EXHIBIT 2.3


























**PURCHASE
      AND SALE AGREEMENT**





**BETWEEN**





**ANADARKO
      E&P COMPANY LP AND**


**KERR-M** **c** **GEE
      OIL & GAS ONSHORE LP,**





**AS
      SELLER**








**AND**





**ENERVEST
      ENERGY INSTITUTIONAL FUND X-A, L.P.,**


**ENERVEST
      ENERGY INSTITUTIONAL FUND X-WI, L.P.,**


**ENERVEST
      ENERGY INSTITUTIONAL FUND XI-A, L.P.,**


**ENERVEST
      ENERGY INSTITUTIONAL FUND XI-WI, L.P.,**


**ENERVEST
      MANAGEMENT PARTNERS, LTD.,**


**WACHOVIA
      INVESTMENT HOLDINGS, LLC, and**


**EV
      PROPERTIES, L.P.**





**AS
      PURCHASER**





Executed
      on April 13, 2007







Page
          1 of
          65






TABLE
      OF
      CONTENTS


DEFINITIONS
                
                7PURCHASE
                    AND SALE AGREEMENT
                13RECITALS
                
                13ARTICLE
                    1 PURCHASE AND SALE
                13Section
                    1.1
                Purchase
                    and Sale.
                13Section
                    1.2
                Assets.
                14Section
                    1.3
                Excluded
                    Assets.
                15Section
                    1.4
                Effective
                    Time; Proration of Costs and Revenues.
                16Section
                    1.5
                Delivery
                    and Maintenance of Records.
                17ARTICLE
                    2 PURCHASE PRICE
                
                18Section
                    2.1
                Purchase
                    Price.
                18Section
                    2.2
                Adjustments
                    to Purchase Price.
                18Section
                    2.3
                Allocation
                    of Purchase Price for Tax Purposes.
                19Section
                    2.4
                Deposit.
                20ARTICLE
                    3 TITLE MATTERS
                
                20Section
                    3.1
                Seller’s
                    Title.
                20Section
                    3.2
                Definition
                    of Defensible Title.
                20Section
                    3.3
                Definition
                    of Permitted Encumbrances.
                22Section
                    3.4
                Notice
                    of Title Defect Adjustments.
                23Section
                    3.5
                Casualty
                    or Condemnation Loss.
                26Section
                    3.6
                Limitations
                    on Applicability.
                27Section
                    3.7
                Government
                    Approvals Respecting Assets
                27ARTICLE
                    4 ENVIRONMENTAL MATTERS
                
                28Section
                    4.1
                Assessment.
                28Section
                    4.2
                NORM,
                    Wastes and Other Substances.
                29Section
                    4.3
                Environmental
                    Defects.
                29Section
                    4.4
                Inspection
                    Indemnity.
                30ARTICLE
                    5 REPRESENTATIONS AND WARRANTIES OF SELLER
                31Section
                    5.1
                Generally.
                31Section
                    5.2
                Existence
                    and Qualification.
                31Section
                    5.3
                Power.
                31Section
                    5.4
                Authorization
                    and Enforceability.
                31Section
                    5.5
                No
                    Conflicts.
                32Section
                    5.6
                Liability
                    for Brokers’ Fees.
                32Section
                    5.7
                Litigation.
                32Section
                    5.8
                Taxes
                    and Assessments.
                32Section
                    5.9
                Compliance
                    with Laws.
                33Section
                    5.10
                Contracts.
                33Section
                    5.11
                Payments
                    for Hydrocarbon Production.
                33Section
                    5.12
                Governmental
                    Authorizations.
                33Section
                    5.13
                Preference
                    Rights and Transfer Requirements.
                34Section
                    5.14
                [RESERVED].
                34Section
                    5.15
                Outstanding
                    Capital Commitments.
                34Section
                    5.16
                Imbalances.
                34Section
                    5.17
                Condemnation.
                34Section
                    5.18
                Bankruptcy.
                35Section
                    5.19
                PUHCA/NGA.
                35Section
                    5.20
                Investment
                    Company.
                35
   Page
              2 of
              65
  ARTICLE
                    6 REPRESENTATIONS AND WARRANTIES OF PURCHASER
                35Section
                    6.1
                Existence
                    and Qualification.
                35Section
                    6.2
                Power.
                35Section
                    6.3
                Authorization
                    and Enforceability.
                36Section
                    6.4
                No
                    Conflicts.
                36Section
                    6.5
                Liability
                    for Brokers’ Fees.
                36Section
                    6.6
                Litigation.
                36Section
                    6.7
                Financing.
                36Section
                    6.8
                Several
                    Liability.
                37Section
                    6.9
                Limitation.
                37Section
                    6.10
                SEC
                    Disclosure.
                37Section
                    6.11
                Bankruptcy.
                37Section
                    6.12
                Qualification.
                37ARTICLE
                    7 COVENANTS OF THE PARTIES
                
                38Section
                    7.1
                Access.
                38Section
                    7.2
                Government
                    Reviews.
                38Section
                    7.3
                Notification
                    of Breaches.
                38Section
                    7.4
                Letters-in-Lieu;
                    Assignments; Operatorship.
                39Section
                    7.5
                Public
                    Announcements.
                39Section
                    7.6
                Operation
                    of Business.
                39Section
                    7.7
                Hedges.
                40Section
                    7.8
                Preference
                    Rights and Transfer Requirements.
                41Section
                    7.9
                Tax
                    Matters.
                43Section
                    7.10
                Further
                    Assurances.
                43Section
                    7.11
                [RESERVED].
                43Section
                    7.12
                [RESERVED].
                43Section
                    7.13
                [RESERVED].
                43Section
                    7.14
                Insurance.
                43ARTICLE
                    8 CONDITIONS TO CLOSING
                
                44Section
                    8.1
                Conditions
                    of Seller to Closing.
                44Section
                    8.2
                Conditions
                    of Purchaser to Closing.
                45ARTICLE
                    9 CLOSING
                
                46Section
                    9.1
                Time
                    and Place of Closing.
                46Section
                    9.2
                Obligations
                    of Seller at Closing.
                46Section
                    9.3
                Obligations
                    of Purchaser at Closing.
                47Section
                    9.4
                Closing
                    Payment & Post-Closing Purchase Price Adjustments.
                47ARTICLE
                    10 TERMINATION
                
                48Section
                    10.1
                Termination.
                48Section
                    10.2
                Effect
                    of Termination.
                48Section
                    10.3
                Distribution
                    of Deposit Upon Termination.
                49ARTICLE
                    11 POST-CLOSING OBLIGATIONS; INDEMNIFICATION; LIMITATIONS; DISCLAIMERS
                    AND
                    WAIVERS
                49Section
                    11.1
                Receipts.
                49Section
                    11.2
                Expenses.
                49Section
                    11.3
                Assumed
                    Seller Obligations.
                50Section
                    11.4
                Indemnities.
                51Section
                    11.5
                Indemnification
                    Actions.
                52Section
                    11.6
                Release.
                54Section
                    11.7
                Limitation
                    on Actions.
                54Section
                    11.8
                Disclaimers.
                55Section
                    11.9
                Waivers.
                56
  Page
              3 of
              65
  Section
                    11.9.1
                Waiver
                    of Trade Practices Acts.
                56Section
                    11.9.2
                Redhibition
                    Waiver.
                56Section
                    11.10
                Recording.
                56ARTICLE
                    12 MISCELLANEOUS
                
                57Section
                    12.1
                Counterparts.
                57Section
                    12.2
                Notice.
                57Section
                    12.3
                Sales
                    or Use Tax Recording Fees and Similar Taxes and Fees.
                59Section
                    12.4
                Expenses.
                59Section
                    12.5
                Change
                    of Name.
                59Section
                    12.6
                Replacement
                    of Bonds, Letters of Credit and Guarantees.
                59Section
                    12.7
                Governing
                    Law and Venue.
                60Section
                    12.8
                Captions.
                60Section
                    12.9
                Waivers.
                60Section
                    12.10
                Assignment.
                60Section
                    12.11
                Entire
                    Agreement.
                60Section
                    12.12
                Amendment.
                60Section
                    12.13
                No
                    Third-Party Beneficiaries.
                61Section
                    12.14
                References.
                61Section
                    12.15
                Construction.
                61Section
                    12.16
                Limitation
                    on Damages
                61Section
                    12.17
                Conspicuousness.
                62Section
                    12.18
                Severability.
                62Section
                    12.19
                Time
                    of Essence.
                62





Page
          4 of
          65




**EXHIBITS**


**Exhibit
                  “A”**
              Properties**Exhibit
                  “A-1”**
              Wells
                  and Units**Exhibit
                  “A-2”**
              Equipment**Exhibit
                  “B”**
              Conveyance**Exhibit
                  “C”**
              Indemnity
                  Agreement
  **SCHEDULES**
  **Schedule
                  1.1**
              Purchaser
                  Share**Schedule
                  1.2(d)**
              Contracts**Schedule
                  1.2(e)**
              Surface
                  Contracts**Schedule
                  1.2(g)**
              Pipelines**Schedule
                  1.3(e)**
              Excluded
                  Items**Schedule
                  1.4**
              Effective
                  Time; Proration of Costs and Revenues**Schedule
                  2.3**
              Allocation
                  of Purchase Pricefor Tax Purposes**Schedule
                  5.7**
              Litigation**Schedule
                  5.8**
              Taxes
                  and Assessments**Schedule
                  5.9**
              Compliance
                  with Laws**Schedule
                  5.10(a)**
              Contract
                  Matters**Schedule
                  5.10(b)**
              Certain
                  Contracts**Schedule
                  5.11**
              Hydrocarbon
                  Production Payments**Schedule
                  5.12**
              Governmental
                  Authorizations**Schedule
                  5.13**
              Preference
                  Rights and Transfer Requirements
  Page
            5 of
            65
 **Schedule
                  5.15**
              Outstanding
                  Capital Commitments**Schedule
                  5.16**
              Imbalance**Schedule
                  7.6**
              Operation
                  of Business**Schedule
                  7.7**
              Hedging
                  Transactions




Page
          6 of
          65




**DEFINITIONS** ****




“Adjustment
      Period” has the meaning set forth in **Section
      2.2(a)** .




“Adjusted
      Purchase Price” shall mean the Purchase Price after calculating and applying the
      adjustments set forth in **Section
      2.2** .




“AEPC”
      has the meaning set forth in the preamble of this Agreement.





"AFE"
      means authority for expenditure.





“Affiliates”
      with respect to any Person, means any person that directly or indirectly
      controls, is controlled by or is under common control with such
      Person.




“Agreed
      Interest Rate” means simple interest calculated at the rate of five percent (5%)
      per annum.




“Agreement”
      means this Purchase and Sale Agreement.





“Aggregate
      Benefit Deductible” has the meaning set forth in **Section
      3.4(j)** .





“Aggregate
      Deductible” has the meaning set forth in **Section
      3.4(j)** .




“Allocated
      Value” has the meaning set forth in **Section
      3.4(a)** .




"Assessment"
      has the meaning set forth in **Section
      4.1** .





“Assets”
      has the meaning set forth in **Section
      1.2** .




“Assumed
      Seller Obligations” has the meaning set forth in **Section
      11.3** .





“Business
      Day” means each calendar day except Saturdays, Sundays, and Federal
      holidays.




“Claim”
      or “Claims” has the meaning set forth in **Section
      11.4(a)** .





“Claim
      Notice” has the meaning set forth in **Section
      11.5(b)** .




“Closing”
      has the meaning set forth in **Section
      9.1(a)** .




“Closing
      Date” has the meaning set forth in **Section
      9.1(b)** .




“Closing
      Payment” has the meaning set forth in **Section
      9.4(a)** .




“Code”
      has the meaning set forth in **Section
      2.3** .




“Confidentiality
      Agreement” has the meaning set forth in **Section
      7.1** .




“Contracts”
      has the meaning set forth in **Section
      1.2(d)** .




