the Loan Documents,
          all amounts payable by the Borrowers under this Agreement will 

         

        
          
            67

          

          
            
            

            
            

          

          
            
            
be
            determined as if such Lender had not sold such participating interests,
            and the
            Borrowers and the Administrative Agent will continue to deal solely and
            directly
            with such Lender in connection with such Lender's rights and obligations
            under
            the Loan Documents.

        

         

        14.2.2.  Voting
          Rights.
          Each
          Lender will retain the sole right to approve, without the consent of any
          Participant, any amendment, modification or waiver of any provision of
          the Loan
          Documents other than any amendment, modification or waiver with respect
          to any
          Credit Extension or Commitment in which such Participant has an interest
          which
          would require consent of all of the Lenders pursuant to the terms of Section
          11.2 or of any other Loan Document.

         

        14.2.3.  Benefit
          of Certain Provisions.
          The
          Borrowers agree that each Participant will be deemed to have the right
          of setoff
          provided in Section 6.11 in respect of its participating interest in amounts
          owing under the Loan Documents to the same extent as if the amount of its
          participating interest were owing directly to it as a Lender under the
          Loan
          Documents, provided that each Lender will retain the right of setoff provided
          in
          Section 6.11 with respect to the amount of participating interests sold
          to each
          Participant. The Lenders agree to share with each Participant, and each
          Participant, by exercising the right of setoff provided in Section 6.11,
          agrees
          to share with each Lender, any amount received pursuant to the exercise
          of its
          right of setoff, such amounts to be shared in accordance with Section 6.11(c)
          as
          if each Participant were a Lender. The Borrowers further agree that each
          Participant will be entitled to the benefits of Sections 3.1, 3.2, 3.4
          and 3.5
          to the same extent as if it were a Lender and had acquired its interest
          by
          assignment pursuant to Section 14.3, provided that (i) a Participant will
          not be
          entitled to receive any greater payment under Section 3.1, 3.2 or 3.5 than
          the
          Lender who sold the participating interest to such Participant would have
          received had it retained such interest for its own account, unless the
          sale of
          such interest to such Participant is made with the prior written consent
          of the
          Borrowers, and (ii) any Participant not incorporated under the laws of
          the
          United States of America or any State thereof agrees to comply with the
          provisions of Section 3.3 to the same extent as if it were a
          Lender.

         

        14.3  Assignments.

         

        14.3.1.  Permitted
          Assignments.
          Any
          Lender may, in the ordinary course of its business and in accordance with
          applicable law, at any time assign to one or more banks or other entities
          ("Purchasers") all or any part of its rights and obligations under the
          Loan
          Documents. Such assignment will be substantially in the form of Exhibit
          C or in
          such other form as may be agreed to by the parties thereto. The consent
          of Unit,
          the Administrative Agent and the LC Issuer will be required prior to an
          assignment becoming effective with respect to a Purchaser which is not
          a Lender
          or an Affiliate thereof; provided, however, that if a Default has occurred
          and
          is continuing, the consent of the Unit will not be required. Such consent
          of
          Unit will not be unreasonably withheld or delayed. Each such assignment
          with
          respect to a Purchaser which is not a Lender or an Affiliate thereof will
          (unless each of the Credit Parties and the Administrative Agent otherwise
          consent) be in an amount not less than the lesser of (i) $10,000,000 or
          (ii) the
          remaining amount of the assigning Lender's 

         

        
          
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Commitment
            (calculated as at the date of such assignment) or outstanding Loans (if
            the
            applicable Commitment has been terminated).

        

         

        14.3.2.  Effect;
          Effective Date.
          Upon
          (i) delivery to the Administrative Agent of a notice of assignment,
          substantially in the form attached as Exhibit I to Exhibit C (a "Notice
          of
          Assignment"), together with any consents required by Section 14.3.1, and
          (ii)
          payment of a $500 fee to the Administrative Agent for processing such
          assignment, such assignment will become effective on the effective date
          specified in such Notice of Assignment. The Notice of Assignment will contain
          a
          representation by the Purchaser to the effect that none of the consideration
          used to make the purchase of the Commitment and Outstanding Credit Exposure
          under the applicable assignment agreement are "plan assets" as defined
          under
          ERISA and that the rights and interests of the Purchaser in and under the
          Loan
          Documents will not be "plan assets" under ERISA. On and after the effective
          date
          of such assignment, such Purchaser will for all purposes be a Lender to
          this
          Agreement and any other Loan Document executed by or on behalf of the Lenders
          and will have all the rights and obligations of a Lender under the Loan
          Documents, to the same extent as if it were an original party hereto, and
          no
          further consent or action by the Credit Parties, the Lenders or the
          Administrative Agent will be required to release the transferor Lender
          with
          respect to the percentage of the Aggregate Commitment and Outstanding Credit
          Exposure assigned to such Purchaser. Upon the consummation of any assignment
          to
          a Purchaser pursuant to this Section 14.3.2, the transferor Lender, the
          Administrative Agent and the Borrowers will, if the transferor Lender or
          the
          Purchaser desires that its Loans be evidenced by Notes, make appropriate
          arrangements so that new Notes or, as appropriate, replacement Notes are
          issued
          to such transferor Lender and new Notes or, as appropriate, replacement
          Notes,
          are issued to such Purchaser, in each case in principal amounts reflecting
          their
          respective Commitments, as adjusted pursuant to such assignment.

         

        14.3.3.  Register.
          The
          Administrative Agent, acting solely for this purpose as an Administrative
          Agent
          of the Borrowers, will maintain at its main banking offices in Tulsa, Oklahoma,
          a copy of each Assignment and Assumption delivered to it and a register
          for the
          recordation of the names and addresses of the Lenders, and the Commitments
          of,
          and principal amounts of the Loans owing to, each Lender pursuant to the
          terms
          hereof from time to time (the "Register"). The entries in the Register
          will be
          conclusive, and the Borrowers, the Administrative Agent and the Lenders
          may
          treat each Person whose name is recorded in the Register pursuant to the
          terms
          hereof as a Lender hereunder for all purposes of this Agreement, notwithstanding
          notice to the contrary. The Register will be available for inspection by
          the
          Borrowers and any Lender, at any reasonable time and from time to time
          upon
          reasonable prior notice.

         

        14.4  Dissemination
          of Information.
          The
          Borrowers authorize each Lender to disclose to any Participant or Purchaser
          or
          any other Person acquiring an interest in the Loan Documents by operation
          of law
          (each a "Transferee") and any prospective Transferee any and all information
          in
          such Lender's possession concerning the creditworthiness of the Credit
          Parties
          and their Subsidiaries, including without limitation any information contained
          in any reports provided to Administrative Agent; provided that each Transferee
          and prospective Transferee agrees to be bound by this Agreement.

         

        
          
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        14.5  Tax
          Treatment.
          If any
          interest in any Loan Document is transferred to any Transferee which is
          not
          incorporated under the laws of the United States or any State thereof,
          the
          transferor Lender will cause such Transferee, concurrently with the
          effectiveness of such transfer, to comply with the provisions of Section
          3.3(iv).

         

        14.6  Procedure
          for Increases and Addition of New Lenders.
          This
          Agreement permits (i) increases in existing Lenders' Commitments and (ii)
          the
          admission of new Lenders providing new Commitments, subject to the consent
          of
          the Agent and Unit, provided that neither the Aggregate Commitment nor
          the
          Maximum Credit Amount may be increased as a result of (i) or (ii) above
          without
          the consent of all Lenders. Any amendment hereto for an increase in a Lender's
          Commitment or addition of a new Lender will be in the form attached hereto
          as
          Exhibit D. Within a reasonable time after the effective date of either
          (i) or
          (ii) above, the Administrative Agent will, and is hereby authorized and
          directed
          to, revise the Lenders Schedule reflecting such increase and will distribute
          revised Lenders Schedule to each of the Lenders and Unit, and the revised
          Lenders Schedule will replace the old Lenders Schedule and become part
          of this
          Agreement. On the Business Day following any increase, all outstanding
          Alternate
          Base Rate Advances will be reallocated among the Lenders (including any
          newly
          added Lenders) in accordance with the Lenders' respective revised Pro Rata
          Shares. Eurodollar Advances will not be reallocated among the Lenders prior
          to
          the expiration of the applicable Interest Period in effect at the time
          of any
          increase.

         

        ARTICLE
          XV

        NOTICES/CONSENTS

         

        15.1  Notices.
          Except
          as otherwise permitted by Section 2.9 with respect to Borrowing Notices,
          all
          notices, requests and other communications to any party hereunder will
          be in
          writing (including facsimile transmission or similar writing) and will
          be given
          to such party: (x) in the case of the Borrowers, the Administrative Agent
          and
          existing Lenders signatory parties hereto, at its address or facsimile
          number
          set forth on the signature pages hereof, (y) in the case of any future
          or
          additional Lender, at its address or facsimile number set forth on the
          Lenders
          Schedule or the executed Exhibit D pertaining thereto or (z) in the case
          of any
          party, at such other address or facsimile number as such party may hereafter
          specify for the purpose by notice to the Administrative Agent and the Borrowers
          in accordance with the provisions of this Section 15.1. Each such notice,
          request or other communication will be effective (i) if given by facsimile
          transmission, when transmitted to the facsimile number specified in this
          Section
          and confirmation of receipt is received, (ii) if given by mail, 72 hours
          after
          such communication is deposited in the mails with first class postage prepaid,
          addressed as aforesaid, or (iii) if given by any other means, when delivered
          at
          the address specified in this Section; provided that notices to the
          Administrative Agent under Article II will not be effective until
          received.

         

        15.2  Change
          of Address.
          The
          Borrowers, the Administrative Agent and any Lender (i) may each change
          the
          address for service of notice upon it by a notice in writing to the other
          parties hereto and (ii) will give such a notice if its address will
          change.

         

        15.3  Consent
          to Amendments.
          This
          Agreement and any of the other Loan Documents may be amended, and the Borrowers
          may take any action herein prohibited, or omit to perform any act herein
          required to be performed by it, if the Borrowers will obtain the written
          consent
          to such amendment, action or omission to act, of the Administrative Agent
          

         

        
          
            70

          

          
            
            

            
            

          

          
            
            
and
            the
            Lenders. Each holder of any of the Notes at the time or thereafter outstanding
            will be bound by any consent authorized by this Section 15.3, whether
            or not the
            Notes will have been marked to indicate such consent, but any Notes issued
            thereafter may bear a notation referring to any such consent. No course
            of
            dealing between the Credit Parties and any holder of any of the Notes
            nor any
            delay in exercising any rights hereunder or under the Notes will operate
            as a
            waiver of any rights of any holder of any of the Notes. As used herein
            and in
            the Notes, the term "this Agreement" and references thereto will mean
            this
            Agreement as it may from time to time be amended, modified or
            supplemented.

        

         

        15.4  USA
          PATRIOT Act Notice.
          IMPORTANT
          INFORMATION ABOUT PROCEDURES FOR OPENING A NEW ACCOUNT.
          To help
          the government fight the funding of terrorism and money laundering activities,
          federal law requires all financial institutions to obtain, verify, and
          record
          information that identifies each person or entity that opens an account,
          including any deposit account, treasury management account, loan, other
          extension of credit, or other financial services product. What this means
          for
          borrowers: When a borrower opens an account, the Bank will ask for the
          borrower's name, residential address, tax identification number, and other
          information that will allow the Bank to identify the borrower, including
          the
          borrower's date of birth if the borrower is an individual. The Bank may
          also
          ask, if the borrower is an individual, to see the borrower's driver's license
          or
          other identifying documents, and, if the borrower is not an individual,
          to see
          the borrower's legal organizational documents or other identifying documents.
          The Bank will verify and record the information the Bank obtains from the
          borrower pursuant to the USA PATRIOT Act, and will maintain and retain
          that
          record in accordance with the regulations promulgated under the USA PATRIOT
          Act.