“Conveyance”
      has the meaning set forth in **Section
      3.1(b)** .




Page
          7 of
          65





“Counterparties”
      has the meaning set forth in **Section
      7.7(a)** .




“Cure
      Period” has the meaning set forth in **Section
      3.4(c)** .




“Defensible
      Title” has the meaning set forth in **Section
      3.2** .





“Deposit”
      has the meaning set forth in **Section
      2.4** .





"DTPA"
      has the meaning set forth in **Section
      11.9.1** .




“Effective
      Time” has the meaning set forth in **Section
      1.4(a)** .





“EnerVest”
      has the meaning set forth in the preamble of this Agreement.





“EnerVest
      X-A” has the meaning set forth in the preamble of this Agreement.





“EnerVest
      X-WI” has the meaning set forth in the preamble of this Agreement.





“EnerVest
      XI-A” has the meaning set forth in the preamble of this Agreement.





“EnerVest
      XI-WI” has the meaning set forth in the preamble of this Agreement.





“Environmental
      Defect” has the meaning set forth in **Section
      4.3(a)** .





“Environmental
      Defect Amount” has the meaning set forth in **Section
      4.3(a)** .





“Environmental
      Defect Notice” has the meaning set forth in **Section
      4.3(a)** .





“Environmental
      Laws” means, as the same may have been amended, the Comprehensive Environmental
      Response, Compensation and Liability Act, 42 U.S.C. § 9601 et
      seq .;
      the
      Resource Conservation and Recovery Act, 42 U.S.C. § 6901 et
      seq .;
      the
      Federal Water Pollution Control Act, 33 U.S.C. § 1251 et
      seq .;
      the
      Clean Air Act, 42 U.S.C. § 7401 et
      seq .
      the
      Hazardous Materials Transportation Act, 49 U.S.C. § 1471 et
      seq .;
      the
      Toxic Substances Control Act, 15 U.S.C. §§ 2601 through 2629; the Oil Pollution
      Act, 33 U.S.C. § 2701 et
      seq .;
      the
      Emergency Planning and Community Right-to-Know Act, 42 U.S.C. § 11001 et
      seq .;
      the
      Safe Drinking Water Act, 42 U.S.C. §§ 300f through 300j; the Federal
      Insecticide, Fungicide and Rodenticide Act, 7 U.S.C. § 136 et seq.; the
      Occupational Safety and Health Act, 29 U.S.C. § 651 et seq.; the Atomic Energy
      Act, 42 U.S.C. § 2011 et seq.; and all applicable related law, whether local,
      state, territorial, or national, of any Governmental Body having jurisdiction
      over the property in question addressing pollution or protection of human
      health, safety, natural resources or the environment and all regulations
      implementing the foregoing.





“Environmental
      Liabilities” shall mean any and all environmental response costs (including
      costs of remediation), damages, natural resource damages, settlements,
      consulting fees, expenses, penalties, fines, orphan share, prejudgment and
      post-judgment interest, court costs, attorneys’ fees, and other liabilities
      incurred or imposed (i) pursuant to any order, notice of responsibility,
      directive (including requirements embodied in Environmental Laws), injunction,
      judgment or similar act (including settlements) by any Governmental Body or
      court of competent jurisdiction to the extent arising out of any violation
      of,
      or remedial obligation under, any Environmental Laws which are attributable
      to
      the ownership or operation of the Assets prior to the Effective Time or (ii)
      pursuant to any claim or cause of action by a Governmental Body or other Person
      for personal injury, property damage, damage to natural resources, remediation
      or response costs to the extent arising out of any violation of, or any
      remediation obligation under, any Environmental Laws which is attributable
      to
      the ownership or operation of the Assets prior to the Effective Time.




Page
          8 of
          65




“Equipment”
      has the meaning set forth in **Section
      1.2(f)** .




“EV
      Properties” has the meaning set forth in the preamble of this
      Agreement.





“Excluded
      Assets” has the meaning set forth in **Section
      1.3** .




“Governmental
      Authorizations” has the meaning set forth in **Section
      5.12** .




“Governmental
      Body” or “Governmental Bodies” means any federal, state, local, municipal, or
      other governments; any governmental, regulatory or administrative agency,
      commission, body or other authority exercising or entitled to exercise any
      administrative, executive, judicial, legislative, police, regulatory or taxing
      authority or power; and any court or governmental tribunal.





“Hedging
      Transactions” has the meaning set forth in **Section
      7.7(a)** .





"HSR
      Act"
      means the Hart-Scott Rodino Antitrust Improvements Act of 1976.





“Hydrocarbons”
      means oil, gas, condensate and other gaseous and liquid hydrocarbons or any
      combination thereof and sulphur extracted from hydrocarbons.




“Imbalance”
      or “Imbalances” means over-production of Hydrocarbons or under-production of
      Hydrocarbons or over-deliveries or under-deliveries with respect to Hydrocarbons
      produced from or allocated to the Assets, regardless of whether such
      over-production of Hydrocarbons or under-production of Hydrocarbons or
      over-deliveries or under-deliveries arise at the platform, wellhead, pipeline,
      gathering system, transportation or other location.





“Indemnified
      Party” has the meaning set forth in **Section
      11.5(a)** .




“Indemnifying
      Party” has the meaning set forth in **Section
      11.5(a)** .





“Indemnity
      Claim” has the meaning set forth in **Section
      11.5(b)** .





“Independent
      Expert” has the meaning set forth in **Section
      4.3(e)** .





“Individual
      Benefit Deductible” has the meaning set forth in **Section
      3.4(j)** .





“Individual
      Environmental Deductible” has the meaning set forth in **Section
      4.3(f)** .





“Individual
      Title Deductible” has the meaning set forth in **Section
      3.4(j)** .





“Invasive
      Activity” has the meaning set forth in **Section
      4.1.**





“KMOG”
      has the meaning set forth in the preamble of this Agreement.




“Lands”
      has the meaning set forth in **Section
      1.2(a)** .




Page
          9 of
          65




“Laws”
      means all statutes, laws, rules, regulations, ordinances, orders, and codes
      of
      Governmental Bodies.




“Leases”
      has the meaning set forth in **Section
      1.2(a)** .





“Lowest
      Cost Response” means the response required or allowed under Environmental Laws
      that addresses the condition present at the lowest cost (considered as a whole
      taking into consideration any material negative impact such response may have
      on
      the operations of the relevant Assets and any potential material additional
      costs or liabilities that may likely arise as a result of such response) as
      compared to any other response that is required or allowed under Environmental
      Laws.




“Material
      Adverse Effect” means any effect that is material and adverse to the ownership,
      operation or value of the Assets, taken as a whole, and as currently operated;
      provided, however, that “Material Adverse Effect” shall not include (i) any
      effect to the extent resulting from the announcement of the entering into the
      transactions contemplated by this Agreement; (ii) any effect resulting from
      changes in general market, economic, financial or political conditions or any
      outbreak of hostilities or war, (iii) any effect that affects the Hydrocarbon
      exploration, production, development, processing, gathering and/or
      transportation industry generally (including changes in commodity prices or
      general market prices in the Hydrocarbon exploration, production, development,
      processing, gathering and/or transportation industry generally), and (iv) any
      effect resulting from a change in Laws or regulatory policies.




“Net
      Revenue Interest” has the meaning set forth in **Section
      3.2(a)** .





“Non-Operated
      Assets” means all Assets other than the Seller Operated Assets.





"NORM"
      means naturally occurring radioactive material.




“Permitted
      Encumbrances” has the meaning set forth in **Section
      3.3** .




“Person”
      means any individual, firm, corporation, partnership, limited liability company,
      joint venture, association, trust, unincorporated organization, Governmental
      Body or any other entity.




“Preference
      Property” has the meaning set forth in **Section
      7.8(b)** .




“Preference
      Right” means any right or agreement that enables any Person to purchase or
      acquire any Asset or any interest therein or portion thereof as a result of
      or
      in connection with (i) the sale, assignment or other transfer of any Asset
      or
      any interest therein or portion thereof or (ii) the execution or delivery of
      this Agreement or the consummation or performance of the terms and conditions
      contemplated by this Agreement.




“Pipelines”
      has the meaning set forth in **Section
      1.2(g)** .




“Properties”
      has the meaning set forth in **Section
      1.2(c)** .




“Property
      Costs” has the meaning set forth in **Section
      1.4(b)** .




“Purchase
      Price” has the meaning set forth in **Section
      2.1** .




Page
          10 of
          65




“Purchaser”
      has the meaning set forth in the preamble of this Agreement.





"Purchaser
      Indemnitees" shall mean Purchaser, Purchaser’s Affiliates, joint owners and
      venturers, co-lessees and partners, and Purchaser’s contractors and each of
      their respective officers, directors, employees, agents, representatives,
      insurers, subcontractors, successors and permitted assigns.




"Purchaser
      Share" has the meaning set forth in **Section
      1.1** .




“Records”
      has the meaning set forth in **Section
      1.2(i)** .




“REGARDLESS
      OF FAULT” has the meaning set forth in **Section
      11.4(a)** .





“Retained
      Asset” has the meaning set forth in **Section
      7.8(d)** .





“Royalty
      Amounts” has the meaning set forth in **Section
      11.3** .




“Seller”
      has the meaning set forth in the preamble of this Agreement.




"Seller
      Indemnitees" shall mean Seller, Seller’s Affiliates, joint owners and venturers,
      co-lessees and partners, and Seller’s contractors, and each of their respective
      officers, directors, employees, agents, representatives, insurers,
      subcontractors, successors and permitted assigns.




“Seller
      Operated Assets” shall mean Assets operated by Seller.





“Surface
      Contracts” has the meaning set forth in **Section
      1.2(e)** .




“Tax
      Allocated Value” has the meaning set forth in **Section
      2.3** .





“Taxes”
      means all federal, state, local, and foreign income, profits, franchise, sales,
      use, ad valorem, property, severance, production, excise, stamp, documentary,
      real property transfer or gain, gross receipts, goods and services,
      registration, capital, transfer, or withholding taxes or other governmental
      fees
      or charges imposed by any taxing authority, including any interest, penalties
      or
      additional amounts which may be imposed with respect thereto.




“Tax
      Returns” has the meaning set forth in **Section
      5.8** .




“Title
      Arbitrator” has the meaning set forth in **Section
      3.4(i)** .




“Title
      Benefit” has the meaning set forth in **Section
      3.2** .




“Title
      Benefit Amount” has the meaning set forth in **Section
      3.4(e)** .




“Title
      Benefit Notice” has the meaning set forth in **Section
      3.4(b)** .




“Title
      Claim Date” has the meaning set forth in **Section
      3.4(a)** .




“Title
      Defect” has the meaning set forth in **Section
      3.2** .




“Title
      Defect Amount” has the meaning set forth in **Section
      3.4(d)(i)** .




Page
          11 of
          65




“Title
      Defect Notice” has the meaning set forth in **Section
      3.4(a)** .




“Title
      Defect Property” has the meaning set forth in **Section
      3.4(a)** .





“Transfer
      Requirement” means any consent, approval, authorization or permit of, or filing
      with or notification to, any Person which is required to be obtained, made
      or
      complied with for or in connection with any sale, assignment or transfer of
      any
      Asset or any interest therein, other than any consent of, notice to, filing
      with, or other action by Governmental Bodies in connection with the sale or
      conveyance of oil and/or gas leases or interests therein or Surface Contracts
      or
      interests therein, if they are not required prior to the assignment of such
      oil
      and/or gas leases, Surface Contracts or interests or they are customarily
      obtained subsequent to the sale or conveyance (including consents from state
      agencies).




“Units”
      has the meaning set forth in **Section
      1.2(c)** .





“UTPCPL”
      has the meaning set forth in **Section
      11.9.1** .





“Wachovia”
      has the meaning set forth in the preamble of this Agreement.





“Wells”
      has the meaning set forth in **Section
      1.2(b)** .