         

        ARTICLE
          XVI

        COUNTERPARTS

         

        This
          Agreement may be executed in any number of counterparts, all of which taken
          together will constitute one agreement, and any of the parties hereto may
          execute this Agreement by signing any such counterpart. This Agreement
          will be
          effective when it has been executed by the Borrowers, the Administrative
          Agent,
          the LC Issuer and the Lenders and each party has notified the Administrative
          Agent by facsimile transmission or electronic transmission (e-mail) that
          it has
          taken such action. All closing documents will be furnished to the Administrative
          Agent with sufficient counterparts so that the Administrative Agent may
          furnish
          one to each of the Lenders.

         

        ARTICLE
          XVII

        CHOICE
          OF LAW; CONSENT TO JURISDICTION; WAIVER OF JURY TRIAL

         

        17.1  CHOICE
          OF LAW.
          THE
          LOAN DOCUMENTS (OTHER THAN THOSE CONTAINING A CONTRARY EXPRESS CHOICE OF
          LAW
          PROVISION) WILL BE CONSTRUED IN ACCORDANCE WITH THE INTERNAL LAWS OF THE
          STATE
          OF OKLAHOMA, BUT GIVING EFFECT TO FEDERAL LAWS APPLICABLE TO NATIONAL BANKS
          AND
          WILL BE DEEMED TO HAVE BEEN MADE OR INCURRED UNDER THE LAWS OF THE STATE
          OF
          OKLAHOMA EXCEPT ONLY WHERE THE APPLICABLE REMEDIAL OR PROCEDURAL LAWS OF
          OTHER
          JURISDICTIONS IN 

         

        
          
            71

          

          
            
            

            
            

          

          
            
            
WHICH
            PORTIONS OF THE COLLATERAL ARE SITUATED ARE APPLICABLE
            THERETO.

        

         

        17.2  CONSENT
          TO JURISDICTION.
          THE
          BORROWERS, THE ADMINISTRATIVE AGENT AND LENDERS HEREBY IRREVOCABLY SUBMIT
          TO THE
          NON-EXCLUSIVE JURISDICTION OF ANY UNITED STATES FEDERAL OR OKLAHOMA STATE
          COURT
          SITTING IN TULSA, OKLAHOMA IN ANY ACTION OR PROCEEDING ARISING OUT OF OR
          RELATING TO ANY LOAN DOCUMENTS AND THE BORROWERS, THE ADMINISTRATIVE AGENT
          AND
          LENDERS HEREBY IRREVOCABLY AGREES THAT ALL CLAIMS IN RESPECT OF SUCH ACTION
          OR
          PROCEEDING MAY BE HEARD AND DETERMINED IN ANY SUCH COURT AND IRREVOCABLY
          WAIVES
          ANY OBJECTION IT MAY NOW OR HEREAFTER HAVE AS TO THE VENUE OF ANY SUCH
          SUIT,
          ACTION OR PROCEEDING BROUGHT IN SUCH A COURT OR THAT SUCH COURT IS AN
          INCONVENIENT FORUM. NOTHING HEREIN WILL LIMIT THE RIGHT OF THE ADMINISTRATIVE
          AGENT, THE LC ISSUER OR ANY LENDER TO BRING PROCEEDINGS AGAINST THE BORROWERS
          IN
          THE COURTS OF ANY OTHER JURISDICTION.

         

        17.3  NO
          ORAL AGREEMENTS.
          THE
          LOAN DOCUMENTS EMBODY THE ENTIRE AGREEMENT AND UNDERSTANDING BETWEEN THE
          PARTIES
          AND SUPERSEDE ALL OTHER AGREEMENTS AND UNDERSTANDINGS BETWEEN SUCH PARTIES
          RELATING TO THE SUBJECT MATTER HEREOF AND THEREOF, THE LOAN DOCUMENTS REPRESENT
          THE FINAL AGREEMENT BETWEEN THE PARTIES AND MAY NOT BE CONTRADICTED BY
          EVIDENCE
          OF PRIOR, CONTEMPORANEOUS OR SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES.
          THERE
          ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN THE PARTIES.

         

        17.4  EXCULPATION
          PROVISIONS.
          EACH
          OF THE PARTIES HERETO SPECIFICALLY AGREES THAT IT HAS A DUTY TO READ THIS
          AGREEMENT, THE NOTES AND THE LOAN DOCUMENTS AND AGREES THAT IT IS CHARGED
          WITH
          NOTICE AND KNOWLEDGE OF THE TERMS OF THIS AGREEMENT, THE NOTES AND THE
          OTHER
          LOAN DOCUMENTS; THAT IT HAS IN FACT READ THIS AGREEMENT AND IS FULLY INFORMED
          AND HAS FULL NOTICE AND KNOWLEDGE OF THE TERMS, CONDITIONS AND EFFECTS
          OF THIS
          AGREEMENT; THAT IT HAS BEEN REPRESENTED BY INDEPENDENT LEGAL COUNSEL OF
          ITS
          CHOICE THROUGHOUT THE NEGOTIATIONS PRECEDING ITS EXECUTION OF THIS AGREEMENT,
          THE NOTES AND THE OTHER LOAN DOCUMENTS; AND HAS RECEIVED THE ADVICE OF
          ITS
          ATTORNEY IN ENTERING INTO THIS AGREEMENT, THE NOTES AND THE OTHER LOAN
          DOCUMENTS; AND THAT IT RECOGNIZES THAT CERTAIN OF THE TERMS OF THIS AGREEMENT,
          THE NOTES AND THE OTHER LOAN DOCUMENTS RESULT IN ONE PARTY ASSUMING THE
          LIABILITY INHERENT IN SOME ASPECTS OF THE TRANSACTION AND RELIEVING THE
          OTHER
          PARTY OF ITS RESPONSIBILITY FOR SUCH LIABILITY. EACH PARTY HERETO AGREES
          AND
          COVENANTS THAT IT WILL NOT CONTEST THE VALIDITY OR ENFORCEABILITY OF ANY
          EXCULPATORY PROVISION OF THIS AGREEMENT AND THE OTHER LOAN DOCUMENTS ON
          THE
          BASIS 

         

        
          
            72

          

          
            
            

            
            

          

          
            
            
THAT
            THE PARTY HAD NO NOTICE OR KNOWLEDGE OF SUCH PROVISION OR THAT THE PROVISION
            IS
            NOT "CONSPICUOUS." 

        

         

        17.5  WAIVER
          OF JURY TRIAL, PUNITIVE DAMAGES.
          THE
          BORROWERS, THE ADMINISTRATIVE AGENT, THE LC ISSUER AND EACH LENDER HEREBY
          WAIVE
          TRIAL BY JURY IN ANY JUDICIAL PROCEEDING INVOLVING, DIRECTLY OR INDIRECTLY,
          ANY
          MANNER (WHETHER SOUNDING IN TORT, CONTRACT OR OTHERWISE) IN ANY WAY ARISING
          OUT
          OF, RELATED TO OR CONNECTED WITH ANY LOAN DOCUMENT OR THE RELATIONSHIP
          ESTABLISHED THEREUNDER. EACH BORROWER AND EACH LENDER HEREBY FURTHER (A)
          IRREVOCABLY WAIVE, TO THE MAXIMUM EXTENT NOT PROHIBITED BY LAW, ANY RIGHT
          IT MAY
          HAVE TO CLAIM OR RECOVER IN ANY SUCH LITIGATION ANY "SPECIAL DAMAGES,"
          AS
          DEFINED BELOW, (B) CERTIFY THAT NO PARTY HERETO NOR ANY REPRESENTATIVE
          OR AGENT
          OR COUNSEL FOR ANY PARTY HERETO HAS REPRESENTED, EXPRESSLY OR OTHERWISE,
          OR
          IMPLIED THAT SUCH PARTY WOULD NOT, IN THE EVENT OF LITIGATION, SEEK TO
          ENFORCE
          THE FOREGOING WAIVERS, AND (C) ACKNOWLEDGE THAT IT HAS BEEN INDUCED TO
          ENTER
          INTO THIS AGREEMENT, THE OTHER LOAN DOCUMENTS AND THE TRANSACTIONS CONTEMPLATED
          HEREBY AND THEREBY BY, AMONG OTHER THINGS, THE MUTUAL WAIVERS AND CERTIFICATIONS
          CONTAINED IN THIS SECTION. AS USED IN THIS SECTION, "SPECIAL DAMAGES" INCLUDES
          ALL SPECIAL, CONSEQUENTIAL, EXEMPLARY, OR PUNITIVE DAMAGES (REGARDLESS
          OF HOW
          NAMED), BUT DOES NOT INCLUDE ANY PAYMENTS OR FUNDS WHICH ANY PARTY HERETO
          HAS
          EXPRESSLY PROMISED TO PAY OR DELIVER TO ANY OTHER PARTY
          HERETO.

         

        (SIGNATURE
          PAGES TO FOLLOW)

        


         


        
          
            
              
                	 	 	 


              

              


            

            73

          

          
            
            

            
            

          

          
            
            

            
            

          

        



        IN
          WITNESS WHEREOF, the Borrowers, the Lenders and the Administrative Agent
          have
          executed this Agreement as of the date first above written.

         

        UNIT
          CORPORATION,
          a
          Delaware corporation,

        SUPERIOR
          PIPELINE COMPANY, L.L.C.,

        an
          Oklahoma limited liability company,

        UNIT
          PETROLEUM COMPANY,
          an
          Oklahoma

        corporation,

        UNIT
          DRILLING COMPANY,
          an
          Oklahoma

        corporation,
          and

        UNIT
          TEXAS DRILLING, L.L.C.,
          an
          Oklahoma

        limited
          liability company

         

        By     
          /s/ Larry D.
          Pinkston                 


               
          Larry D. Pinkston, as President of 

               
          UNIT CORPORATION, 

               
          UNIT PETROLEUM COMPANY, and

               
          UNIT DRILLING COMPANY, and

               
          as Chairman of SUPERIOR PIPELINE

               
          COMPANY, L.L.C, and

               
          as manager of UNIT TEXAS DRILLING,

               
          L.L.C.

         

        
                                                 
            7130 South Lewis Avenue, Suite 1000

        

                                               
          Tulsa, Oklahoma 74136

               
          Telephone: (918) 493-7700

               
          Facsimile (918) 493-7711

               
          Attention: Larry D. Pinkston

         

        


         


        
          
            
              
                	 	 	 


              

              


            

            
            

          

          
            
            

            
            

          

          
            
            

            
            

          

        



        BANK
          OF OKLAHOMA, NATIONAL

        ASSOCIATION,
          as LC
          Issuer, as Administrative

        Agent,
          and as a Lender 

         

        By     
          /s/ Pam
          Schloeder                  


               
          Pam Schloeder

               
          Senior Vice President


         

               
          101 East Second Street

               
          Bank of Oklahoma Tower -8th
          floor/Energy

               
          Department

               
          One Williams Center

               
          Tulsa, Oklahoma 74172

               
          Telephone: (918) 588-6012

               
          Facsimile: (918) 588-6880

         

        


         


        
          
            
              
                	 	 	 


              

              


            

            
            

          

          
            
            

            
            

          

          
            
            

            
            

          

        



        BANK
          OF AMERICA, N.A.,
          a
          Lender

         

        By      /s/
          Christen A.
          Lacey             

               
          Christen A. Lacey

               
          Principal

         

               
          100 Federal Street

               
          Boston, MA 02110

               
          Telephone: (617) 434-6816

               
          Facsimile: (617) 434-3652

         

        


         

        


         


        
          
            
              
                	 	 	 


              

              


            

            
            

          

          
            
            

            
            

          

          
            
            

            
            

          

        



        BMO
          CAPITAL MARKETS FINANCING, 

        INC.,
          a
          Lender

         

        By     
          /s/ Mary Lou
          Allen                    


               
          Mary Lou Allen,

               
          Vice President


         

               
          BMO Capital Markets Financing, Inc.

               
          Houston Agency

               
          700 Louisiana Street

               
          4400 Bank of America Center

               
          Houston, Texas 77002

               
          Telephone: (713) 546-9761

               
          Facsimile: (713) 223-4007

         

        


         


        
          
            
              
                	 	 	 


              

              


            

            
            

          

          
            
            

            
            

          

          
            
            

            
            

          

        



        COMPASS
          BANK,
          a
          Lender

         

        By     
          /s/ Kathleen J.
          Bowen                 
   

               
          Kathleen J. Bowen

               
          Senior Vice President


         

               
          24 Greenway Plaza

               
          Suite 1400A

               
          Houston, Texas 77046

               
          Telephone: (713) 968-8273

               
          Facsimile: (713) 968-8292

         

        



        
          
            
              
                	 	 	 


              

              


            

            
            

          

          
            
            

            
            

          

          
            
            

            
            

          

        



        FORTIS
          CAPITAL CORP., a
          Lender

         

        By    /s/
          Michele
          Jones                     

               
          Michele Jones

               
          Senior Vice President

         

        By     /s/
          Darrell
          Holley                  
   

               
          Darrell Holley

               
          Managing Director

         

        
                                                 
            15455 North Dallas Parkway

        

               
          Suite 1400

               
          Addison, Texas 75001

               
          Telephone: (214) 953-9308

               
          Facsimile: (214) 754-5982

         

        



        
          
            
              
                	 	 	 


              

              


            

            
            

          

          
            
            

            
            

          

          
            
            

            
            

          

        



        COMERICA
          BANK, a
          Lender

         

        By     /s/
          Juli
          Bieser                          
   

               
          Juli Bieser, 

               
          Senior Vice President


         

               
          910 Louisiana

               
          Suite 410 

               
          Houston, Texas 77002

               
          Telephone: (713) 220-5640

               
          Facsimile: (713) 220-5651

         

        



        
          
            
              
                	 	 	 


              

              


            

            
            

          

          
            
            

            
            

          

          
            
            

            
            

          

        



        STERLING
          BANK,
          a
          Lender

         

        By     
          /s/ Melissa
          Bauman                   
  

               
          Melissa Bauman, 

               
          Senior Vice President


         

               
          2550 N. Loop West

               
          Suite 800

               
          Houston, Texas 77092

               
          Telephone: (713) 507-7377

               
          Facsimile: (713) 507-7948

         

        



        
          
            
              
                	 	 	 


              

              


            

            
            

          

          
            
            

            
            

          

          
            
            

            
            

          

        



        CALYON
          NEW YORK BRANCH, a
          Lender

         

        By    
          /s/ Tom
          Byargeon                     
   

               
          Tom Byargeon

               
          Managing Director

         

        By     
          /s/ Michael
          Willis                     
  

               
          Michael Willis

               
          Director

         

         

               
          1301 Travis Street

               
          Suite 2100

               
          Houston, Texas 77002

               
          Telephone: (713) 890-8616

               
          Facsimile: (713) 890-8668

         

        
          
            
            

          

          
            
            

            
            

          

          
            
            

          

        

        
          EXHIBIT
            A

           

          FORM
            OF PROMISSORY NOTE

           

          (______________)

           

          $____________                                                       May
            24, 2007

                                                                        
            Tulsa, Oklahoma

           

          FOR
            VALUE RECEIVED, the undersigned, UNIT CORPORATION, a Delaware
            corporation, SUPERIOR PIPELINE COMPANY, L.L.C., an Oklahoma limited liability
            company, UNIT DRILLING COMPANY, an Oklahoma corporation, UNIT PETROLEUM
            COMPANY,
            an Oklahoma corporation, and UNIT TEXAS DRILLING, L.L.C., an Oklahoma
            limited
            liability company (individually and collectively the "Borrowers"), jointly
            and
            severally promise to pay to the order of ______________________ ("____"),
            with
            interest, the principal sum of ________________________ and NO/100ths
            DOLLARS
            ($____________) or, if less, the aggregate principal amount of all advances
            outstanding from time to time hereunder, made by ______ to Borrowers
            pursuant to
            the Credit Agreement (hereinafter defined) and unless otherwise provided
            in the
            Credit Agreement, the principal balance of this Note outstanding on the
            Facility
            Termination Date, with interest payments due on each applicable Payment
            Date.
            This Note is issued pursuant to and subject to the terms of a certain
            First
            Amended and Restated Senior Credit Agreement dated as of May 24, 2007,
            among
            Borrowers, the Lenders signatory parties thereto (collectively the "Lenders"),
            with Bank of Oklahoma, National Association, as the Administrative Agent
            for the
            Lenders (in such capacity, the "Administrative Agent") (such Credit Agreement,
            as hereafter amended, modified, supplemented or restated from time to
            time
            collectively referred to as the "Credit Agreement"). Capitalized terms
            used and
            not otherwise defined herein shall have the meanings assigned to them
            in the
            Credit Agreement.

           

          Except
            as hereinafter provided in connection with a Default,
            interest shall accrue on the outstanding principal balance hereof and
            on any
            past due interest to the Facility Termination Date at the rate or rates
            per
            annum determined pursuant to the Pricing Schedule annexed to the Credit
            Agreement, as provided in and calculated pursuant to the Credit Agreement.

           

          The
            rate of interest payable upon the indebtedness evidenced by
            this Note shall not at any time exceed the maximum rate of interest permitted
            under the laws of the State of Oklahoma or federal laws to the extent
            they apply
            to loans of the type and character evidenced by this Note.

           

          All
            payments under this Note shall be made in legal tender of the
            United States of America or in other immediately available funds at the
            offices
            of the Administrative Agent at Bank of Oklahoma Tower, One Williams Center,
            Seven East Second Street, Tulsa, Oklahoma 74172, and no credit shall
            be given
            for any payment received by check, draft or other instrument or item
            until such
            time as the Administrative Agent or the holder hereof shall have received
            credit
            therefor from the Administrative Agent's or the holder's collecting agent
            or, in
            the event no collecting agent is used, from the bank or other financial
            institution upon which said check, draft or other instrument or item
            is drawn.
            If any payment is due upon a Saturday or Sunday or upon any other day
            on which
            state or national banks in the 

           

          
            
              
              

              
              

            

            
              
              
State of Oklahoma are closed
              for business by virtue of a legal holiday for such banks, such payment
              shall be
              due and payable on the next succeeding Business Day, and interest shall
              accrue
              to such day.

          

           

          The
            Borrowers may borrow and reborrow hereunder at any time and
            from time to time as provided in the Credit Agreement and may prepay
            this Note
            in whole or in part, subject to the prepayment limitations contained
            in the
            Credit Agreement; provided, however, that any partial prepayment shall
            be
            applied first to accrued interest, then to the unpaid principal balance
            hereof.

           

          From
            time to time the Borrowers and the Lenders may agree to
            extend the maturity date of this Note or to renew this Note, in whole
            or in
            part, or a new note of different form may be substituted for this Note
            and/or
            the rate of interest may be changed, or changes may be made in consideration
            of
            loan extensions, and the holder, from time to time, may waive or surrender,
            either in whole or in part, any rights, guarantees, security interests,
            or liens
            given for the benefit of the holder in connection with the payment and
            the
            securing the payment of this Note; but no such occurrences shall in any
            manner
            affect, limit, modify or otherwise impair any rights, guarantees or security
            of
            the holder not specifically waived, released or surrendered in writing,
            nor
            shall the Borrowers or any guarantor, endorser or any other person who
            is or
            might be liable hereon, either primarily or contingently, be released
            from such
            liability by reason of the occurrence of any such event. The holder hereof,
            from
            time to time, shall have the unlimited right to release any person who
            might be
            liable hereon; and such release shall not affect or discharge the liability
            of
            any other person who is or might be liable hereon.

           

          This
            Note is subject to and governed by the terms, provisions,
            conditions and limitations of the Credit Agreement concerning, among
            other
            matters, acceleration following a Default, imposition of default rates
            of
            interest during the continuance of a Default, methods of payment, minimum
            amounts of each Advance, selection of the type of Advance and applicable
            Interest Period for new Advances, Borrowing Base calculations, Maximum
            Credit
            Amount, Aggregate Commitment amounts, a negative pledge of certain assets
            of the
            Borrowers, rights of set off or offset in connection therewith and all
            other
            matters terms, provisions and agreements therein prescribed or governed.


           

          The
            Borrowers and all endorsers, guarantors and sureties hereby
            severally waive protest, presentment, demand, and notice of protest and
            nonpayment in case this Note or any payment due hereunder is not paid
            when due;
            and they agree to any renewal of this Note or to any extension, acceleration
            or
            postponement of the time of payment, or any other indulgence, to any
            substituting, exchange or release of collateral and to the release of
            any party
            or person primarily or contingently liable hereon without prejudice to
            the
            holder and without notice to the Borrowers or any endorser, guarantor
            or surety.
            In the event of any controversy, claim or dispute among the parties affecting
            or
            relating to the subject matter or performance of this Note, the prevailing
            party
            shall be entitled to recover from the non-prevailing party all of its
            reasonable
            costs, expenses, including reasonable attorneys' and accountants' fees.
            In the
            event the Administrative Agent or _________ is the prevailing party,
            the
            Borrowers, and any guarantor, endorser, surety or any other person who
            is or may
            become liable hereon, will, on demand, pay all such costs and expenses.

           

          
            
            

            
            

          

          
            
            

          

          [This
            Note is a replacement of that certain promissory note dated
            as of January 25, 2007, issued under the Existing Credit Agreement and
            payable
            by the Borrowers to the order of ____ in the original principal amount
            of
            $__________.] 

           

          This
            Note is issued by the Borrowers in accordance with the
            provisions of Section 2.14(iv) of the Credit Agreement and shall be governed
            by
            and construed in accordance with the laws of the State of Oklahoma. Borrowers
            agree that all suits or proceedings arising from or related to this Note
            or the
            Credit Agreement may be litigated in courts, state or federal, sitting
            in Tulsa
            County, State of Oklahoma. In furtherance of this provision, Borrowers
            hereby
            waive any objection to such venue.

           

          Notwithstanding
            the single execution of this Note by the
            undersigned President of each of the corporate Borrowers and the manager
            of the
            limited liability companies Borrower, as applicable, each of the Borrowers
            is
            jointly and severally bound by the terms of this Note.

           

          UNIT
            CORPORATION, a Delaware corporation,

          SUPERIOR
            PIPELINE COMPANY, L.L.C.,

          an
            Oklahoma limited liability company,

          UNIT
            PETROLEUM COMPANY, an Oklahoma

          corporation,

          UNIT
            DRILLING COMPANY, an Oklahoma

          corporation,
            and

          UNIT
            TEXAS DRILLING, L.L.C., an Oklahoma

          limited
            liability company

           

          By_____________________________________

           

          Larry
            D. Pinkston, President of each of

          UNIT
            CORPORATION,

          UNIT
            PETROLEUM COMPANY,

          UNIT
            DRILLING COMPANY, and

          as
            Manager of UNIT TEXAS DRILLING,

          L.L.C.,
            and Chairman of SUPERIOR

          PIPELINE
            COMPANY, L.L.C.

           

          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          

          EXHIBIT
            B

          COMPLIANCE
            CERTIFICATE

           

          Bank
            of Oklahoma, National Association, as

          Administrative
            Agent

          Bank
            of Oklahoma Tower - 8th Floor/Energy Dept.

          One
            Williams Center

          Tulsa,
            Oklahoma 74192

          


          This
            Compliance Certificate is delivered pursuant to Section
            6.1(iii) of that certain First Amended and Restated Senior Credit Agreement,
            dated as of May 24, 2007 (as amended, modified, supplemented or restated
            from
            time to time, the "Credit Agreement"), by and among Unit Corporation,
            a Delaware
            corporation ("Unit") ("Unit" and the subsidiaries thereof signatory parties
            to
            the Credit Agreement, as borrowers, collectively the "Borrowers"), the
            Lenders
            (as therein defined), and Bank of Oklahoma, National Association, as
            Administrative Agent for the Lenders. Capitalized terms used herein and
            not
            otherwise defined have the respective meanings assigned to them in the
            Credit
            Agreement. 