Page
          12 of
          65








**PURCHASE
      AND SALE AGREEMENT**







This
      Agreement is executed on April 13, 2007, by and among Anadarko E&P Company
      LP **,** a
      Delaware limited partnership (“AEPC”), Kerr-McGee Oil & Gas Onshore LP, a
      Delaware limited partnership (“KMOG”; AEPC and KMOG collectively called
“Seller”), and EnerVest Energy Institutional Fund X-A, L.P., a Delaware limited
      partnership (“EnerVest X-A”), EnerVest Energy Institutional Fund X-WI, L.P., a
      Delaware limited partnership (“EnerVest X-WI”), EnerVest Energy Institutional
      Fund XI-A, L.P., a Delaware limited partnership (“EnerVest XI-A”), EnerVest
      Energy Institutional Fund XI-WI, L.P., a Delaware limited partnership (“EnerVest
      XI-WI”), EnerVest Management Partners, Ltd., a Texas limited partnership
      (“EnerVest”), Wachovia Investment Holdings, LLC, a Delaware limited liability
      company (“Wachovia”) and EV Properties, L.P., a Delaware limited partnership
      (“EV Properties”); EnerVest X-A, EnerVest X-WI, EnerVest XI-A, EnerVest XI-WI,
      EnerVest,Wachovia and EV Properties collectively called
“Purchaser”).




**RECITALS** ****




A.
      Seller
      owns various oil and gas properties, either of record or beneficially, more
      fully described in the exhibits hereto.




B.
      Seller
      desires to sell to Purchaser and Purchaser desires to purchase from Seller
      the
      properties and rights of Seller hereafter described, in the manner and upon
      the
      terms and conditions hereafter set forth.




C.
      Capitalized terms used herein shall have the meanings ascribed to them in this
      Agreement as such terms are identified and/or defined in the preceding
      Definitions section hereof.




NOW,
      THEREFORE, in consideration of the premises and of the mutual promises,
      representations, warranties, covenants, conditions and agreements contained
      herein, and for other valuable consideration, the receipt and sufficiency of
      which are hereby acknowledged, the parties hereto, intending to be legally
      bound
      by the terms hereof, agree as follows:







**ARTICLE
      1**


**PURCHASE
      AND SALE**




**Section
      1.1**  **Purchase
      and Sale** .




At
      the
      Closing, and upon the terms and subject to the conditions of this Agreement,
      Seller agrees to sell, transfer and convey the Assets to each Purchaser in
      the
      respective undivided interests set forth in **Schedule
      1.1** (each
      Purchaser’s undivided interest in the Assets called such Purchaser’s “Purchaser
      Share”) and each Purchaser agrees to purchase, accept and pay for such
      Purchaser’s Purchaser Share of the Assets and to assume the obligations
      attributable to such Purchaser’s Purchaser Share of the Assets.




Page
          13 of
          65




**Section
      1.2**  **Assets** **.**




As
      used
      herein, the term “Assets” means, subject to the terms and conditions of this
      Agreement, all of Seller’s right, title, interest and estate, real or personal,
      recorded or unrecorded, movable or immovable, tangible or intangible, in and
      to
      the following (but excluding the Excluded Assets):




(a)  All
      of
      the oil and gas leases; subleases and other leaseholds; carried interests;
      farmout rights; options; and other properties and interests described on **Exhibit
      A** ,
      subject
      to such depth limitations and other restrictions as may be set forth on **Exhibit
      A** (collectively,
      the “Leases”), together with each and every kind and character of right, title,
      claim, and interest that Seller has in and to the Leases or the lands currently
      pooled, unitized, communitized or consolidated therewith (the
“Lands”);




(b)  All
      oil,
      gas, water or injection wells located on the Lands, whether producing, shut-in,
      or temporarily abandoned, including the interests in the wells shown on **Exhibit
      A-1** attached
      hereto (the “Wells”);





(c)  All
      leasehold interest of Seller in or to any currently existing pools or units
      which include any Lands or all or a part of any Leases or include any Wells,
      including those pools or units shown on **Exhibit
      A-1** (the
      “Units”; the Units, together with the Leases, Lands and Wells, being hereinafter
      referred to as the “Properties”), and including all leasehold interest of Seller
      in production of Hydrocarbons from any such Unit, whether such Unit production
      of Hydrocarbons comes from Wells located on or off of a Lease, and all
      tenements, hereditaments and appurtenances belonging to the Leases and
      Units;




(d)  All
      contracts, agreements and instruments by which the Properties are bound, or
      that
      relate to or are otherwise applicable to the Properties, only to the extent
      applicable to the Properties rather than Seller’s other properties, including
      but not limited to, operating agreements, unitization, pooling and
      communitization agreements, declarations and orders, joint venture agreements,
      farmin and farmout agreements, exploration agreements, participation agreements,
      exchange agreements, transportation or gathering agreements, agreements for
      the
      sale and purchase of oil, gas, casinghead gas or processing agreements to the
      extent applicable to the Properties or the production of Hydrocarbons produced
      in association therewith from the Properties, including those identified on **Schedule
      1.2(d)** (hereinafter collectively referred to as “Contracts”), but excluding any
      contracts, agreements and instruments to the extent transfer is restricted
      by
      third-party agreement or applicable Law and the necessary consents to transfer
      are not obtained pursuant to **Section
      7.8** and
      provided that “Contracts” shall not include the instruments constituting the
      Leases;




(e)  All
      easements, permits, licenses, servitudes, rights-of-way, surface leases and
      other surface rights (“Surface Contracts”) appurtenant to, and used or held for
      use primarily in connection with the Properties (including those identified
      on **Schedule
      1.2(e)** ),
      but
      excluding any permits and other rights to the extent transfer is restricted
      by
      third-party agreement or applicable Law and the necessary consents to transfer
      are not obtained pursuant to **Section
      7.8** ;




(f)  All
      equipment, machinery, fixtures and other tangible personal property and
      improvements located on the Properties or used or held for use primarily in
      connection with the operation of the Properties, including those identified
      on **Exhibit A-2** (“Equipment”);




Page
          14 of
          65





(g)  All
      flow
      lines, pipelines, gathering systems and appurtenances thereto located on the
      Properties or used, or held for use, primarily in connection with the operation
      of the Properties, including those identified on **Schedule
      1.2(g)** (“Pipelines”);




(h)  All
      Hydrocarbons produced from or attributable to the Leases, Lands, and Wells
      from
      and after the Effective Time, together with Imbalances associated with the
      Properties;




(i)  All
      lease
      files; land files; well files; gas and oil sales contract files; gas processing
      files; division order files; abstracts; title opinions; land surveys;
      non-confidential logs; maps; engineering data and reports; and other books,
      records, data, files, and accounting records, in each case to the extent related
      primarily to the Assets, or used or held for use primarily in connection with
      the maintenance or operation thereof, but excluding (i) any books, records,
      data, files, maps and accounting records to the extent disclosure or transfer
      is
      restricted by third-party agreement or applicable Law and the necessary consents
      to transfer are not obtained pursuant to **Section
      7.8** ,
      (ii)
      attorney-client privileged communications and work product of Seller’s legal
      counsel (other than title opinions), (iii) reserve studies and evaluations,
      and
      (iv) records relating to the negotiation and consummation of the sale of the
      Assets (subject to such exclusions, the “Records”); and





(j)  Any
      solely-owned proprietary seismic data related to the Properties and, to the
      extent disclosure or transfer is not restricted by third-party agreement or
      applicable Law, any jointly-owned proprietary seismic data related to the
      Properties (provided, Purchaser shall assume, discharge and be liable for any
      obligation owed by Seller under the terms of the agreement covering such
      jointly-owned seismic data in connection with the transfer
      thereof).





**Section
      1.3**  **Excluded
      Assets.**




Notwithstanding
      the foregoing, the Assets shall not include, and there is excepted, reserved
      and
      excluded from the purchase and sale contemplated hereby (collectively, the
      “Excluded Assets”):




(a)  all
      corporate, financial, income and franchise tax and legal records of Seller
      that
      relate to Seller’s business generally (whether or not relating to the Assets),
      and all books, records and files that relate to the Excluded Assets and those
      records retained by Seller pursuant to **Section
      1.2(i)** and
      copies of any other Records retained by Seller pursuant to **Section
      1.5** ;




(b)  all
      non-proprietary geological and geophysical data (including all non-proprietary
      seismic data, including reprocessed data) and, to the extent not expressly
      included in **Section
      1.2(i)** ,
      all
      logs, interpretive data, technical evaluations, technical outputs, reserve
      estimates and economic estimates;





(c)  all
      rights to any refund of Taxes or other costs or expenses borne by Seller or
      Seller’s predecessors in interest and title attributable to periods prior to the
      Effective Time;




(d)  Seller’s
      area-wide bonds, permits and licenses or other permits, licenses or
      authorizations used in the conduct of Seller’s business generally;





(e)  those
      items listed in **Schedule
      1.3(e)** ;




Page
          15 of
          65




(f)  all
      trade
      credits, account receivables, note receivables, take-or-pay amounts receivable,
      and other receivables attributable to the Assets with respect to any period
      of
      time prior to the Effective Time;




(g)  **[RESERVED]** ;




(h)  all
      right, title and interest of Seller in and to vehicles or vessels used in
      connection with the Assets;





(i)  all
      rights, titles, claims and interests of Seller or any Affiliate of Seller (i)
      to
      or under any policy or agreement of insurance or any insurance proceeds; except
      to the extent provided in **Section
      3.5** ,
      and
      (ii) to or under any bond or bond proceeds;





(j)  any
      patent, patent application, logo, service mark, copyright, trade name or
      trademark of or associated with Seller or any Affiliate of Seller or any
      business of Seller or of any Affiliate of Seller; and





(k)  a
      nonexclusive right to freely use any seismic data, logs, maps, engineering
      data
      and reports, reserve studies and evaluations, and other data and information
      being transferred as a part of the Assets; provided, however, that Seller shall
      not assign its right hereunder to any third party.





**Section
      1.4**  **Effective
      Time; Proration of Costs and Revenues.**




(a)  Subject
      to **Section 1.5** ,
      possession of the Assets shall be transferred from Seller to Purchaser at the
      Closing, but certain financial benefits and burdens of the Assets shall be
      transferred effective as of 7:00 A.M., local time, where the respective Assets
      are located, on April 1, 2007 (the “Effective Time”), as described
      below.