           

          As
            used in this Compliance Certificate (including the Schedules
            attached hereto), "Quarterly Calculation Date" means the last day of
            the fiscal
            quarter ending ___________, 200_.

           

          The
            undersigned hereby certifies, represents and warrants as
            follows:

           

          1. The
            undersigned is the chief financial officer of Unit and
            as such he or she is authorized to execute and deliver this Compliance
            Certificate on behalf of the Borrowers and their Subsidiaries (collectively,
            the
            "Credit Parties").

           

          2. The
            undersigned has reviewed the activities of the Credit
            Parties with a view to determining whether the Credit Parties have fulfilled
            their respective obligations under the Loan Documents.

           

          3. Except
            as set forth on Schedule I attached hereto, to the
            best knowledge of the undersigned, after due inquiry:

           

          (a)
 each
            of the Credit Parties has complied with and is in
            compliance with all of the terms and provisions of each of the Loan Documents
            to
            which it is a party;

           

          (b)
 all
            representations and warranties made by the Borrowers
            in the Credit Agreement are true and correct in all material respects
            as of the
            date hereof (other than representations and warranties which refer solely
            to an
            earlier specified date); and

           

          (c) no
            Default has occurred and is continuing under the
            Credit Agreement.

           

          4. As
            of the Quarterly Calculation Date, the Borrowers were
            in compliance with the financial covenants set forth in Sections 8.1,
            8.2 and
            8.3 of the Credit Agreement, as demonstrated by the computations set
            forth in
            Schedule II attached hereto, calculated in accordance with GAAP to the
            extent
            applicable.

           

          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          

          5. Schedule
            III attached hereto contains a complete and
            accurate list of all Material Subsidiaries of the Borrowers. The Borrowers
            have
            complied with Section 9.2 of the Credit Agreement by causing each of
            the
            Material Subsidiaries to become a party to the Subsidiary Guaranty.

           

          IN
            WITNESS WHEREOF, I have executed this Certificate this ______
            day of ___________, 200_.

           

           

                                     _______________________________________

                                     ________________________(name)

            
Chief
            Financial Officer

            
Unit
            Corporation

           

           

          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          

          



          SCHEDULE
            I

          TO
            COMPLIANCE CERTIFICATE

           

          (Disclosure
            of Defaults and Non-Compliance)

          


           

          A. Nature
            of Default or terms of Loan Documents that have not
            been complied with in all material respects:

           

          


           

          


           

          


           

          B. Steps
            being taken to correct such Default or
            noncompliance:

           

          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          

          SCHEDULE
            II

          TO
            COMPLIANCE CERTIFICATE

           

          (Financial
            Covenant Calculations)

          


          1. Calculation
            of Current Ratio
            (Section 8.1)

          (To
            be calculated on a consolidated basis for Unit as of the
            Quarterly Calculation Date)

          


          
            	
                           
Current
                      Assets
                      (including Available

                  	
                    $_______________________

                  
	
                           
Aggregate
                      Commitment)

                  	 
	
                           
Divided
                      by:
                      Current Liabilities

                  	
                    ÷_______________________

                  
	
                           


                           
Consolidated
                      Current
                      Ratio:

                  	
                     

                    =_______________________

                    (must
                      be equal to or greater

                    than
                      1.0 to 1.0)

                  


          

           

          2. Consolidated
            Long Term
            Debt-to-EBITDA Ratio (Section 8.2)

          (To
            be calculated on a consolidated basis for Unit as of the
            Quarterly Calculation Date)

          


          
            	
                           
A. Consolidated
                      Long Term Debt

                  	
                    $______________________

                  
	 	 
	
                           
B. Consolidated
                      EBITDA

                  	
                    $______________________

                  
	 	 
	
                           
C. Consolidated
                      Long Term Debt to 

                                
                      EBITDA Ratio (Ratio of Item A to 

                                
                      Item B)

                  	
                    ____________
                      to 1.00

                    (must
                      not be greater than 3.50 to
                      1.00)

                  


          

          


          3. Calculation
            of Consolidated Minimum
            Net Worth (Section 8.3)

          (To
            be calculated for Unit as of the Quarterly Calculation
            Date)

          


          
            	
                           
Consolidated
                      Net
                      Worth

                  	
                    $______________________

                    (must
                      be equal to or greater 

                    than
                      $900,000,000)

                  


          

          


          


          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          

           


          SCHEDULE
            III

           

          TO
            COMPLIANCE CERTIFICATE

           

          (Material
            Subsidiaries)

          


          As
            of the Quarterly Calculation Date, the following constituted
            all of the Material Subsidiaries of the Borrowers:

           

          


          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          


          EXHIBIT
            C

          FORM
            OF ASSIGNMENT

           

          This
            Assignment and Assumption (the "Assignment and Assumption")
            is dated as of the Effective Date set forth below and is entered into
            by and
            between [Insert name of Assignor] (the "Assignor") and [Insert name
            of Assignee] (the "Assignee"). Capitalized terms used but not defined
            herein shall have the meanings given to them in the First Amended and
            Restated
            Senior Credit Agreement dated as of May 24, 2007 (as amended, restated
            or
            supplemented from time to time, the "Credit Agreement"), receipt of a
            copy of
            which is hereby acknowledged by the Assignee. The Terms and Conditions
            set forth
            in Annex 1 attached hereto are hereby agreed to and incorporated herein
            by
            reference and made a part of this Assignment and Assumption as if set
            forth
            herein in full.

           

          The
            Assignor hereby sells and assigns to the Assignee, and the
            Assignee hereby purchases and assumes from the Assignor, an interest
            in and to
            the Assignor's rights and obligations under the Credit Agreement and
            the other
            Loan Documents, such that after giving effect to such assignment the
            Assignee
            shall have purchased pursuant to this Assignment Agreement the percentage
            interest specified in Item 6(a) below of all outstanding rights and obligations
            under the Credit Agreement and the other Loan Documents relating to the
            credit
            facility listed in Item 5 below (the "Assigned Interest"). The aggregate
            Commitment (including LC Obligations, if the applicable Commitment has
            been
            terminated) purchased by the Assignee hereunder is set forth in Item
            6
            below.

           

          In
            consideration for the sale and assignment of Commitments
            hereunder, the Assignee shall pay the Assignor, on the Effective Date,
            the
            amount agreed to by the Assignor and the Assignee. On and after the Effective
            Date, the Assignee shall be entitled to receive all payments of principal,
            interest, reimbursement obligations and fees with respect to the interest
            assigned hereby. The Assignee will promptly remit to the Assignor any
            interest
            on Loans and fees received from the Administrative Agent which relate
            to the
            portion of the Loans or LC Obligations assigned to the Assignee hereunder
            and
            not previously paid by the Assignee to the Assignor. In the event that
            either
            party hereto receives any payment to which the other party hereto is
            entitled
            under this Assignment Agreement, then the party receiving such amount
            shall
            promptly remit it to the other party hereto. 

           

          1. Assignor: __________________________

           

          2. Assignee: __________________________
            [and is an
            Affiliate of ___________________________[identify
            Lender]1  

           

          3. Borrowers: Unit
            Corporation, Superior Pipeline
            Company, L.L.C., Unit Drilling Company, Unit Petroleum Company, and Unit
            Texas
            Drilling, L.L.C.

           

          4. Administrative
            Agent:  Bank of Oklahoma, National
            Association, as Administrative Agent under the Credit Agreement.

           

          _____________________

          1.
            Select as applicable

           

          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          

          5. Credit
            Agreement: The $400,000,000 First Amended and
            Restated Senior Credit Agreement dated as of May 24 , 2007 among Borrowers,
            Bank
            of Oklahoma, National Association, as Administrative Agent, and the Lenders
            signatory parties thereto.

           

          6. Assigned
            Interest: ____________________

           

          
            	
                                   
                      a. Assignee's Pro Rata Share of credit facility 

                         purchased
                      under the Assignment Agreement

                  	
                    __________%

                  
	
                                   
                      b. Amount of credit facility purchased under the

                        
Assignment
                      Agreement

                  	
                    $___________

                  
	
                                   
                      c. Assignee's Loans (or LC Obligations with respect to 

                        
terminated
                      Commitments) purchased hereunder:

                  	
                    $___________

                  


          

           

          7. Trade
            Date: _________________________________
2 

           

          8. Payment
            Instructions to Assignor:

           

          Effective
            Date: ________________, 200__ [TO BE INSERTED BY
            ADMINISTRATIVE AGENT AND WHICH SHALL BE THE EFFECTIVE DATE OF RECORDATION
            OF
            TRANSFER BY THE ADMINISTRATIVE AGENT.]

           

           

           

           

           

          ______________________

          2.
            Insert if satisfaction of minimum amounts is to be determined
            as of the Trade Date.


          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          


          The
            terms set forth in this Assignment and Assumption are hereby
            agreed to:

           

          ASSIGNOR

           

          [name]

           

          BY:________________________________

          Title:_______________________________

           

          


           

          ASSIGNEE

           

          [name]

           

          BY:________________________________

          Title:_______________________________

           

          


           

          Consented
            and Accepted:

           

          BANK
            OF OKLAHOMA, National Association,

          as
            Administrative Agent for the Lenders

           

          By:_____________________________

          Name:
            __________________________

          Title:
            ___________________________

           

          


           

          


           

          UNIT
            CORPORATION

           

          


           

          By:______________________________

          Name:
            ___________________________

          Title:
            ____________________________

           

          


          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          

           

          ANNEX
            1

          TERMS
            AND CONDITIONS FOR

          ASSIGNMENT
            AND ASSUMPTION

           

          1. Representations
            and Warranties.

           

          1.1 Assignor.
            The Assignor represents and warrants
            that (i) it is the legal and beneficial owner of the Assigned Interest,
            (ii) the
            Assigned Interest is free and clear of any lien, encumbrance or other
            adverse
            claim and (iii) it has full power and authority, and has taken all action
            necessary, to execute and deliver this Assignment and Assumption and
            to
            consummate the transactions contemplated hereby. Neither the Assignor
            nor any of
            its officers, directors, employees, agents or attorneys shall be responsible
            for
            (i) any statements, warranties or representations made in or in connection
            with
            the Credit Agreement or any other Loan Document, (ii) the execution,
            legality,
            validity, enforceability, genuineness, sufficiency, perfection, priority,
            collectibility, or value of the Loan Documents or any collateral thereunder,
            (iii) the financial condition of the Borrowers, any of their Subsidiaries
            or
            Affiliates or any other Person obligated in respect of any Loan Document,
            (iv)
            the performance or observance by the Borrowers, any of their Subsidiaries
            or
            Affiliates or any other Person of any of their respective obligations
            under any
            Loan Document, (v) inspecting any of the property, books or records of
            the
            Borrowers, or Subsidiary Guarantor, or (vi) any mistake, error of judgment,
            or
            action taken or omitted to be taken in connection with the Loans or the
            Loan
            Documents.

           

          1.2 Assignee.
            The Assignee (a) represents and warrants
            that (i) it has full power and authority, and has taken all action necessary,
            to
            execute and deliver this Assignment and Assumption and to consummate
            the
            transactions contemplated hereby and to become a Lender under the Credit
            Agreement, (ii) from and after the Effective Date, it shall be bound
            by the
            provisions of the Credit Agreement as a Lender thereunder and, to the
            extent of
            the Assigned Interest, shall have the obligations of a Lender thereunder,
            (iii)
            agrees that its payment instructions and notice instructions are as set
            forth in
            Item 8 above of this Assignment and Assumption, (iv) confirms that none
            of the
            funds, monies, assets or other consideration being used to make the purchase
            and
            assumption hereunder are "plan assets" as defined under ERISA and that
            its
            rights, benefits and interests in and under the Loan Documents will not
            be "plan
            assets" under ERISA, (v) agrees to indemnify and hold the Assignor harmless
            against all losses, costs and expenses (including, without limitation,
            reasonable attorneys' fees) and liabilities incurred by the Assignor
            in
            connection with or arising in any manner from the Assignee's non- performance
            of
            the obligations assumed under this Assignment and Assumption, (vi) it
            has
            received a copy of the Credit Agreement, together with copies of financial
            statements and such other documents and information as it has deemed
            appropriate
            to make its own credit analysis and decision to enter into this Assignment
            and
            Assumption and to purchase the Assigned Interest on the basis of which
            it has
            made such analysis and decision independently and without reliance on
            the
            Administrative Agent or any other Lender, and (vii) attached as Schedule
            1 to
            this Assignment and Assumption is any documentation required to be delivered
            by
            the Assignee with respect to its tax status pursuant to the terms of
            the Credit
            Agreement, exemption from backup withholding (IRS From W-9 or successor
            form) on
            payments pursuant to the Credit 

           

          
            
              
              

            

            
              
              

              
              

            

            
              
              
Agreement or and other Loan Document described or defined
              therein or as a Lender that is not a United States person under Section
              7701(a)(30) of the Internal Revenue Code for United States federal
              income tax
              purposes, duly completed and executed by the Assignee and (b) agrees
              that (i) it
              will, independently and without reliance on the Administrative Agent,
              the
              Assignor or any other Lender, and based on such documents and information
              as it
              shall deem appropriate at the time, continue to make its own credit
              decisions in
              taking or not taking action under the Loan Documents, and (ii) it will
              perform
              in accordance with their terms all of the obligations which by the
              terms of the
              Loan Documents are required to be performed by it as a Lender.

          

           

          2.
 Payments.
            The Assignee shall pay the Assignor, on
            the Effective Date, the amount agreed to by the Assignor and the Assignee.
            From
            and after the Effective Date, the Administrative Agent shall make all
            payments
            in respect of the Assigned Interest (including payments of principal,
            interest,
            fees and other amounts) to the Assignor for amounts which have accrued
            to but
            excluding the Effective Date and to the Assignee for amounts which have
            accrued
            from and after the Effective Date. 

           

          3.
 General
            Provisions. This Assignment and Assumption
            shall be binding upon, and inure to the benefit of, the parties hereto
            and their
            respective successors and assigns. This Assignment and Assumption may
            be
            executed in any number of counterparts, which together shall constitute
            one
            instrument. Delivery of an executed counterpart of a signature page of
            this
            Assignment and Assumption by telecopy shall be effective as delivery
            of a
            manually executed counterpart of this Assignment and Assumption. This
            Assignment
            and Assumption shall be governed by, and construed in accordance with,
            the laws
            of the State of Oklahoma.

           

          


          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          


          SCHEDULE
            I

           

          (Lender
            Tax Status Information)

          


          


          


          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          

          



          EXHIBIT
            D

           

          FORM
            OF AMENDMENT FOR AN INCREASED OR NEW
            COMMITMENT

           

          This
            AMENDMENT is made as of the ___ day of __________, 200__, by
            and among Unit Corporation, a Delaware corporation (as agent for the
            "Borrowers"
            signatory parties to the Credit Agreement described and defined below,
            referred
            to herein as "Unit"), Bank of Oklahoma, National Association, as administrative
            agent for the Lenders signatory parties to the Credit Agreement (the
            "Administrative Agent"), and _________________________ (the "Supplemental
            Lender").

           

          The
            Borrowers (including Unit), the Administrative Agent and
            certain other Lenders, as described therein, are parties to a First Amended
            and
            Restated Senior Credit Agreement dated as of May 24, 2007 (as amended,
            modified,
            supplemented, or restated, collectively the "Credit Agreement"). All
            terms used
            herein and not otherwise defined shall have the same meaning given to
            them in
            the Credit Agreement. 

           

          Pursuant
            to Section 14.6 of the Credit Agreement, Unit, on behalf
            of the Borrowers, has the right to obtain additional Commitments upon
            satisfaction of certain conditions. This Amendment requires only the
            signature
            of Unit, the Administrative Agent and the Supplemental Lender so long
            as the
            aggregate amount of the commitments is not increased above the Maximum
            Credit
            Amount specified in the Credit Agreement.

           

          The
            Supplemental Lender is either (a) an existing Lender which is
            increasing its Commitment or (b) a new Lender which is a lending institution
            whose identity the Administrative Agent will approve by its signature
            below.


           

          In
            consideration of the foregoing, such Supplemental Lender, from
            and after the date hereof shall have a Commitment of $_______________
            and if it
            is a new Lender, the Supplemental Lender hereby assumes all of the rights
            and
            obligations of a Lender under the Credit Agreement.

           

          The
            Borrowers have executed and delivered to the Supplemental
            Lender as of the date hereof, if requested by the Supplemental Lender,
            a new or
            amended and restated Note in the form attached to the Credit Agreement
            as
            Exhibit A to evidence the new or increased Commitment of the Supplemental
            Lender
            and the Administrative Agent is distribution a revised Lenders Schedule
            to the
            Lenders in the form annexed hereto.

           

          IN
            WITNESS WHEREOF, the Administrative Agent, the Borrower and the
            Supplemental Lender have executed this Amendment as of the date shown
            above.

           

          UNIT
            CORPORATION

           

          By:_____________________________________

                     
            __________________________(name)

                     
            __________________________(title)

           

          


          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          

           

          [SUPPLEMENT
            LENDER]

           

          By:_____________________________________

          Name:
            __________________________________

          Title:
            _______________________________

           

          


           

          BANK
            OF OKLAHOMA, NATIONAL ASSOCIATION, Administrative Agent for the
            Lenders

           

          


           

          By:_____________________________________

          Name:
            __________________________________

          Title:
            _______________________________

           

          


          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          


          EXHIBIT
            E

           

          SUBSIDIARY GUARANTY

           

          THIS
            GUARANTY AGREEMENT ("Guaranty") is made and entered into
            effective as of ________, 20___, by the undersigned guarantor (the "Guarantor"),
            in favor of (i) the Lenders from time to time parties to the Credit Agreement
            described below and (ii) Bank of Oklahoma, National Association, as
            Administrative Agent under the Credit Agreement (defined below).

           

          RECITALS

           

          A. Unit
            Corporation, a Delaware corporation, Superior
            Pipeline Company, L.L.C., an Oklahoma limited liability company, Unit
            Drilling
            Company, an Oklahoma corporation, Unit Petroleum Company, Inc., an Oklahoma
            corporation, and Unit Texas Drilling, L.L.C., an Oklahoma limited liability
            company (collectively, the "Borrowers"), the Lenders therein named, and
            Bank of
            Oklahoma, National Association, as Administrative Agent for the Lenders,
            are
            parties to that certain First Amended and Restated Senior Credit Agreement
            dated
            as of May 24, 2007 (as amended, modified, supplemented, restated and
            in effect
            from time to time, the "Credit Agreement"). 

           

          B. Capitalized
            terms used herein and not otherwise defined
            herein have the respective meanings assigned to them in the Credit
            Agreement.

           

          C. Pursuant
            to the Credit Agreement, the Lenders have
            severally agreed to establish in favor of the Borrowers certain Commitments
            for
            Advances and LC Obligations in the Aggregate Commitment Amounts, subject
            to the
            Maximum Credit Amount.

           

          D. The
            Guarantor is a Material Subsidiary and will receive
            substantial and valuable consideration and benefit from the Commitments
            and the
            Loans advanced and the LCs issued from time to time by the Lenders and
            the LC
            Issuer, respectively, to the Borrowers pursuant to the Credit Agreement.

           

          D. It
            is a condition precedent to the closing of the Credit
            Agreement and to each Extension of Credit thereunder that the Guarantor
            executes
            and delivers this Guaranty whereby the Guarantor shall absolutely and
            unconditionally guarantee the prompt and punctual payment when due of
            all of the
            Guaranteed Obligations (as hereinafter defined).

           

          NOW,
            THEREFORE, in consideration of the credit to be extended
            pursuant to the Credit Agreement, and as a material inducement therefor,
            and for
            other good and valuable consideration, the receipt and sufficiency of
            which are
            hereby acknowledged, the Guarantor hereby covenants and agrees as follows:

           

          SECTION
            1. Guaranty. Subject to Section 9 hereof, the
            Guarantor hereby guarantees to the Lenders and the Administrative Agent,
            absolutely, unconditionally and irrevocably, and without limitation as
            to
            amount, the prompt performance and payment when due (whether at a stated
            maturity or earlier by reason of acceleration or otherwise) of all Loans,
            LC
            Obligations, Reimbursement Obligations and all other Obligations and
            Outstanding
            Credit Exposure (as each such term is defined in the Credit Agreement),
            including, without limitation, principal, interest and fees, and all
            other


           

           

          
            
              
              

            

            
              
              

              
              

            

            
              
              
liabilities and obligations
              now or hereafter owing by the Borrowers to the Lenders under the Credit
              Agreement, the Notes and other relevant Loan Documents, including,
              without
              limitation, indemnities, reasonable attorneys' fees, filing and recording
              costs,
              out-of-pocket expenses, collection costs and other amounts payable
              under the
              Loan Documents, including any such liabilities or obligations incurred
              or
              accrued during the pendency of any bankruptcy, insolvency, receivership
              or other
              similar proceeding, whether or not allowed or allowable in such proceeding
              (all
              of the foregoing liabilities and obligations being hereinafter collectively
              referred to as the "Guaranteed Obligations"). This Guaranty is a guaranty
              of
              payment and not just of collectibility and is in no way conditioned
              or
              contingent upon any attempt to collect from the Borrowers or upon any
              other
              event, contingency or circumstance whatsoever. If for any reason whatsoever
              the
              Borrowers shall fail or be unable duly, punctually and fully to pay
              such amounts
              as and when the same shall become due and payable, the Guarantor, without
              demand, presentment, protest or notice of any kind, will forthwith
              pay or cause
              to be paid such amounts to the Administrative Agent under the terms
              of the
              Credit Agreement, any Note or other relevant Loan Document, in lawful
              money of
              the United States, at the place specified in the Credit Agreement,
              or perform or
              comply with the same or cause the same to be performed or complied
              with,
              together with interest (to the extent provided for under the Credit
              Agreement)
              on any amount due and owing from the Borrowers. The Guarantor, promptly
              after
              demand, will pay to the Administrative Agent the reasonable costs and
              expenses
              of collecting such amounts or otherwise enforcing this Guaranty, including,
              without limitation, the reasonable fees and expenses of counsel. Notwithstanding
              the foregoing, the right of recovery against the Guarantor under this
              Guaranty
              is limited to the extent it is judicially determined with respect to
              any
              Guarantor that entering into this Guaranty would violate Section 548
              of the
              United States Bankruptcy Code or any comparable provisions of any state
              law, in
              which case such Guarantor shall be liable under this Guaranty only
              for amounts
              aggregating up to the largest amount that would not render such Guarantor's
              obligations hereunder subject to avoidance under Section 548 of the
              United
              States Bankruptcy Code or any comparable provisions of any state
              law.