Page
          16 of
          65




(b)Purchaser
      shall be entitled to all Hydrocarbon production from or attributable to the
      Leases, Units and Wells at and after the Effective Time (and all products and
      proceeds attributable thereto), and to all other income, proceeds, receipts
      and
      credits earned with respect to the Assets at or after the Effective Time, and
      shall be responsible for (and entitled to any refunds with respect to) all
      Property Costs incurred at and after the Effective Time. Seller shall be
      entitled to all Hydrocarbon production from or attributable to Leases, Units
      and
      Wells prior to the Effective Time (and all products and proceeds attributable
      thereto), and to all other income, proceeds, receipts and credits earned with
      respect to the Assets prior to the Effective Time, and shall be responsible
      for
      (and entitled to any refunds with respect to) all Property Costs incurred prior
      to the Effective Time. “Earned” and "incurred”, as used in this Agreement, shall
      be interpreted in accordance with generally accepted accounting principles
      and
      Council of Petroleum Accountants Society (COPAS) standards. “Property Costs”
means all costs attributable to the ownership and operation of the Assets
      (including without limitation costs of insurance and ad valorem, property,
      severance, Hydrocarbon production and similar Taxes based upon or measured
      by
      the ownership or operation of the Assets or the production of Hydrocarbons
      therefrom, but excluding any other Taxes) and capital expenditures incurred
      in
      the ownership and operation of the Assets in the ordinary course of business
      and, where applicable, in accordance with the relevant operating or unit
      agreement, if any, and overhead costs charged to the Assets under the relevant
      operating agreement or unit agreement, if any, or, if none, the amounts shown
      under**Schedule
      1.4**shall be
      the overhead amounts deemed charged to the Assets, but excluding without
      limitation liabilities, losses, costs, and expenses attributable to (i) Claims
      for personal injury or death, property damage or violation of any Law,(ii) obligations to plug wells or dismantle, abandon and salvage
      facilities, (iii) obligations to remediate any contamination of groundwater,
      surface water, soil, Equipment or Pipelines under applicable Environmental
      Laws,
      (iv) obligations to furnish make-up gas according to the terms of applicable
      gas
      sales, gathering or transportation contracts, (v) gas balancing obligations
      and
      (vi) obligations to pay working interests, royalties, overriding royalties
      or
      other interests held in suspense, all of which are addressed in **Article
      11** .
      For
      purposes of this **Section
      1.4** ,
      determination of whether Property Costs are attributable to the period before
      or
      after the Effective Time shall be based on when services are rendered, when
      the
      goods are delivered, or when the work is performed. For clarification, the
      date
      an item or work is ordered is not the date of a pre-Effective Time transaction
      for settlement purposes, but rather the date on which the item ordered is
      delivered to the job site, or the date on which the work ordered is performed,
      shall be the relevant date. For purposes of allocating Hydrocarbon production
      (and accounts receivable with respect thereto), under this **Section
      1.4,** (i)
      liquid Hydrocarbons shall be deemed to be “from or attributable to” the Leases,
      Units and Wells when they pass through the pipeline connecting into the storage
      facilities into which they are run and (ii) gaseous Hydrocarbons shall be deemed
      to be “from or attributable to” the Leases, Units and Wells when they pass
      through the delivery point sales meters on the pipelines through which they
      are
      transported. Seller shall utilize reasonable interpolative procedures to arrive
      at an allocation of Hydrocarbon production when exact meter readings or gauging
      and strapping data is not available. Seller shall provide to Purchaser, no
      later
      than five (5) Business Days prior to Closing, all data necessary to support
      any
      estimated allocation, for purposes of establishing the adjustment to the
      Purchase Price pursuant to **Section
      2.2** hereof
      that will be used to determine the Closing Payment (as defined in **Section
      9.4(a)** ).
      Taxes,
      right-of-way fees, insurance premiums and other Property Costs that are paid
      periodically shall be prorated based on the number of days in the applicable
      period falling before and the number of days in the applicable period falling
      at
      or after the Effective Time, except that Hydrocarbon production, severance
      and
      similar Taxes shall be prorated based on the number of units actually produced,
      purchased or sold or proceeds of sale, as applicable, before, and at or after,
      the Effective Time. In each case, Purchaser shall be responsible for the portion
      allocated to the period at and after the Effective Time and Seller shall be
      responsible for the portion allocated to the period before the Effective
      Time.




**Section
      1.5**  **Delivery
      and Maintenance of Records** .





(a)  Seller,
      at Purchaser’s cost, shall use reasonable efforts to deliver the Records (FOB
      Seller's office) to Purchaser as soon as possible (but in no event later than
      thirty (30) days) following Closing. Seller may retain copies of any Records
      at
      Seller’s expense.





(b)  Purchaser,
      for a period of seven (7) years following Closing, will (i) retain the Records,
      (ii) provide Seller, its Affiliates, and its and their officers, employees
      and
      representatives with access to the Records during normal business hours for
      review and copying at Seller’s expense, and (iii) provide Seller, its
      Affiliates, and its and their officers, employees and representatives with
      access, during normal business hours, to materials received or produced after
      Closing relating to any Indemnity Claim made under **Section
      11.4** of this
      Agreement for review and copying at Seller’s expense.




Page
          17 of
          65




**ARTICLE
      2**


**PURCHASE
      PRICE**




**Section
      2.1**  **Purchase
      Price** .




The
      purchase price for the Assets (the “Purchase Price”) shall be Seven Hundred
      Fifty Million Dollars ($750,000,000.00 U.S.D.) adjusted as provided in **Section
      2.2** .




**Section
      2.2**  **Adjustments
      to Purchase Price** **.**




The
      Purchase Price for the Assets shall be adjusted as follows with all such amounts
      being determined in accordance with generally accepted accounting principles
      and
      Council of Petroleum Accountants Society (COPAS) standards:




(a)  Reduced
      by the aggregate amount of the following proceeds received by Seller between
      the
      Effective Time and the Closing Date (with the period between the Effective
      Time
      and the Closing Date referred to as the “Adjustment Period”): (i) proceeds from
      the sale of Hydrocarbons (net of any royalties, overriding royalties or other
      burdens on or payable out of Hydrocarbon production, gathering, processing
      and
      transportation costs and any Hydrocarbon production, severance, sales or excise
      Taxes not reimbursed to Seller by the purchaser of Hydrocarbon production)
      produced from or attributable to the Properties during the Adjustment Period,
      and (ii) other proceeds earned with respect to the Assets during the Adjustment
      Period;




(b)  Reduced
      to the extent provided in **Section 7.8** with
      respect to Preference Rights and Retained Assets;





(c)  (i)
      If
      Seller makes the election under **Section 3.4(d)(i)** with
      respect to a Title Defect, subject to the Individual Title Deductible and the
      Aggregate Deductible, reduced by the Title Defect Amount with respect to such
      Title Defect if the Title Defect Amount has been determined prior to Closing
      and
      (ii) subject to the Individual Benefit Deductible and the Aggregate Benefit
      Deductible, increased by the Title Benefit Amount with respect to each Title
      Benefit for which the Title Benefit Amount has been determined prior to
      Closing;




(d)  Increased
      by the amount of all Property Costs and other costs attributable to the
      ownership and operation of the Assets which are paid by Seller and incurred
      at
      or after the Effective Time (including any overhead costs under **Schedule
      1.4** deemed
      charged to the Assets with respect to the Adjustment Period even though not
      actually paid), except any Property Costs and other such costs already deducted
      in the determination of proceeds in **Section
      2.2(a)** ;




(e)  If
      Seller
      makes the election under **Section
      4.3(c)(i)** with
      respect to an Environmental Defect, subject to the Individual Environmental
      Deductible and Aggregate Deductible, reduced by the Environmental Defect Amount
      with respect to such Environmental Defect if the Environmental Defect Amount
      has
      been determined prior to Closing;





(f)  Increased
      or reduced as agreed upon in writing by Seller and Purchaser;





(g)  Increased
      by the amount of merchantable Hydrocarbons stored in tanks and pipelines
      attributable to the ownership and operation of the Assets that belong to Seller
      as of the Effective Time; and




Page
          18 of
          65





(h)  Reduced
      by the aggregate amounts payable to owners of working interests, royalty
      interests, or other interests in the Properties held in suspense by Seller
      as of
      the Closing Date, as reflected on the schedule to be delivered by Seller to
      Purchaser pursuant to **Section
      9.2(g)** which
      amount shall be net of all amounts that, as of the Effective Time, should be
      escheated to the State pursuant to applicable regulations.




Each
      adjustment made pursuant to **Section
      2.2(a)** shall
      serve to satisfy, up to the amount of the adjustment, Purchaser’s entitlement
      under **Section
      1.4** to
      Hydrocarbon production from or attributable to the Properties during the
      Adjustment Period, and to the value of other income, proceeds, receipts and
      credits earned with respect to the Assets during the Adjustment Period, and
      as
      such, Purchaser shall not have any separate rights to receive any Hydrocarbon
      production or income, proceeds, receipts and credits with respect to which
      an
      adjustment has been made. Similarly, the adjustment described in **Section
      2.2(d)** shall
      serve to satisfy, up to the amount of the adjustment, Purchaser’s obligation
      under **Section
      1.4** to pay
      Property Costs and other costs attributable to the ownership and operation
      of
      the Assets which are incurred during the Adjustment Period, and as such,
      Purchaser shall not be separately obligated to pay for any Property Costs or
      other such costs with respect to which an adjustment has been made.




The
      Purchase Price less the Deposit provided in **Section
      2.4** ,
      adjusted as set forth in (a) through (h), shall be increased by simple interest
      thereon from the Effective Time to the Closing Date, computed at the Agreed
      Interest Rate.





**Section
      2.3**  **Allocation
      of Purchase Price for Tax Purposes** .




Concurrent
      with the execution of this Agreement, Purchaser and Seller will agree upon
      an
      allocation of the unadjusted Purchase Price among the Assets, in compliance
      with
      the principles of Section 1060 of the Internal Revenue Code of 1986, as amended
      (the “Code”), and the Treasury regulations thereunder. Such allocation of value
      shall be attached to this Agreement as **Schedule
      2.3** and
      shall
      be treated as Class V assets for purposes of Internal Revenue Service Form
      8594.
      The “Tax Allocated Value” for any Asset equals the portion of the unadjusted
      Purchase Price allocated to such Asset on **Schedule
      2.3** ,
      increased or reduced as described in this **Article
      2** .
      Any
      adjustments to the Purchase Price other than the adjustments provided for in **Sections
      2.2(b)** and **2.2(c)** shall be
      applied on a pro rata basis to the amounts set forth on **Schedule
      2.3** for all
      Assets. After all such adjustments are made, any adjustments to the Purchase
      Price pursuant to **Sections
      2.2(b)** and **2.2(c)** shall be
      applied to the amounts set forth in **Schedule
      2.3** for the
      particular affected Assets. After Seller and Purchaser have agreed on the Tax
      Allocated Values for the Assets, Seller will be deemed to have accepted such
      Tax
      Allocated Values for purposes of this Agreement and the transactions
      contemplated hereby, but otherwise makes no representation or warranty as to
      the
      accuracy of such values. Seller and Purchaser agree (i) that the Tax Allocated
      Values shall be used by Seller and Purchaser as the basis for reporting asset
      values and other items for purposes of all federal, state, and local Tax
      Returns, including without limitation Internal Revenue Service Form 8594 and
      (ii) that neither they nor their Affiliates will take positions inconsistent
      with the Tax Allocated Values in notices to government authorities or in audit
      or other proceedings with respect to Taxes. Purchaser and Seller further agree
      that the portion of Tax Allocated Values included in **Schedule
      2.3** attributable to tangible personal property shall equal the Seller’s tax basis in
      such property on the Closing Date.




Page
          19 of
          65





**Section
      2.4**  **Deposit** .





Concurrently
      with the execution of this Agreement, Purchaser shall pay to Seller an earnest
      money deposit in an amount equal to five percent (5%) of the Purchase Price
      (the
      "Deposit"). The Deposit shall bear interest from the date of payment to Seller
      to the Closing Date, computed at the Agreed Interest Rate, and the Deposit,
      together with such interest, shall be applied against the Purchase Price if
      the
      Closing occurs or shall be otherwise distributed in accordance with the terms
      of
      this Agreement.




**ARTICLE
      3**


**TITLE
      MATTERS**




**Section
      3.1**  **Seller’s
      Title** .




(a)  Except
      for the special warranty of title referenced in **Section
      3.1(b)** and
      without limiting Purchaser’s right to adjust the Purchase Price by operation of
      this **Article
      3** ,
      Seller
      makes no warranty or representation, express, implied, statutory or otherwise,
      with respect to Seller’s title to any of the Assets and Purchaser hereby
      acknowledges and agrees that Purchaser’s sole remedy for any defect of title,
      including any Title Defect, with respect to any of the Assets (i) before
      Closing, shall be Purchaser’s right to adjust the Purchase Price to the extent
      provided in this **Article
      3** and (ii)
      after Closing, shall be pursuant to the special warranty of title referenced
      in **Section
      3.1(b)** .




(b)  The
      conveyance to be delivered by Seller to Purchaser shall be substantially in
      the
      form of **Exhibit
      B** hereto
      (the “Conveyance”) and contain a special warranty of Defensible Title by,
      through and under Seller but not otherwise to the Units and Wells shown on **Exhibit
      A-1** ,
      subject
      to the Permitted Encumbrances, but shall otherwise be without warranty of title
      of any kind, express, implied or statutory or otherwise.