          

           

          SECTION
            2. Guarantor's Obligations Unconditional. The
            obligations of the Guarantor under this Guaranty shall be primary, absolute
            and
            unconditional obligations of the Guarantor, shall not be subject to any
            counterclaim, set-off, deduction, diminution, abatement, recoupment,
            suspension,
            deferment, reduction or defense based upon any claim the Guarantor or
            any other
            Person may have against the Borrowers or any other Person, and to the
            full
            extent permitted by applicable law shall remain in full force and effect
            without
            regard to, and shall not be released, discharged or in any way affected
            by, any
            circumstance or condition whatsoever (whether or not the Guarantor or
            the
            Borrowers shall have any knowledge or notice thereof), including:

           

          (a) any
            termination, amendment or modification of or deletion
            from or addition or supplement to or other change in the Credit Agreement,
            the
            Loan Documents or any other instrument or agreement applicable to any
            of the
            parties to any of the Loan Documents;

           

          (b) any
            furnishing or acceptance of any security, or any
            release of any security, for the Guaranteed Obligations, or the failure
            of any
            security or the failure of any Person to perfect any interest in any
            collateral;

           

          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          

          (c) any
            failure, omission or delay on the part of the
            Borrowers to conform or comply with any term of any of the Loan Documents
            or any
            other instrument or agreement referred to in subsection (a) above, including,
            without limitation, failure to give notice to the Guarantor of the occurrence
            of
            a "Default" or an "Event of Default" under any Loan Document;

           

          (d) any
            waiver of the payment, performance or observance of
            any of the obligations, conditions, covenants or agreements contained
            in any
            Loan Document, or any other waiver, consent, extension, indulgence, compromise,
            settlement, release or other action or inaction under or in respect of
            any of
            the Loan Documents or any other instrument or agreement referred to in
            subsection (a) above or any obligation or liability of the Borrowers,
            or any
            exercise or non-exercise of any right, remedy, power or privilege under
            or in
            respect of any such instrument or agreement or any such obligation or
            liability;

           

          (e) any
            failure, omission or delay on the part of any of the
            Administrative Agent or the Lenders to enforce, assert or exercise any
            right,
            power or remedy conferred on the Administrative Agent or the Lenders
            in this
            Guaranty, or any such failure, omission or delay on the part of the
            Administrative Agent or the Lenders in connection with any Loan Document,
            or any
            other action on the part of the Administrative Agent or the Lenders;

           

          (f) any
            voluntary or involuntary bankruptcy, insolvency,
            reorganization, arrangement, readjustment, assignment for the benefit
            of
            creditors, composition, receivership, conservatorship, custodianship,
            liquidation, marshaling of assets and liabilities or similar proceedings
            with
            respect to the Borrowers, any Guarantor or any other Person or any of
            their
            respective properties or creditors, or any action taken by any trustee
            or
            receiver or by any court in any such proceeding;

           

          (g) any
            discharge, termination, cancellation, frustration,
            irregularity, invalidity or unenforceability, in whole or in part, of
            any of the
            Loan Documents or any other agreement or instrument referred to in subsection
            (a) above or any term hereof;

           

          (h) any
            merger or consolidation of the Borrowers or any
            Guarantor into or with any other corporation, or any sale, lease or transfer
            of
            any of the assets of the Borrowers or any Guarantor to any other Person;

           

          (i) any
            change in the ownership of any shares of capital
            stock of the Borrowers or any change in the corporate relationship between
            the
            Borrowers and the Guarantor, or any termination of such relationship;

           

          (j) any
            release or discharge, by operation of law, of the
            Guarantor from the performance or observance of any obligation, covenant
            or
            agreement contained in this Guaranty; or

           

          (k) any
            other occurrence, circumstance, happening or event
            whatsoever, whether similar or dissimilar to the foregoing, whether foreseen
            or
            unforeseen, and any other circumstance which might otherwise 

           

          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

            constitute
              a
              legal or equitable defense or discharge of the liabilities of a guarantor
              or
              surety or which might otherwise limit recourse against the
              Guarantor.

          

           

          SECTION
            3. Full Recourse Obligations. The obligations of
            the Guarantor set forth herein constitute the full recourse obligations
            of the
            Guarantor enforceable against them to the full extent of all their assets
            and
            properties.

           

          SECTION
            4. Waiver. The Guarantor unconditionally waives, to
            the extent permitted by applicable law, (a) notice of any of the matters
            referred to in Section 2 hereof, (b) notice to the Guarantor of the incurrence
            of any of the Guaranteed Obligations, notice to the Guarantor or the
            Borrowers
            of any breach or default by the Borrowers or the Guarantor with respect
            to any
            of the Guaranteed Obligations or any other notice that may be required,
            by
            statute, rule of law or otherwise, to preserve any rights of the Administrative
            Agent or the Lenders against the Guarantor, (c) presentment to or demand
            of
            payment from the Borrowers or the Guarantors with respect to any amount
            due
            under any Loan Document or protest for nonpayment or dishonor, (d) any
            right to
            the enforcement, assertion or exercise by the Administrative Agent or
            the
            Lenders of any right, power, privilege or remedy conferred in the Credit
            Agreement or any other Loan Document or otherwise, (e) any requirement
            of
            diligence on the part of any of the Administrative Agent or the Lenders,
            (f) any
            requirement to exhaust any remedies or to mitigate the damages resulting
            from
            any default under any Loan Document, (g) any notice of any sale, transfer
            or
            other disposition by any of the Lenders of any right, title to or interest
            in
            the Credit Agreement or in any other Loan Document, and (h) any other
            circumstance whatsoever which might otherwise constitute a legal or equitable
            discharge, release or defense of a guarantor or surety or which might
            otherwise
            limit recourse against the Guarantor.

           

          SECTION
            5. Subrogation, Contribution, Reimbursement or
            Indemnity. Until one year and one day after all Guaranteed Obligations have
            been indefeasibly paid in full, the Guarantor agrees not to take any
            action
            pursuant to any rights which may have arisen in connection with this
            Guaranty to
            be subrogated to any of the rights (whether contractual, under the United
            States
            Bankruptcy Code, as amended, including Section 509 thereof, under common
            law or
            otherwise) of any of the Lenders against the Borrowers or against any
            collateral
            security or guaranty or right of offset held by the Administrative Agent
            or the
            Lenders for the payment of the Guaranteed Obligations. Until one year
            and one
            day after all Guaranteed Obligations have been indefeasibly paid in full,
            the
            Guarantor agrees not to take any action pursuant to any contractual,
            common law,
            statutory or other rights of reimbursement, contribution, exoneration
            or
            indemnity (or any similar right) from or against the Borrowers which
            may have
            arisen in connection with this Guaranty. So long as the Guaranteed Obligations
            remain, if any amount shall be paid by or on behalf of the Borrowers
            to any
            Guarantor on account of any of the rights waived in this Section 5, such
            amount
            shall be held by such Guarantor in trust, segregated from other funds
            of such
            Guarantor, and shall, forthwith upon receipt by such Guarantor, be turned
            over
            to the Administrative Agent (duly endorsed by such Guarantor to the
            Administrative Agent, if required), to be applied against the Guaranteed
            Obligations, whether matured or unmatured, in such order as the Administrative
            Agent may determine. The provisions of this Section 5 shall survive the
            term of
            this Guaranty and the payment in full of the Guaranteed Obligations.

           

          SECTION
            6. Effect of Bankruptcy or Insolvency Proceedings.
            This Guaranty shall continue to be effective or be automatically reinstated,
            as
            the case may be, if at any time payment, in whole or in part, of any
            of the sums
            due to any 

           

          
            
              
              

            

            
              
              

              
              

            

            
              
              
of the Lenders pursuant to
              the terms of the Credit Agreement or any other Loan Document is rescinded
              or
              must otherwise be restored or returned by such Bank upon the insolvency,
              bankruptcy, dissolution, liquidation or reorganization of the Borrowers
              or any
              other Person, or upon or as a result of the appointment of a custodian,
              receiver, trustee or other officer with similar powers with respect
              to the
              Borrowers or other Person or any substantial part of its property,
              or otherwise,
              all as though such payment had not been made. If an event permitting
              the
              acceleration of the maturity of the principal amount of the Notes shall
              at any
              time have occurred and be continuing, and such acceleration shall at
              such time
              be prevented by reason of the pendency against the Borrowers or any
              other Person
              of a case or proceeding under a bankruptcy or insolvency law, the Guarantor
              agrees that, for purposes of this Guaranty and its obligations hereunder,
              the
              maturity of the principal amount of the Notes and all other Guaranteed
              Obligations shall be deemed to have been accelerated with the same
              effect as if
              the Lenders had accelerated the same in accordance with the terms of
              the Credit
              Agreement or other applicable Loan Document, and the Guarantor shall
              forthwith
              pay such principal amount and interest thereon and any other amounts
              guaranteed
              hereunder without further notice or demand.

          

           

          SECTION
            7. Termination. This Guaranty shall terminate when,
            and only when, all of the Guaranteed Obligations have been paid and performed
            in
            full, all in accordance with the provisions of the Credit Agreement.

           

          SECTION
            8.  Representations and Warranties. Guarantor
            represents and warrants that:

           

          (a) It
            (i) is duly organized, validly existing in good
            standing under the laws of the jurisdiction of its incorporation or
            organization, (ii) has the corporate or other necessary organizational
            power and
            authority, and the legal right to own and operate its Properties, to
            lease the
            Properties it operates as lessee and to conduct the business in which
            it is
            currently engaged, (iii) is duly qualified as a foreign entity and in
            good
            standing under the laws of each jurisdiction where its ownership, lease
            or
            operation of Property or the conduct of its business requires such
            qualification, other than in such jurisdictions where the failure to
            be so
            qualified and in good standing has not had and could not have a Material
            Adverse
            Effect, and (iv) is in compliance with all applicable law, except to
            the extent
            that the failure to comply therewith has not had and could not be reasonably
            expected to have a Material Adverse Effect.

           

          (b) It
            has the power and authority and legal right to execute
            and deliver this Guaranty and to perform its obligations hereunder. The
            execution and delivery by it of this Guaranty and the performance of
            its
            obligations hereunder have been duly authorized by proper proceedings.
            No
            consent or authorization of, filing with, notice to or other act by or
            in
            respect of, any Governmental Authority or other Person is required in
            connection
            with its execution and delivery of this Guaranty and performance of its
            obligations hereunder (other than those which have been obtained).

           

          (c) This
            Guaranty constitutes a legal, valid and binding
            obligation of the Guarantor, enforceable against it in accordance with
            its
            terms, except as enforceability may be limited by applicable bankruptcy,


           

          
            
              
              

            

            
              
              

              
              

            

            
              
              
insolvency, reorganization, moratorium or similar laws
              affecting the enforcement of creditors' rights generally and by general
              equitable principles (whether enforcement is sought by proceedings
              in equity or
              at law).

          

           

          (d) The
            execution, delivery and performance of this Guaranty
            will not violate any applicable law or any material agreement, instrument
            or
            undertaking to which any Guarantor is a party or by which it or any of
            its
            Property is bound (collectively, a "Contractual Obligation") of the Guarantor
            (except those as to which waivers or consents have been obtained and
            those which
            could not reasonably be expected to have a Material Adverse Effect),
            and will
            not result in, or require, the creation or imposition of any Lien on
            any of its
            Properties or revenues pursuant to any applicable law or Contractual
            Obligation.

           

          (e) It
            has a substantial economic interest in the Borrowers
            and expects to derive benefits from transactions resulting in the creation
            of
            the Guaranteed Obligations hereby. The Administrative Agent and the Lenders
            may
            rely conclusively on a continuing warranty hereby made, that each Guarantor
            continues to be benefited by the Lenders' extension of credit to the
            Borrowers,
            and neither the Administrative Agent nor the Lenders shall have any duty
            to
            inquire into or confirm the receipt of any such benefits, and this Guaranty
            shall be effective and enforceable by the Administrative Agent and the
            Lenders
            without regard to the receipt, nature or value of any such benefits.

           

          (f) It
            has received a copy of the Credit Agreement.

           

          SECTION
            9. Limitations on Obligations. 

           

          (a)
 The
            provisions of this Guaranty are severable, and in
            any action or proceeding involving any state corporate law, or any state,
            federal or foreign bankruptcy, insolvency, reorganization or other law
            affecting
            the rights of creditors generally, if the obligations of any Guarantor
            under
            this Guaranty would otherwise be held or determined to be avoidable,
            invalid or
            unenforceable on account of the amount of such Guarantor's liability
            under this
            Guaranty, then, notwithstanding any other provision of this Guaranty
            to the
            contrary, the amount of such liability shall, without any further action
            by such
            Guarantor, the Administrative Agent or the Lenders, be automatically
            limited and
            reduced to the highest amount that is valid and enforceable as determined
            in
            such action or proceeding (such highest amount determined hereunder being
            the
            relevant Guarantor's "Maximum Liability"). This Section 9(a) with respect
            to the
            Maximum Liability of any Guarantor is intended solely to preserve the
            rights of
            the Administrative Agent and the Lenders to the maximum extent not subject
            to
            avoidance under applicable law, and neither any Guarantor nor any other
            Person
            or entity shall have any right or claim under this Section 9(a) with
            respect to
            the Maximum Liability, except to the extent necessary so that the obligations
            of
            any Guarantor hereunder shall not be rendered voidable under applicable
            law.