(c)  Purchaser
      shall not be entitled to protection under Seller’s special warranty of title in
      the Conveyance against any Title Defect reported under this **Article
      3** and/or
      any Title Defect disclosed to or known by Purchaser prior to the Title Claim
      Date.





(d)  Notwithstanding
      anything herein provided to the contrary, if a Title Defect under this **Article
      3** results
      from any matter which could also result in the breach of any representation
      or
      warranty of Seller set forth in **Article
      5** ,
      then
      Purchaser shall only be entitled to assert such matter (i) before Closing,
      as a
      Title Defect to the extent permitted by this **Article
      3** ,
      or (ii)
      after Closing, as a breach of Seller’s special warranty of title contained in
      the Conveyance to the extent permitted by this **Section
      3.1** ,
      and
      shall be precluded from also asserting such matter as the basis of the breach
      of
      any such representation or warranty.





**Section
      3.2**  **Definition
      of Defensible Title** .




As
      used
      in this Agreement, the term “Defensible Title” means that title of Seller with
      respect to the Units or Wells shown in **Exhibit
      A-1** that,
      except for and subject to Permitted Encumbrances:




(a)  Entitles
      Seller to receive a share of the Hydrocarbons produced, saved and marketed
      from
      any Unit or Well shown in **Exhibit
      A-1** throughout the duration of the productive life of such Unit or Well (after
      satisfaction of all royalties, overriding royalties, net profits interests
      or
      other similar burdens on or measured by production of Hydrocarbons) (a “Net
      Revenue Interest”), of not less than the Net Revenue Interest shown in **Exhibit
      A-1**for such
      Unit or Well, except decreases in connection with those operations in which
      Seller may after the Effective Time be a non-consenting co-owner, decreases
      resulting from the establishment or amendment after the Effective Time of pools
      or units, and decreases required to allow other working interest owners to
      make
      up past underproduction or pipelines to make up past under deliveries, and
      except as stated in such**Exhibit
      A-1**;




Page
          20 of
          65




(b)  Obligates
      Seller to bear a percentage of the costs and expenses for the maintenance and
      development of, and operations relating to, (i) any Unit or Well shown in **Exhibit
      A-1** not
      greater than the “working interest” shown in **Exhibit
      A-1** for such
      Unit or Well without increase throughout the productive life of such Unit or
      Well, except as stated in **Exhibit
      A-1** and
      except increases resulting from contribution requirements with respect to
      non-consenting co-owners under applicable operating agreements and increases
      that are accompanied by at least a proportionate increase in Seller’s Net
      Revenue Interest; and




(c)  Is
      free
      and clear of liens, encumbrances, obligations, security interests,
      irregularities, pledges, or other defects.





As
      used
      in this Agreement, the term “Title Defect” means any lien, charge, encumbrance,
      obligation (including contract obligation), defect, or other matter (including
      without limitation a discrepancy in Net Revenue Interest or working interest)
      that causes Seller not to have Defensible Title in and to the Units and Wells
      shown in **Exhibit A-1** as of
      the Effective Time. As used in this Agreement, the term “Title Benefit” shall
      mean any right, circumstance or condition that operates to increase the Net
      Revenue Interest of Seller in any Unit or Well shown on **Exhibit
      A-1** ,
      without
      causing a greater than proportionate increase in Seller’s working interest above
      that shown in **Exhibit
      A-1** as of
      the Effective Time. Notwithstanding the foregoing, the following shall not
      be
      considered Title Defects:





1.
            defects
                based solely on (i) lack of information in the Seller’s files, or (ii)
                references to a document(s) solely because such document(s) is not
                in
                Seller’s files;





2.
            defects
                in the chain of title prior to January 1,
                1950;





3.
            defects
                arising out of lack of corporate or other entity authorization unless
                Purchaser provides affirmative evidence that the action was not authorized
                and results in another party’s superior claim of title to the relevant
                Property;





4.
            defects
                based on failure to record Leases issued by any state, federal or
                other
                Governmental Body, or any assignments of record title or operating
                rights
                in such Leases, in the real property, conveyance or other records
                of the
                county in which such Property is located; provided, however, such
                defect
                has not resulted in another party’s superior claim of title to the
                relevant Property;





5.
            defects
                based on a gap in Seller’s chain of title in the county records as to fee
                Leases, unless such gap is affirmatively shown to exist in such records
                by
                an abstract of title, title opinion or landman’s title chain which
                documents shall be included in a Title Defect Notice;





6.
            defects
                that have been cured by applicable Laws of limitations or
                prescription;




Page
          21 of
          65




7.
            any
                delay in delivering an assignment earned under a farmout, participation
                or
                similar agreement unless Purchaser provides affirmative evidence
                that the
                farmor or other third party record title holder has refused to deliver
                such assignment; and





8.
            defects
                disclosed to or known by Purchaser and/or its Affiliates prior to
                the
                execution of this Agreement.





**Section
      3.3**  **Definition
      of Permitted Encumbrances** .




As
      used
      herein, the term “Permitted Encumbrances” means any or all of the
      following:




(a)  Royalties
      and any overriding royalties, reversionary interests and other burdens to the
      extent that the net cumulative effect of such burdens does not materially reduce
      Seller’s Net Revenue Interest below that shown in **Exhibit
      A-1** or
      materially increase Seller’s working interest above that shown in **Exhibit
      A-1** without
      a corresponding increase in the Net Revenue Interest;




(b)  All
      Leases, unit agreements, pooling agreements, operating agreements, Hydrocarbon
      production sales contracts, division orders and other contracts, agreements
      and
      instruments applicable to the Assets, to the extent that the net cumulative
      effect of such instruments does not materially reduce Seller’s Net Revenue
      Interest below that shown in **Exhibit
      A-1** or
      materially increase Seller’s working interest above that shown in **Exhibit
      A-1** without
      a corresponding increase in the Net Revenue Interest;




(c)  Preference
      Rights applicable to the Assets;




(d)  Third-party
      consent requirements and similar restrictions;




(e)  Liens
      for
      current Taxes or assessments not yet delinquent or, if delinquent, being
      contested in good faith by appropriate actions;





(f)  Materialman’s,
      mechanic’s, repairman’s, employee’s, contractor’s, operator’s and other similar
      liens or charges arising in the ordinary course of business for amounts not
      yet
      delinquent (including any amounts being withheld as provided by Law), or if
      delinquent, being contested in good faith by appropriate actions;




(g)  All
      rights to consent by, required notices to, filings with, or other actions by
      Governmental Bodies in connection with the sale or conveyance of the Assets
      or
      interests therein if they are not required or customarily obtained prior to
      the
      sale or conveyance;




(h)  Rights
      of
      reassignment arising upon final intention to abandon or release the Assets,
      or
      any of them;




(i)  Easements,
      rights-of-way, servitudes, permits, surface leases and other rights in respect
      of surface operations to the extent that they do not individually reduce
      Seller’s Net Revenue Interest below that shown in **Exhibit
      A-1** or
      increase Seller’s working interest above that shown in **Exhibit
      A-1** without
      a corresponding increase in Net Revenue Interest or unreasonably restrict or
      interfere with the use and operation of the affected assets;




Page
          22 of
          65




(j)  Calls
      on
      Hydrocarbon production under existing Contracts that are listed on **Schedule
      5.11** or that
      reflect market pricing;




(k)  All
      rights reserved to or vested in any Governmental Body to control or regulate
      any
      of the Assets in any manner and all obligations and duties under all applicable
      laws, rules and orders of any such Governmental Body or under any franchise,
      grant, license or permit issued by any such Governmental Body;




(l)  Any
      encumbrance on or affecting the Assets which is expressly assumed, bonded or
      paid by Purchaser at or prior to Closing or which is discharged by Seller at
      or
      prior to Closing;




(m)  Any
      matters shown on **Exhibit
      A-1** ;




(n)  Any
      other
      liens, charges, encumbrances, defects or irregularities which do not,
      individually or in the aggregate, materially interfere with the use or ownership
      of the Assets subject thereto or affected thereby (as currently used or owned),
      which would be accepted by a reasonably prudent purchaser engaged in the
      business of owning and operating oil and gas properties, and which do not reduce
      Seller’s Net Revenue Interest below that shown in **Exhibit
      A-1** ,
      or
      increase Seller’s working interest above that shown in **Exhibit
      A-1** without
      a corresponding increase in Net Revenue Interest;




(o)  Matters
      that would otherwise be considered Title Defects but that do not meet the
      Individual Title Deductible set forth in **Section
      3.4(j)** ;





(p)  Imbalances
      associated with the Assets; and





(q)  Liens
      granted under applicable joint operating agreements provided same have not
      been
      perfected with respect to actual unpaid amounts.





**Section
      3.4**  **Notice
      of Title Defect Adjustments** .




(a)  To
      assert
      a claim of a Title Defect, Purchaser must deliver claim notices to Seller (each
      a “Title Defect Notice”) on or before June 6, 2007 (the “Title Claim Date”);
      provided, however, that Purchaser agrees that it shall furnish Seller once
      every
      two (2) weeks from and after the date hereof until the Title Claim Date with
      Title Defect Notices with respect to any Title Defects that Purchaser’s or any
      of its Affiliate’s employees or representatives discover or learn of during such
      two (2) week period. Each Title Defect Notice shall be in writing and shall
      include (i) a description of the alleged Title Defect(s), (ii) the Units or
      Wells affected by the Title Defect (each a “Title Defect Property”), (iii) the
      Allocated Value of each Title Defect Property, (iv) supporting documents
      reasonably necessary for Seller (as well as any title attorney or examiner
      hired
      by Seller) to verify the existence of the alleged Title Defect(s), and (v)
      the
      amount by which Purchaser reasonably believes the Allocated Value of each Title
      Defect Property is reduced by the alleged Title Defect(s) and the computations
      and information upon which Purchaser’s belief is based. Notwithstanding any
      other provision of this Agreement to the contrary, Purchaser shall be deemed
      to
      have waived its right to assert Title Defects that Seller has not been given
      notice on or before the Title Claim Date. For purposes of this Agreement, the
      term “Allocated Value” shall mean the portion of the Purchase Price that has
      been allocated to a Unit or Well in **Exhibit
      A-1** .




Page
          23 of
          65




(b)  Seller
      shall have the right, but not the obligation, to deliver to Purchaser on or
      before the Title Claim Date with respect to each Title Benefit a notice (a
      “Title Benefit Notice”) including (i) a description of the Title Benefit, (ii)
      the Units or Wells affected, (iii) the Allocated Values of the Units or Wells
      subject to such Title Benefit and (iv) the amount by which the Seller reasonably
      believes the Allocated Value of those Units or Wells is increased by the Title
      Benefit, and the computations and information upon which Seller’s belief is
      based. Seller shall be deemed to have waived all Title Benefits of which it
      has
      not given notice on or before the Title Claim Date.




(c)  Seller
      shall have the right, but not the obligation, to attempt, at its sole cost,
      to
      cure or remove at any time prior to Closing (the “Cure Period”), unless the
      parties otherwise agree, any Title Defects of which it has been advised by
      Purchaser.




(d)  *Remedies
      for Title Defects.*





In
      the
      event that any Title Defect is not waived by Purchaser or cured on or before
      Closing, Seller shall, at its sole election, elect to:





(i)  subject
      to the Individual Title Deductible and the Aggregate Deductible, reduce the
      Purchase Price by an amount agreed upon ("Title Defect Amount") pursuant to **Section
      3.4(g)** or **3.4(i)** by
      Purchaser and Seller as being the value of such Title Defect, taking into
      consideration the Allocated Value of the Property subject to such Title Defect,
      the portion of the Property subject to such Title Defect and the legal effect
      of
      such Title Defect on the Property affected thereby; *provided,
      however* ,
      that
      the methodology, terms and conditions of **Section
      3.4(g)** shall
      control any such determination;





(ii)  indemnify
      Purchaser against all liability, loss, cost and expense resulting from such
      Title Defect pursuant to an indemnity agreement (the "Indemnity Agreement")
      in
      the form attached hereto as **Exhibit C** ;
      or





(iii)  if
      applicable, terminate this Agreement on account of the condition set forth
      in **Section 8.1(e)** not
      being satisfied.





(e)  With
      respect to each Unit or Well affected by Title Benefits reported under **Section
      3.4(b)** ,
      the
      Purchase Price shall be increased by an amount (the “Title Benefit Amount”)
      equal to the increase in the Allocated Value for such Unit or Well caused by
      such Title Benefits, as determined pursuant to **Section
      3.4(h)** .




(f)  **Section
      3.4(d)** shall be
      the exclusive right and remedy of Purchaser with respect to Title Defects
      asserted by Purchaser pursuant to **Section
      3.4** .




(g)  The
      Title
      Defect Amount resulting from a Title Defect shall be the amount by which the
      Allocated Value of the Title Defect Property affected by such Title Defect
      is
      reduced as a result of the existence of such Title Defect and shall be
      determined in accordance with the following methodology, terms and
      conditions:




(i)  if
      Purchaser and Seller agree on the Title Defect Amount, that amount shall be
      the
      Title Defect Amount;




Page
          24 of
          65




(ii)  if
      the
      Title Defect is a lien, encumbrance or other charge which is undisputed and
      liquidated in amount, then the Title Defect Amount shall be the amount necessary
      to be paid to remove the Title Defect from the Title Defect
      Property;




(iii)  if
      the
      Title Defect represents a discrepancy between (A) the Net Revenue Interest
      for
      any Title Defect Property and (B) the Net Revenue Interest stated on **Exhibit
      A-1** ,
      then
      the Title Defect Amount shall be the product of the Allocated Value of such
      Title Defect Property multiplied by a fraction, the numerator of which is the
      Net Revenue Interest decrease and the denominator of which is the Net Revenue
      Interest stated on **Exhibit
      A-1** ;




(iv)  if
      the
      Title Defect represents an obligation, encumbrance, burden or charge upon or
      other defect in title to the Title Defect Property of a type not described
      in
      subsections (i), (ii) or (iii) above, the Title Defect Amount shall be
      determined by taking into account the Allocated Value of the Title Defect
      Property, the portion of the Title Defect Property affected by the Title Defect,
      the legal effect of the Title Defect, the potential economic effect of the
      Title
      Defect over the life of the Title Defect Property, the values placed upon the
      Title Defect by Purchaser and Seller and such other factors as are necessary
      to
      make a proper evaluation; and




(v)  notwithstanding
      anything to the contrary in this **Article
      3** ,
      the
      aggregate Title Defect Amounts attributable to the effects of all Title Defects
      upon any Title Defect Property shall not exceed the Allocated Value of the
      Title
      Defect Property.




(h)  The
      Title
      Benefit Amount for any Title Benefit shall be the product of the Allocated
      Value
      of the affected Unit or Well multiplied by a fraction, the numerator of which
      is
      the Net Revenue Interest increase and the denominator of which is the Net
      Revenue Interest stated on **Exhibit
      A-1** .




(i)  Seller
      and Purchaser shall attempt to agree on all Title Defect Amounts and Title
      Benefit Amounts prior to Closing. If Seller and Purchaser are unable to agree
      by
      Closing, the Title Defect Amounts and Title Benefit Amounts in dispute shall
      be
      exclusively and finally resolved by arbitration pursuant to this **Section
      3.4(i)** .
      There
      shall be a single arbitrator, who shall be a title attorney with at least ten
      (10) years experience in oil and gas titles involving properties in the regional
      area in which the Properties are located, as selected by mutual agreement of
      Purchaser and Seller within fifteen (15) Business Days after the end of the
      Cure
      Period, and absent such agreement, by the Houston office of the American
      Arbitration Association (the “Title Arbitrator”). The arbitration proceeding
      shall be held in Houston, Texas and shall be conducted in accordance with the
      Commercial Arbitration Rules of the American Arbitration Association, to the
      extent such rules do not conflict with the terms of this Section. The Title
      Arbitrator’s determination shall be made within fifteen (15) Business Days after
      submission of the matters in dispute and shall be final and binding upon both
      parties, without right of appeal. In making his determination, the Title
      Arbitrator shall be bound by the rules set forth in **Sections
      3.4(g)** and **3.4(h)** and may
      consider such other matters as in the opinion of the Title Arbitrator are
      necessary or helpful to make a proper determination. Additionally, the Title
      Arbitrator may consult with and engage disinterested third parties to advise
      the
      arbitrator, including without limitation petroleum engineers. The Title
      Arbitrator shall act as an expert for the limited purpose of determining the
      specific disputed Title Defect Amounts and Title Benefit Amounts submitted
      by
      either party and may not award damages, interest or penalties to either party
      with respect to any matter. Seller and Purchaser shall each bear its own legal
      fees and other costs of presenting its case. Each party shall bear one-half
      of
      the costs and expenses of the Title Arbitrator, including any costs incurred
      by
      the Title Arbitrator that are attributable to such third party consultation.
      Within ten (10) days after the Title Arbitrator delivers written notice to
      Purchaser and Seller of his award with respect to a Title Defect Amount or
      a
      Title Benefit Amount, (i) Purchaser shall pay to Seller the amount, if any,
      so
      awarded by the Title Arbitrator to Seller and (ii) Seller shall pay to Purchaser
      the amount, if any, so awarded by the Title Arbitrator to
      Purchaser.




Page
          25 of
          65




(j)  Notwithstanding
      anything to the contrary, (i) in no event shall there be any adjustments to
      the Purchase Price or other remedies provided by Seller for individual Title
      Defects that do not exceed $100,000.00 (“Individual Title Deductible”); and
      (ii) in no event shall there be any adjustments to the Purchase Price or
      other remedies provided by Seller for Title Defects unless the amount of all
      such Title Defects, in the aggregate, excluding any Title Defects cured by
      Seller, taken together with the aggregate Environmental Defect Amounts, exceeds
      a deductible in an amount equal to three percent (3%) of the Purchase Price
      (“Aggregate Deductible”), after which point Purchaser shall be entitled to
      adjustments to the Purchase Price or other remedies only with respect to Title
      Defects in excess of such Aggregate Deductible. Notwithstanding anything to
      the
      contrary contained herein, in no event shall there be any adjustments to the
      Purchase Price for (x) any individual Title Benefit that does not exceed
      $100,000.00 (the “Individual Benefit Deductible”) and (y) for any Title Benefit
      unless the amount of all such Title Benefits, in the aggregate, exceeds a
      deductible in the amount equal to three percent (3%) of the Purchase Price
      (“Aggregate Benefit Deductible”), after which point Seller shall be entitled to
      adjustments to the Purchase Price only with respect to Title Benefits in excess
      of such Aggregate Benefit Deductible.




**Section
      3.5**  **Casualty
      or Condemnation Loss** .




(a)  Purchaser
      shall assume all risk of loss with respect to, and any change in the condition
      of the Assets from the Effective Time until Closing for production of
      Hydrocarbons through normal depletion (including but not limited to the watering
      out of any Well, collapsed casing or sand infiltration of any Well) and the
      depreciation of personal property due to ordinary wear and tear.





(b)  Subject
      to the provisions of **Sections
      8.1(f)** and **8.2(f)** hereof,
      if, after the date of this Agreement but prior to the Closing Date, any portion
      of the Assets is destroyed by fire or other casualty or is taken in condemnation
      or under right of eminent domain, and the loss as a result of such individual
      casualty or taking exceeds ten percent (10%) of the Purchase Price, Purchaser
      shall nevertheless be required to close and Seller shall elect by written notice
      to Purchaser prior to Closing either (i) to cause the Assets affected by any
      casualty or taking to be repaired or restored to at least its condition prior
      to
      such casualty, at Seller’s sole cost, as promptly as reasonably practicable
      (which work may extend after the Closing Date), (ii) to indemnify Purchaser
      through a document reasonably acceptable to Seller and Purchaser against any
      costs or expenses that Purchaser reasonably incurs to repair the Assets subject
      to any casualty or taking or (iii) to treat such casualty or taking as a Title
      Defect with respect to the affected Property or Properties under **Section
      3.4** ;
      provided, however, the deductibles provided under **Section
      3.4(j)** shall
      not be applicable to any such casualty or taking treated as a Title Defect
      pursuant to this **Section
      3.5(b)(iii)** .
      In each
      case, Seller shall retain all rights to insurance and other claims against
      third
      parties with respect to the casualty or taking except to the extent the parties
      otherwise agree in writing.




Page
          26 of
          65




(c)  If,
      after
      the date of this Agreement but prior to the Closing Date, any portion of the
      Assets is destroyed by fire or other casualty or is taken in condemnation or
      under right of eminent domain, and the loss as a result of such individual
      casualty or taking is ten percent (10%) or less of the Purchase Price, Purchaser
      shall nevertheless be required to close and Seller shall, at Closing, pay to
      Purchaser all sums paid to Seller by third parties by reason of such casualty
      or
      taking and shall assign, transfer and set over to Purchaser or subrogate
      Purchaser to all of Seller’s right, title and interest (if any) in insurance
      claims, unpaid awards, and other rights against third parties (other than
      Affiliates of Seller and its and their directors, officers, employees and
      agents) arising out of the casualty or taking.




**Section
      3.6**  **Limitations
      on Applicability** .




The
      right
      of Purchaser to assert a Title Defect under this Agreement shall terminate
      as of
      the Title Claim Date, provided there shall be no termination of Purchaser’s or
      Seller’s rights under **Section
      3.4** with
      respect to any bona fide Title Defect properly reported in a Title Defect Notice
      or bona fide Title Benefit Claim properly reported in a Title Benefit Notice
      on
      or before the Title Claim Date. Thereafter, Purchaser’s sole and exclusive
      rights and remedies with regard to title to the Assets shall be as set forth
      in,
      and arise under, the Conveyance transferring the Assets from Seller to
      Purchaser.





**Section
      3.7**  **Government
      Approvals Respecting Assets**





(a)  Federal
      and State Approvals .
      Purchaser, within thirty (30) days after Closing, shall file for approval with
      the applicable government agencies all assignment documents and other state
      and
      federal transfer documents required to effectuate the transfer of the Assets.
      Purchaser further agrees promptly after Closing to take all other actions
      reasonably required of it by federal or state agencies having jurisdiction
      to
      obtain all requisite regulatory approvals with respect to this transaction,
      and
      to use its reasonable commercial efforts to obtain the approval by such federal
      or state agencies, as applicable, of Seller’s assignment documents requiring
      federal or state approval in order for Purchaser to be recognized by the federal
      or state agencies as the owner of the Assets. Purchaser shall provide Seller
      with the resignation and designation of operator instruments, and approved
      copies of the assignment documents and other state and federal transfer
      documents, as soon as they are available.





(b)  Title
      Pending Governmental Approvals .
      Until
      all of the governmental approvals provided for in **Section
      3.7(a)** have
      been obtained, the following shall occur with respect to the affected portion
      of
      the Assets:





(i)  Seller
      shall continue to hold record title to the affected Leases and other affected
      portion of the Assets as nominee for Purchaser;





(ii)  Purchaser
      shall be responsible for all assumed obligations with respect to the affected
      Leases and other affected portion of the Assets as if Purchaser was the record
      owner of such Leases and other portion of the Assets as of the Effective Date;
      and





(iii)  Seller
      shall act as Purchaser’s nominee but shall be authorized to act only upon and in
      accordance with Purchaser’s instructions, and Seller shall have no authority,
      responsibility or discretion to perform any tasks or functions with respect
      to
      the affected Leases and other affected portion of the Assets other than those
      which are purely administrative or ministerial in nature, unless otherwise
      specifically requested and authorized by Purchaser in writing.