           

          (b) The
            Guarantor agrees that the Guaranteed Obligations may
            at any time and from time to time exceed the Maximum Liability of Guarantor,
            and
            may exceed the aggregate Maximum Liability of any other guarantors, without
            impairing this Guaranty or affecting the rights and remedies of the
            Administrative Agent or 

           

          
            
              
              

            

            
              
              

              
              

            

            
              
              
the Lenders. Nothing in this Section 9(b) shall be construed
              to increase any Guarantor's obligations hereunder beyond its Maximum
              Liability.

          

           

          (c) In
            the event any Guarantor (a "Paying Guarantor") shall
            make any payment or payments under this Guaranty or shall suffer any
            loss as a
            result of any realization upon any collateral granted by it to secure
            its
            obligations under this Guaranty, any other guarantor (each a "Non-Paying
            Guarantor") shall contribute to such Paying Guarantor an amount equal
            to such
            Non-Paying Guarantor's "Pro Rata Share" of such payment or payments made,
            or
            losses suffered, by such Paying Guarantor. For the purposes hereof, each
            Non-Paying Guarantor's "Pro Rata Share" with respect to any such payment
            or loss
            by a Paying Guarantor shall be determined as of the date on which such
            payment
            or loss was made by reference to the ratio of (i) such Non-Paying Guarantor's
            Maximum Liability as of such date (without giving effect to any right
            to
            receive, or obligation to make, any contribution hereunder) or, if such
            Non-Paying Guarantor's Maximum Liability has not been determined, the
            aggregate
            amount of all monies received by such Non-Paying Guarantor from the Borrowers
            after the date hereof (whether by loan, capital infusion or by other
            means) to
            (ii) the aggregate Maximum Liability of all guarantors hereunder (including
            such
            Paying Guarantor) as of such date (without giving effect to any right
            to
            receive, or obligation to make, any contribution hereunder), or to the
            extent
            that a Maximum Liability has not been determined for any guarantors,
            the
            aggregate amount of all monies received by such guarantors from the Borrowers
            after the date hereof (whether by loan, capital infusion or by other
            means).
            Nothing in this Section 9(c) shall affect any Guarantor's or any other
            guarantor's several liability for the entire amount of the Guaranteed
            Obligations (up to such guarantor's Maximum Liability). Each Guarantor
            covenants
            and agrees that its right to receive any contribution under this Guaranty
            from a
            Non-Paying Guarantor shall be subordinate and junior in right of payment
            to all
            the Guaranteed Obligations. The provisions of this Section 9(c) are for
            the
            benefit of the Administrative Agent, the Lenders and the Guarantor and
            may be
            enforced by any one, or more, or all of them in accordance with the terms
            hereof.

           

          SECTION
            10. Notices. Any notice, demand, request or consent
            required or authorized hereunder shall be served in person or delivered
            by U.S.
            certified mail, return receipt requested, addressed as follows:

           

          
            	
                               
                      If to Guarantor:

                  	
                    c/o
                      Unit Corporation

                    1000
                      Kensington Tower I 

                    Tulsa,
                      Oklahoma 74136

                    Fax:
                      (918) 493-7711

                    Attention:
                      General Counsel

                  
	
                               
                      If to the Lenders or the

                               
                      Administrative Agent:

                  	
                    BANK
                      OF OKLAHOMA, N.A.

                    Bank
                      of Oklahoma Tower

                    One
                      Williams Center

                    Tulsa,
                      Oklahoma 74192

                    Attn:
                      Energy Department - 8th Floor

                    Fax:
                      (918) 588-6880

                  


          

          


          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          

          or
            at such other address as the Guarantor or the Administrative
            Agent shall designate for such purpose in a written notice to the other
            parties.
            Notices served in person shall be effective and deemed given when delivered;
            and
            notices sent by certified mail shall be effective and deemed given three
            (3)
            Business Days after being deposited in the U.S. mail, postage prepaid.

           

          SECTION
            11. Survival. All warranties, representations and
            covenants made by the Guarantor herein or in any certificate or other
            instrument
            delivered by it or on its behalf hereunder shall be considered to have
            been
            relied upon by the Lenders and shall survive the execution and delivery
            of this
            Guaranty, regardless of any investigation made by the Administrative
            Agent or
            any of the Lenders. All statements in any such certificate or other instrument
            shall constitute warranties and representations by the Guarantors
            hereunder.

           

          SECTION
            12. Severability. Any remedy or right hereby
            granted which shall be found to be unenforceable as to any Person or
            under any
            circumstance, for any reason, shall in no way limit or prevent the enforcement
            of such remedy or right as to any other Person or circumstances, nor
            shall such
            unenforceability limit or prevent enforcement of any other remedy or
            right
            hereby granted.

           

          SECTION
            13. Collection Costs. The Guarantor agrees to
            reimburse the Administrative Agent upon demand for all reasonable out
            of pocket
            expenses (including reasonable attorneys' fees and legal expenses) incurred
            by
            the Administrative Agent or the Lenders arising out of or in connection
            with the
            enforcement of the Guaranteed Obligations or arising out of or in connection
            with any failure of the Guarantor to fully and timely perform their obligations
            hereunder.

           

          SECTION
            14. Governing Law. This Guaranty is made under and
            shall be governed by the laws of the State of Oklahoma, without giving
            effect to
            conflict of laws principles thereof.

           

          SECTION
            15. Jurisdiction and Venue. All actions or
            proceedings with respect to this Guaranty may be instituted in any state
            or
            federal court sitting in Tulsa County, Oklahoma, and by execution and
            delivery
            of this Guaranty, the Guarantor irrevocably and unconditionally (i) submits
            to
            the nonexclusive jurisdiction (both subject matter and Person) of each
            such
            court, and (ii) waives (a) any objection that the Guarantors may now
            or
            hereafter have to the laying of venue in any of such courts, and (b)
            any claim
            that any action or proceeding brought in any such court has been brought
            in an
            inconvenient forum.

           

          SECTION
            16. Waiver of Jury Trial.
            The Guarantor, the Administrative Agent and the Lenders (by their acceptance
            hereof) hereby voluntarily, knowingly, irrevocably and unconditionally
            waive any
            right to have a jury participate in resolving any dispute (whether based
            upon
            contract, tort or otherwise) between or among the Borrowers or the Guarantor
            and
            the Administrative Agent or the Lenders arising out of or in any way
            related to
            this Guaranty. This Section 16 is a material inducement to the Lenders
            to
            provide the financing described herein or in the Credit
            Agreement.

           

          SECTION
            17. Additional Guarantors. Pursuant to Section
            9.2 of the Credit Agreement, all future Material Subsidiaries of the
            Borrowers
            shall execute and deliver to the Administrative Agent a Guaranty Joinder
            Agreement, the form of which is attached hereto as Schedule I and made
            a part
            hereof. Upon the execution of a Guaranty Joinder 

           

          
            
              
              

            

            
              
              

              
              

            

            
              
              
Agreement, the Material
              Subsidiary shall be deemed to be a Guarantor for all purposes under
              this
              Guaranty and shall subscribe to and agree to be bound by all of the
              terms,
              conditions, agreements, covenants, and undertakings set forth in
              herein.

          

           

          SECTION
            18. Section Headings. The Section and subsection
            headings herein are for convenience only and shall not be deemed part
            of this
            Guaranty.

           

          SECTION
            19. Successors and Assigns. This Guaranty shall be
            binding upon the Guarantor and the Guarantor's successors and assigns
            and shall
            inure to the benefit of the Administrative Agent and the Lenders and
            their
            successors and assigns.

           

          SECTION
            20. Time of the Essence. The Guarantor acknowledges
            that time is of the essence with respect to the Guarantors' obligations
            under
            this Guaranty.

           

          IN
            WITNESS WHEREOF, the Guarantor has caused this Guaranty to be
            duly executed as of the day and year first above written.

           

          [______________________]

           

          By:_____________________________________

          Name:
            __________________________________

          Title:
            ___________________________________

           

          


          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          


          SCHEDULE
            I

           

          GUARANTY
            JOINDER AGREEMENT

           

          THIS
            GUARANTY JOINDER AGREEMENT (this "Joinder"), dated as of
            _________, 200_, is executed by _____________________________, a ____________
            ___________ (the "Additional Guarantor"), in favor of (i) the Lenders
            from time
            to time parties to the Credit Agreement described below and (ii) Bank
            of
            Oklahoma, National Association, as Administrative Agent under the Credit
            Agreement.

           

          RECITALS

           

          A. Unit
            Corporation, a Delaware corporation, Superior
            Pipeline Company, L.L.C., an Oklahoma limited liability company, Unit
            Drilling
            Company, an Oklahoma corporation, Unit Petroleum Company, Inc., an Oklahoma
            corporation, and Unit Texas Drilling, L.L.C., an Oklahoma limited liability
            company (collectively, the "Borrowers"), the Lenders therein named, and
            Bank of
            Oklahoma, National Association, as Administrative Agent, are parties
            to that
            certain First Amended and Restated Senior Credit Agreement dated effective
            as of
            May 24, 2007 (as amended, restated, supplemented or otherwise modified
            from time
            to time, the "Credit Agreement"). Capitalized terms used herein and not
            otherwise defined herein have the respective meanings assigned to them
            in the
            Credit Agreement.

           

          B.
 A
            Material Subsidiary has entered into that certain
            Guaranty Agreement dated effective as of ___________, in favor of the
            Lender and
            the Administrative Agent (as amended, restated, supplemented or otherwise
            modified from time to time, the "Guaranty"), pursuant to which such Material
            Subsidiary absolutely and unconditionally guaranteed, the full and punctual
            payment and performance of the Guaranteed Obligations, as more particularly
            set
            forth in the Guaranty.

           

          C.
 The
            Additional Guarantor is a Material Subsidiary of the
            Borrowers, and pursuant to Section 9.2 of the Credit Agreement, the Borrowers
            are required to cause the Additional Guarantor to guarantee to the
            Administrative Agent the prompt payment and performance of the Guaranteed
            Obligations. The Additional Guarantor desires to execute and deliver
            this
            Joinder to satisfy such requirement.

           

          NOW,
            THEREFORE, in consideration of the premises and other good
            and valuable consideration, the receipt and sufficiency of which are
            hereby
            acknowledged, the Additional Guarantor agrees as follows:

           

          SECTION
            1. Guaranty. The Additional Guarantor hereby
            absolutely and unconditionally guarantees, jointly and severally, as
            a primary
            obligor and not as surety, the full and punctual payment (whether at
            stated
            maturity, upon acceleration or early termination or otherwise, and at
            all times
            thereafter) and performance of the Guaranteed Obligations (as such term
            is
            defined in the Guaranty), including, without limitation, any such Guaranteed
            Obligations incurred or accrued during the pendency of any bankruptcy,
            insolvency, receivership or other similar proceeding, whether or not
            allowed or
            allowable in such proceeding. This Guaranty is a guaranty of payment
            and not
            just of collectibility and is in no way conditioned or contingent upon
            any
            attempt to collect from the Borrowers or upon any other event, 

           

          
            
              
              

            

            
              
              

              
              

            

            
              
              
contingency or circumstance
              whatsoever. If for any reason whatsoever the Borrowers shall fail or
              be unable
              duly, punctually and fully to pay such amounts as and when the same
              shall become
              due and payable, the Guarantors, without demand, presentment, protest
              or notice
              of any kind, will forthwith pay or cause to be paid such amounts to
              the
              Administrative Agent under the terms of the Credit Agreement, any Note
              or other
              relevant Loan Document, in lawful money of the United States, at the
              place
              specified in the Credit Agreement, or perform or comply with the same
              or cause
              the same to be performed or complied with, together with interest (to
              the extent
              provided for under the Credit Agreement) on any amount due and owing
              from the
              Borrowers. 