Page
          27 of
          65




(c)  Denial
      of Required Governmental Approvals .
      If the
      federal or state agency fails to do so within twenty-four (24) months after
      the
      Closing, Seller may continue to hold record title to the affected Leases and
      other affected Assets as Purchaser’s nominee or at Seller’s option it may
      terminate this Agreement and all its obligations hereunder as to the affected
      Leases and other affected portion of the Assets by giving sixty (60) days
      written notice to Purchaser. Upon such termination: (i) this Agreement shall
      be
      null and void and terminated as to the affected Leases and other affected
      portion of the Assets, (ii) Purchaser shall immediately reassign and return
      to
      Seller the assignment documents and any and all other documents, materials
      and
      data previously delivered to Purchaser with respect to the affected Leases
      and
      other affected portion of the Assets, and (iii) Seller shall pay to Purchaser
      the Allocated Value of the affected Property, without interest, less the
      proceeds of Hydrocarbon production received by Purchaser (which shall be
      retained by Purchaser as its sole property) net of all expenses, overhead,
      royalties, and costs of operations (including plugging and abandonment expenses
      but excluding mortgage interest and any burdens, liens, or encumbrances created
      by Purchaser which must be released prior to this payment) attributable to
      the
      affected Leases or other affected portion of the Assets from the Effective
      Date
      forward. In no event, however, shall Seller ever be required to reimburse
      Purchaser for any expenditures associated with workovers, recompletions,
      sidetracks, or the drilling, completion or plugging and abandonment of wells
      drilled or work performed by Seller.





**ARTICLE
      4**


**ENVIRONMENTAL
      MATTERS**





**Section
      4.1**  **Assessment** **.**




Upon
      notice to Seller, Purchaser shall, subject to the provisions of **Section
      11.4(b)(iv)** ,
      have
      the right to conduct an environmental assessment of all or any portion of the
      Properties (the “Assessment”) to be conducted by a reputable environmental
      consulting or engineering firm approved in advance in writing by Seller but
      only
      to the extent that Seller may grant such right without violating any obligations
      to any third party. The Assessment shall be conducted at the sole cost and
      expense of Purchaser, and shall be subject to the indemnity provisions of **Section
      4.4** and **Section
      11.4(b)(vi)** .
      Prior
      to conducting any sampling, boring, drilling or other invasive investigative
      activity with respect to the Properties (“Invasive Activity”), Purchaser shall
      furnish for Seller’s review a proposed scope of such Invasive Activity,
      including a description of the activities to be conducted and a description
      of
      the approximate locations of such activities. If any of the proposed activities
      may unreasonably interfere with normal operation of the Properties, Seller
      may
      request an appropriate modification of the proposed Invasive Activity. Seller
      shall have the right to be present during any Assessment of the Properties
      and
      shall have the right, at its option and expense, to split samples with
      Purchaser. After completing any Assessment of the Properties, Purchaser shall,
      at its sole cost and expense, restore the Properties to their condition prior
      to
      the commencement of such Assessment, unless Seller requests otherwise, and
      shall
      promptly dispose of all drill cuttings, corings, or other investigative-derived
      wastes generated in the course of the Assessment. Purchaser shall maintain,
      and
      shall cause its officers, employees, representatives, consultants and advisors
      to maintain, all information obtained by Purchaser pursuant to any Assessment
      or
      other due diligence activity as strictly confidential in perpetuity, unless
      disclosure of any facts discovered through such Assessment is required under
      any
      Environmental Laws. Purchaser shall provide Seller with a copy of the final
      draft of all environmental reports prepared by, or on behalf of, Purchaser
      with
      respect to any Assessment or Invasive Activity conducted on the Properties.
      In
      the event that any necessary disclosures under applicable Environmental Laws are
      required with respect to matters discovered by any Assessment conducted by,
      for
      or on behalf of Purchaser, Purchaser agrees that Seller shall be the responsible
      party for disclosing such matters to the appropriate Governmental
      Bodies.




Page
          28 of
          65




**Section
      4.2**  **NORM,
      Wastes and Other Substances** **.**





Purchaser
      acknowledges that the Assets have been used for exploration, development, and
      production Hydrocarbons and that there may be petroleum, produced water, wastes,
      or other substances or materials located in, on or under the Properties or
      associated with the Assets. Equipment and sites included in the Assets may
      contain asbestos, hazardous substances, or NORM. NORM may affix or attach itself
      to the inside of wells, materials, and equipment as scale, or in other forms.
      The wells, materials, and equipment located on the Properties or included in
      the
      Assets may contain NORM and other wastes or hazardous substances. NORM
      containing material and/or other wastes or hazardous substances may have come
      in
      contact with various environmental media, including without limitation, water,
      soils or sediment. Special procedures may be required for the assessment,
      remediation, removal, transportation, or disposal of environmental media,
      wastes, asbestos, hazardous substances, and NORM from the Assets.





**Section
      4.3**  **Environmental
      Defects** .





(a) If,
      as a
      result of its investigation pursuant to **Section
      4.1** ,
      Purchaser determines that with respect to the Assets, there exists a violation
      of an Environmental Law (other than with respect to NORM) (in each case, an
      “Environmental Defect”), then on or prior to the Title Claim Date, Purchaser may
      notify Seller in writing of such Environmental Defect (an “Environmental Defect
      Notice”). For all purposes of this Agreement, Purchaser shall be deemed to have
      waived any Environmental Defect which Purchaser fails to timely and properly
      assert as an Environmental Defect by an Environmental Defect Notice received
      by
      Seller on or before the Title Claim Date. To be effective, each such notice
      shall set forth (i) a description of the matter constituting the alleged
      Environmental Defect, (ii) a description of each Asset (or portion thereof)
      affected by the alleged Environmental Defect, (iii) the proportionate share
      attributable to the Assets of the estimated Lowest Cost Response to eliminate
      the alleged Environmental Defect (the “Environmental Defect Amount”), and (iv)
      supporting documents reasonably necessary for Seller to verify the existence
      of
      the alleged Environmental Defect and the Environmental Defect Amount. Purchaser
      shall furnish Seller once every two (2) weeks from and after the date hereof
      until the Environmental Claim Date with Environmental Defect Notices with
      respect to any Environmental Defects that any employee or representative of
      Purchaser or its Affiliates discover or become aware of during such two (2)
      week
      period.




(b) Seller
      shall have the right, but not the obligation, to attempt, at its sole cost,
      to
      cure or remediate at any time prior to Closing any Environmental Defects of
      which it has been advised by Purchaser pursuant to an Environmental Defect
      Notice delivered before the Title Claim Date.




(c) In
      the
      event that any Environmental Defect asserted by Purchaser pursuant to an
      Environmental Defect Notice delivered before the Title Claim Date is not waived
      by Purchaser or cured on or before the Closing Date, Seller shall, at its sole
      election, elect (at the Closing, for Environmental Defects with respect to
      which
      no dispute exists) to do one of the following:




Page
          29 of
          65




(i)  subject
      to the Individual Environmental Deductible and Aggregate Deductible, reduce
      the
      Purchase Price by the amount of the Environmental Defect Amount relating to
      such
      Environmental Defect as agreed upon by Seller and Purchaser or determined
      pursuant to **Section
      4.3(e)** ;




(ii)  provided
      that the parties shall have agreed to the general plan of remediation with
      respect to such Environmental Defect and the time period by which such
      remediation shall take place, cure such Environmental Defect after Closing;
      or




(iii)  if
      applicable, terminate this Agreement on account of the condition set forth
      in **Section 8.1(e)** not
      being satisfied.




(d)  **Section
      4.3(c)** shall be
      the exclusive right and remedy of Purchaser with respect to Environmental
      Defects asserted by Purchaser pursuant to **Section
      4.3(a)** .




(e)  Prior
      to
      Closing, Seller and Purchaser shall attempt to agree on all Environmental
      Defects and Environmental Defect Amounts that are the subject of timely and
      properly asserted Environmental Defect Notices. If Seller and Purchaser are
      unable to agree by Closing, the Environmental Defects and/or Environmental
      Defect Amounts in dispute shall be exclusively and finally resolved by
      arbitration pursuant to this **Section
      4.3(e)** .
      The
      arbitrator shall be an environmental consultant approved in writing by Seller
      and Purchaser that is experienced in environmental corrective action at oil
      and
      gas properties in the relevant jurisdiction and that shall not have performed
      professional services for either party or any of their respective Affiliates
      during the previous five years (the “Independent Expert”). The arbitration
      proceeding shall be held in Houston, Texas and shall be conducted in accordance
      with the Commercial Arbitration Rules of the American Arbitration Association,
      to the extent such rules do not conflict with the terms of this **Section
      4.3(e)** .
      The
      Independent Expert’s determination shall be made within twenty (20) Business
      Days after submission of the matters in dispute and shall be final and binding
      upon both parties, without right of appeal. In making his determination, the
      Independent Expert may consider such matters as in the opinion of the
      Independent Expert are necessary or helpful to make a proper determination.
      Additionally, the Independent Expert may consult with and engage disinterested
      third parties to advise the Independent Expert. The Independent Expert shall
      act
      as an expert for the limited purpose of determining the disputed matters
      submitted by either party pursuant to this **Section
      4.3(e)** and may
      not award damages, interest or penalties to either party with respect to any
      matter. Seller and Purchaser shall each bear its own legal fees and other costs
      of presenting its case to the Independent Expert. Each party shall bear one-half
      of the costs and expenses of the Independent Expert.




(f)  Notwithstanding
      anything to the contrary, in no event shall there be any adjustments to the
      Purchase Price or other remedies provided by Seller for (i) individual
      Environmental Defects for which the Environmental Defect Amount does not exceed
      $200,000 (the “Individual Environmental Deductible”) and (ii) any Environmental
      Defect unless the aggregate Environmental Defect Amount attributable to all
      such
      Environmental Defects, taken together with the aggregate Title Defect Amounts
      attributable to all uncured Title Defects, exceeds the Aggregate Deductible.




**Section
      4.4**  **Inspection
      Indemnity** **.**





**PURCHASER
      HEREBY AGREES TO DEFEND, INDEMNIFY, RELEASE, PROTECT, SAVE AND HOLD HARMLESS
      THE
      SELLER INDEMNITEES FROM AND AGAINST ANY AND ALL LOSSES AND CLAIMS ARISING OUT
      OF
      OR RELATING TO ANY DUE DILIGENCE ACTIVITY CONDUCTED BY PURCHASER OR ITS AGENTS,
      WHETHER BEFORE OR AFTER THE EXECUTION OF THIS AGREEMENT, INCLUDING, WITHOUT
      LIMITATION, ANY LOSSES RESULTING, IN WHOLE OR IN PART, FROM THE NEGLIGENCE
      OR
      STRICT LIABILITY OF SELLER.**




Page
          30 of
          65




**ARTICLE
      5**


**REPRESENTATIONS
      AND WARRANTIES OF SELLER**





**Section
      5.1**  **Generally** **.**




(a)
      Any
      representation or warranty qualified “to the knowledge of Seller” or “to
      Seller’s knowledge” or with any similar knowledge qualification is limited to
      matters within the actual knowledge of the officers of Seller or those employees
      of Seller who have responsibility for the Assets and who have the following
      titles: General Manager, Field Superintendent (Lonestars & Central), Field
      Superintendent (Brookeland), Regulatory Affairs Manager, Director, EHS &
Regulatory, Director, Land Administration, and A&D Accounting Supervisor.
“Actual knowledge” for purposes of this Agreement means information actually
      personally known by such officers or designated personnel.




(b)
      Inclusion of a matter on a Schedule in relation to a representation or warranty
      which addresses matters having a Material Adverse Effect shall not be deemed
      an
      indication that such matter does, or may, have a Material Adverse Effect.
      Likewise, the inclusion of a matter on a Schedule in relation to a
      representation or warranty shall not be deemed an indication that such matter
      necessarily would, or may, breach such representation or warranty absent its
      inclusion on such Schedule. Matters may be disclosed on a Schedule to this
      Agreement for purposes of information only.




(c)
      Subject to the foregoing provisions of this **Section
      5.1** ,
      the
      disclaimers and waivers contained in **Sections
      11.8** and **11.9** and the
      other terms and conditions of this Agreement, Seller represents and warrants
      to
      Purchaser the matters set out in **Sections
      5.2** through **5.20** .