          

           

          SECTION
            2. Binding Effect. This Joinder shall become
            effective when it shall have been executed by the Additional Guarantor
            and
            thereafter shall be binding upon the Additional Guarantor and shall inure
            to the
            benefit of the Lenders. Upon the effectiveness of this Joinder, the Additional
            Guarantor shall be deemed to be a Guarantor for all purposes under the
            Guaranty
            and shall subscribe to and agree to be bound by all of the terms, conditions,
            agreements, covenants, and undertakings set forth in the Guaranty, and
            this
            Joinder shall be deemed to be a part of and shall be subject to all the
            terms
            and conditions of the Guaranty. The Additional Guarantor shall not have
            the
            right to assign its rights hereunder or any interest herein without the
            prior
            written consent of the Administrative Agent. 

           

          SECTION
            3. CHOICE OF LAW. THIS JOINDER SHALL BE
            GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE INTERNAL LAWS (AND
            NOT THE
            LAW OF CONFLICTS) OF THE STATE OF OKLAHOMA.

           

          IN
            WITNESS WHEREOF, the Additional Guarantor has caused this
            Joinder to be duly executed and delivered by its duly authorized officer
            as of
            the date first above written.

           

          [______________________]

           

          


           

          By:_____________________________________

          Name:
            __________________________________

          Title:
            ___________________________________

           

          


          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          


          SCHEDULE
            1

           

          PRICING
            SCHEDULE

           

          


          
            	
                    Applicable

                    Margin

                  	
                    Level
                      I

                    Status

                  	
                    Level
                      II

                    Status

                  	
                    Level
                      III

                    Status

                  	
                    Level
                      IV

                    Status

                  
	
                    Eurodollar
                      Rate

                  	
                    1.00%

                  	
                    1.25%

                  	
                    1.50%

                  	
                    1.75%

                  
	
                    Floating
                      Rate

                  	
                    0.00%

                  	
                    0.00%

                  	
                    0.00%

                  	
                    0.00%

                  


          

          


          


          
            	
                    Applicable

                    Margin

                  	
                    Level
                      I

                    Status

                  	
                    Level
                      II

                    Status

                  	
                    Level
                      III

                    Status

                  	
                    Level
                      IV

                    Status

                  
	
                    Commitment
                      Fee Rate 

                  	
                    0.250%

                  	
                    0.300%

                  	
                    0.350%

                  	
                    0.375%

                  


          

          


          For
            the purposes of this Schedule, the following terms have the
            following meanings, subject to the final paragraph of this Schedule:

           

          "Level
            I Status" exists at any date if the Borrowing Base Usage
            Percentage on such date is less than 50%.

           

          "Level
            II Status" exists at any date if the Borrowing Base Usage
            Percentage on such date is greater than or equal to 50% and less than
            75%.

           

          "Level
            III Status" exists at any date if the Borrowing Base Usage
            Percentage on such date is greater than or equal to 75% and less than
            90%.

           

          "Level
            IV Status" exists at any date if the Borrowing Base Usage
            Percentage on such date is greater than or equal to 90%.

           

          "Status"
            means either Level I Status, Level II Status, Level III
            Status or Level IV Status.

           

          The
            Applicable Margin and Commitment Fee Rate will be determined
            on a daily basis in accordance with the foregoing table based on the
            Borrowing
            Base Usage Percentage on such day.

           

          Letter
            of Credit Fees: Issuance Fees are payable quarterly in
            advance, determined as of the LC issue date based on the applicable Margin
            (Eurodollar Rate column) for Eurodollar Loans on the stated amount of
            the LC and
            an LC fronting fee of 0.125% per annum will be paid to the LC Issuer
            concurrent
            with execution.

           

          


          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          


          SCHEDULE
            2

           

          LENDERS
            SCHEDULE

           

          


          
            	
                    Lender

                     

                  	
                    Aggregate


                    Commitment
                      Amount

                     

                  	
                    Maximum
                      Credit Amount

                     

                  	
                    Pro
                      Rata Share

                     

                  
	
                    Bank
                      of Oklahoma, N. A.

                     

                  	
                    $51,562,500.00

                     

                  	
                    $75,000,000.00

                     

                  	
                    18.75%

                     

                  
	
                    Bank
                      of America, N. A. 

                     

                  	
                    $
                      51,562,500.00

                     

                  	
                    $75,000,000.00

                     

                  	
                    18.75%

                     

                  
	
                    BMO

                     

                  	
                    $51,562,500.00

                     

                  	
                    $75,000,000.00

                     

                  	
                    18.75%

                     

                  
	
                    Compass
                      Bank

                     

                  	
                    $34,375,000.00

                     

                  	
                    $50,000,000.00

                     

                  	
                    12.50%

                     

                  
	
                    Comerica
                      Bank

                     

                  	
                    $24,062,500.00

                     

                  	
                    $35,000,000.00

                     

                  	
                    08.75%

                     

                  
	
                    Fortis
                      Capital Corp.

                     

                  	
                    $24,062,500.00

                     

                  	
                    $35,000,000.00

                     

                  	
                    08.75%

                     

                  
	
                    Calyon
                      New York Branch

                     

                  	
                    $24,062,500.00

                     

                  	
                    $35,000,000.00

                     

                  	
                    08.75%

                     

                  
	
                    Sterling
                      Bank

                     

                  	
                    $13,750,000.00

                     

                  	
                    $20,000,000.00

                     

                  	
                    05.00%

                     

                  
	
                    TOTAL


                     

                  	
                    $275,000,000.00

                     

                  	
                    $400,000,000.00

                     

                  	
                    100.00%

                     

                  


          

          


          


          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          


          SCHEDULE
            3

           

          DISCLOSURE
            SCHEDULE

           

          1. Section
            5.8 -
            Subsidiaries

           

           

          
            	 	 State/Country  	 Ownership
                    Interest
	 Name	 of
                    Incorporation 	 by
                    Borrower
	 	 	 
	 Unit
                    Petroleum Company   	 Oklahoma	 100%
                    UC
	 Unit
                    Drilling Company   	 Oklahoma	 100%
                    UC
	 Unit
                    Texas Company    	 Oklahoma	 100%
                    UPC
	 Unit
                    Drilling and Exploration Company 	 Delaware 	 100%
                    UC
	 Petroleum
                    Supply Company   	 Oklahoma	 100%
                    UC
	 Unit
                    Energy Canada Inc.	 Alberta,
                    Canada 	 100%
                    UC
	 Superior
                    Pipeline Company LLC	 Oklahoma	 100%
                    UC
	 Unit
                    Drilling Company International 	 Cayman
                    Islands 	 100%
                    UDC
	 Unit
                    General LLC    	 Oklahoma 	 100%
                    UPC
	 Unit
                    Limited LLC    	 Oklahoma	 100%
                    UPC
	 UDC
                    General LLC    	 Oklahoma	 100%
                    UDC
	 UDC
                    Limited LLC    	 Oklahoma 	 100%
                    UDC
	 Unit
                    Texas Drilling, L.L.C.	 	 
	 UTD
                    General, L.L.C.	 	 
	 UTD
                    Limited, L.L.C.	 	 
	 UTD
                    Limited Partnership	 	 
	 GTS
                    Drilling Company	 	 
	 UTD
                    Texas LP	 	 
	 Brighton
                    Energy, L.L.C.	 	 
	 Unit
                    Texas LP	 	 
	 Superior
                    Texas GP, L.L.C.	 	 
	 Superior
                    Oklahoma, L.L.C.	 	 
	 Berkshire
                    Energy, L.L.C.	 	 
	 Superior
                    Gathering, LP	 	 


          

           

           

          2. Section
            7.2 - Existing
            Indebtedness

          


          King
            P. Kirchner Separation Agreement

          Separation
            obligations under employee benefit plans

          Customary
            gas balancing obligations

          Prepayments
            for contract drilling services

          Matters
            disclosed in Item 7 of Unit Corporation's 10-K for
            12-31-06

          Unit's
            consolidated financial statements as filed in its Form 10-Q
            for the quarter ended March 31, 2007

          


          3. Section
            7.6(v) - Existing
            Liens

          


          None

          


          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          

          4. Section
            7.5 - Investments


          


          Investment
            in public and private limited partnerships sponsored by
            Borrowers

          Superior
            Investment in Driscoll System, L.P. 

          


           

          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          

          



          SCHEDULE
            4

           

          ENVIRONMENTAL
            MATTERS

           

          None.

           

          


          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          


          SCHEDULE
            5

           

          RATE
            MANAGEMENT TRANSACTIONS

           

          Natural
            Gas - Hedge transaction for 10,000 mmBtus/day dated
            December 15, 2006, effective January 1, 2007 and terminating December
            31, 2007
            with Bank of Montreal

           

          Natural
            Gas - Hedge transaction for 10,000 mmBtus/day dated
            January 31, 2007, effective March 1, 2007 and terminating December 31,
            2007 with
            Bank of Montreal

           

          Natural
            Gas - Hedge transaction for 10,000 mmBtus/day dated
            February 2, 2007, effective March 1, 2007 and terminating December 31,
            2007 with
            Bank of Montreal

           

          Interest
            Rate-Swap Transaction for $50,000,000 dated February 25,
            2005, effective March 1, 2005, and terminating January 30, 2008, with
            Bank of
            Oklahoma, National Association

           

          


           

          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          

          


          



          SCHEDULE
            6

           

          EXCLUDED
            ACCOUNTS

           

          
            	
                     Account
                      Name

                  	
                     Checking
                      Account #

                  	
                     Investment
                      Account

                  	
                     GB
                      Reserve Account

                  
	 	 	 	 
	
                     1979
                      O&G Program

                  	
                     101174868

                  	
                     700148623

                  	 
	 1984
                    Limited Partnership	
                     102657437

                  	
                     700148491

                  	 
	 1986
                    Energy Income Ltd Partnership	
                     207923104

                  	
                     700147380

                  	 
	 2000
                    Employee O&G Partnership	
                     208331182

                  	
                     700170326

                  	 
	 2001
                    Employee O&G Partnership	
                     208335758

                  	
                     700171426

                  	 
	 2002
                    Employee O&G Partnership	
                     208341445

                  	
                     700173010

                  	 
	 2003
                    Employee O&G Partnership	
                     208346131

                  	
                     700175408

                  	 
	 2004
                    Employee O&G Partnership	
                     208351092

                  	
                     700176453

                  	 
	 Consolidated
                    Employee O&G 	 	 	 
	  
                    Partnership	
                     103840773

                  	
                     810039724

                  	 
	 Esco-Boston
                    86-1 Limited Partnership	
                     207928648

                  	
                     700149822

                  	
                     700149877

                  
	 Questa
                    1985 Program Ltd	
                     208332084

                  	
                     700106218

                  	 
	 Unidentified
                    Mineral Owner	
                     103570184

                  	
                     N/A

                  	 
	 2005
                    Employee O&G Partnership	
                     208357219

                  	
                     208357208

                  	 
	 2006
                    Employee O&G Partnership	
                     208363071

                  	
                     208363082

                  	 
	 2007
                    Employee O&G Partnership	
                     209914929

                  	
                     700181117

                  	 
	 PetroCorp
                    Escrow Account	 	
                     7180011341

                  	 


          

           

          


           

          
            
              
              

            

            
              
              

              
              

            

            
              
              

            

          


          SCHEDULE
            7

           

          CONTINGENT
            OBLIGATIONS

           

          - Benefits
            payable under Health Plans

           

          - Benefits
            payable under Separation Benefit Plans

           

          - Benefits
            payable under Workers’ Compensation plans

           

          - Benefits
            payable under Salary Deferral Plans

           

          - Operating
            Leases

           

          -
            Contingent Obligations referenced in the consolidated financial
            statements of Unit included in its annual report on Form 10-K filed with
            the SEC
            for the year ended December 31, 2007 and its quarterly report on Form
            10-Q filed
            with the SEC for the quarter ended March 31, 2007