**Section
      5.2**  **Existence
      and Qualification** **.**




Each
      Seller is a limited partnership duly organized, validly existing and in good
      standing under the laws of the State of Delaware and is duly qualified to do
      business as a foreign limited partnership where the Assets are located, except
      where the failure to so qualify would not have a Material Adverse
      Effect.




**Section
      5.3**  **Power** **.**




Each
      Seller has the limited partnership power to enter into and perform this
      Agreement and consummate the transactions contemplated by this
      Agreement.




**Section
      5.4**  **Authorization
      and Enforceability** **.**




The
      execution, delivery and performance of this Agreement, and the performance
      of
      the transactions contemplated hereby, have been duly and validly authorized
      by
      all necessary limited partnership action on the part of Seller. This Agreement
      has been duly executed and delivered by Seller (and all documents required
      hereunder to be executed and delivered by Seller at Closing will be duly
      executed and delivered by Seller) and this Agreement constitutes, and at the
      Closing such documents will constitute, the valid and binding obligations of
      Seller, enforceable against Seller in accordance with their terms except as
      such
      enforceability may be limited by applicable bankruptcy or other similar laws
      affecting the rights and remedies of creditors generally as well as to general
      principles of equity (regardless of whether such enforceability is considered
      in
      a proceeding in equity or at law).




Page
          31 of
          65




**Section
      5.5**  **No
      Conflicts** **.**




To
      Seller’s knowledge, subject to compliance with the Preference Rights and
      Transfer Requirements set forth in **Schedule
      5.13** ,
      the
      execution, delivery and performance of this Agreement by Seller, and the
      transactions contemplated by this Agreement will not (i) violate any provision
      of the limited partnership agreement or similar governing documents of Seller,
      (ii) result in default (with due notice or lapse of time or both) or the
      creation of any lien or encumbrance or give rise to any right of termination,
      cancellation or acceleration under any of the terms, conditions or provisions
      of
      any note, bond, mortgage, indenture, license or agreement to which Seller is
      a
      party or which affect the Assets, (iii) violate any judgment, order, ruling,
      or
      decree applicable to Seller as a party in interest, (iv) violate any Laws
      applicable to Seller or any of the Assets, except for (a) rights to consent
      by,
      required notices to, filings with, approval or authorizations of, or other
      actions by any Governmental Body where the same are not required prior to the
      assignment of the related Asset or they are customarily obtained subsequent
      to
      the sale or conveyance thereof and (b) any matters described in clauses (ii),
      (iii) or (iv) above which would not have a Material Adverse Effect.




**Section
      5.6**  **Liability
      for Brokers’ Fees** .




Purchaser
      shall not directly or indirectly have any responsibility, liability or expense,
      as a result of undertakings or agreements of Seller, for brokerage fees,
      finder’s fees, agent’s commissions or other similar forms of compensation in
      connection with this Agreement or any agreement or transaction contemplated
      hereby.




**Section
      5.7**  **Litigation** .




Except
      as
      set forth in **Schedule
      5.7,** to
      Seller’s knowledge (only with respect to Non-Operated Assets), no proceeding,
      action, suit, or other legal proceeding of any kind or nature before any
      Governmental Body or arbitrator (including any take-or-pay claims) which could
      have a Material Adverse Effect is pending or, to Seller’s knowledge, threatened
      to which Seller is a party and which relates to the Assets.




**Section
      5.8**  **Taxes
      and Assessments.**




With
      respect to all Taxes related to the Assets, to the knowledge of Seller, (a)
      all
      reports, returns, statements (including estimated reports, returns or
      statements), and other similar filings (the “Tax Returns”) relating to the
      Assets required to be filed by Seller with respect to such Taxes have been
      timely filed with the appropriate Governmental Body in all jurisdictions in
      which such Tax Returns are required to be filed; and (b) such Tax Returns are
      true and correct in all material respects, and (c) all Taxes reported on such
      Tax Returns have been paid, except those being contested in good
      faith.





To
      Seller’s knowledge, with respect to all Taxes related to the Assets, except as
      set forth on **Schedule
      5.8** ,
      (a)
      there are not currently in effect any extension or waiver of any statute of
      limitations of any jurisdiction regarding the assessment or collection of any
      such Tax; (b) there are no administrative proceedings or lawsuits pending
      against the Assets or Seller by any taxing authority; and (c) there are no
      Tax
      liens on any of the Assets except for liens for Taxes not yet due.




Page
          32 of
          65




**Section
      5.9**  **Compliance
      with Laws** .




Except
      as
      disclosed on **Schedule
      5.9** ,
      to the
      knowledge of Seller (only with respect to the Non-Operated Assets), the Assets
      are, and the operation of the Assets is, in compliance with the provisions
      and
      requirements of all Laws of all Governmental Bodies having jurisdiction with
      respect to the Assets, or the ownership, operation, development, maintenance,
      or
      use of any thereof, except where the failure to so comply would not have a
      Material Adverse Effect. Notwithstanding the foregoing, Seller makes no
      representation or warranty, express or implied, under this Section relating
      to
      any Environmental Liabilities or Environmental Law.




**Section
      5.10**  **Contracts** **.**




Except
      as
      disclosed on **Schedule
      5.10(a)** ,
      to the
      knowledge of Seller, Seller has paid its share of all costs payable by it under
      the contracts and agreements described in **Schedule
      1.2(d)** ,
      except
      those being contested in good faith. Seller is in compliance with all Contracts
      listed on **Schedule 1.2(d)** except
      as disclosed on **Schedule
      5.10(a)** and
      except such non-compliance as would not, individually or the aggregate, have
      a
      Material Adverse Effect. Except for contracts and agreements the existence
      of
      which would not have a Material Adverse Effect, **Schedule
      5.10(b)** sets
      forth all of the following contracts and agreements to which any of the Assets
      will be bound as of the Closing: (i) any agreement with any Affiliate of Seller;
      (ii) any agreement or contract for the sale, exchange, or other disposition
      of
      Hydrocarbons produced from or attributable to Seller’s interest in the Assets
      that is not cancelable without penalty or other material payment on not more
      than 30 days prior written notice; and (iii) any tax partnership agreement
      of or
      binding upon Seller affecting any of the Assets.




**Section
      5.11**  **Payments
      for Hydrocarbon Production** **.**




Except
      as
      set forth on **Schedule
      5.11** ,
      to the
      knowledge of Seller, (a) all rentals, royalties, excess royalty, overriding
      royalty interests, Hydrocarbon production payments, and other payments due
      and/or payable by Seller to overriding royalty holders and other interest owners
      on or prior to the Effective Time under or with respect to the Assets and the
      Hydrocarbons produced therefrom or attributable thereto, have been paid, and
      (b)
      Seller is not obligated under any contract or agreement for the sale of gas
      from
      the Assets containing a take-or-pay, advance payment, prepayment, or similar
      provision, or under any gathering, transmission, or any other contract or
      agreement with respect to any of the Assets to gather, deliver, process, or
      transport any gas without then or thereafter receiving full payment
      therefor.





**Section
      5.12**  **Governmental
      Authorizations.**




To
      Seller’s knowledge (only with respect to the Non-Operated Assets), except as
      disclosed on **Schedule
      5.12** ,
      Seller
      has obtained and is maintaining all federal, state and local governmental
      licenses, permits, franchises, orders, exemptions, variances, waivers,
      authorizations, certificates, consents, rights, privileges and applications
      therefor (the “Governmental Authorizations”) that are presently necessary or
      required for the ownership and operation of the Seller Operated Assets as
      currently owned and operated, the loss of which would, individually or in the
      aggregate, have a Material Adverse Effect. Except as disclosed in **Schedule
      5.7(a)** , **Schedule
      5.7(b)** or **Schedule
      5.12** and
      except as would not, individually or in




Page
          33 of
          65




the
      aggregate, have a Material Adverse Effect, (i) Seller has operated the Seller
      Operated Assets in accordance with the conditions and provisions of such
      Governmental Authorizations, and (ii) no written notices of violation have
      been
      received by Seller, and no proceedings are pending or, to Seller’s knowledge,
      threatened in writing that might result in any modification, revocation,
      termination or suspension of any such Governmental Authorizations or which
      would
      require any corrective or remediation action by Seller.




**Section
      5.13**  **Preference
      Rights and Transfer Requirements** .




To
      Seller’s knowledge, none of the Assets, or any portion thereof, is subject to
      any Preference Right or Transfer Requirement which may be applicable to the
      transactions contemplated by this Agreement, except for (i) Preference Rights
      and Transfer Requirements contained in easements, rights-of-way or equipment
      leases and (ii) Preference Rights and Transfer Requirements as are set forth
      on **Schedule
      5.13** .




**Section
      5.14**  **[RESERVED]** .





**Section
      5.15**  **Outstanding
      Capital Commitments** .




As
      of the
      date hereof, there are no outstanding AFEs or other commitments to make capital
      expenditures which are binding on the Assets and which Seller reasonably
      anticipates will individually require expenditures by the owner of the Assets
      after the Closing Date in excess of $1,000,000.00 other than those shown on **Schedule
      5.15** .




**Section
      5.16**  **Imbalances** .




To
      Seller’s knowledge, **Schedule
      5.16** accurately sets forth in all material respects all of Seller’s Imbalances as of
      the respective dates reflected therein arising with respect to the Assets and,
      except as disclosed in **Schedule
      5.16,** as of
      the respective dates reflected therein, (i) no Person is entitled to receive
      any
      material portion of the Seller’s Hydrocarbons produced from the Assets or to
      receive material cash or other payments to “balance” any disproportionate
      allocation of Hydrocarbons produced from the Assets under any operating
      agreement, gas balancing or storage agreement, gas processing or dehydration
      agreement, gas transportation agreement, gas purchase agreement, or other
      agreements, whether similar or dissimilar, (ii) Seller is not obligated to
      deliver any material quantities of gas or to pay any material penalties or
      other
      amounts, in connection with the violation of any of the terms of any gas
      contract or other agreement with shippers with respect to the Assets, and (iii)
      Seller is not obligated to pay any material penalties or other material payments
      under any gas transportation or other agreement as a result of the delivery
      of
      quantities of gas from the Wells in excess of the contract
      requirements.




**Section
      5.17**  **Condemnation** .




To
      Seller’s knowledge, there is no actual or threatened taking (whether permanent,
      temporary, whole or partial) of any part of the Properties by reason of
      condemnation or the threat of condemnation.





Page
          34 of
          65




**Section
      5.18**  **Bankruptcy** .




To
      Seller’s knowledge, there are no bankruptcy, reorganization, or similar
      arrangement proceedings pending, being contemplated by or threatened against
      Seller or any Affiliate of Seller.




**Section
      5.19**  **PUHCA/NGA** .




Seller
      is
      not a “holding company,” or a “subsidiary company” of a “holding company,” or an
“affiliate” of a “holding company,” or an “affiliate” of a “subsidiary” of a
“holding company,” or a “public-utility company” within the meaning of the
      Public Utility Holding Company Act of 1935, as amended. No consent is required
      in connection with the transaction contemplated hereby under the Natural Gas
      Policy Act of 1978, as amended. Seller is not an interstate pipeline company
      within the meaning of the Natural Gas Act of 1938.




**Section
      5.20**  **Investment
      Company** .




Seller
      is
      not an investment company or a company controlled by an investment company
      within the meaning of the Investment Company Act of 1940, as
      amended.




**ARTICLE
      6**


**REPRESENTATIONS
      AND WARRANTIES OF PURCHASER**




Purchaser
      represents and warrants to Seller the following:




**Section
      6.1**  **Existence
      and Qualification** .




(a)  Each
      Purchaser other than Wachovia is a limited partnership duly organized, validly
      existing and in good standing under the laws of the state of its formation;
      and
      each Purchaser other than Wachovia is duly qualified to do business as a foreign
      limited partnership in every jurisdiction in which it is required to qualify
      in
      order to conduct its business except where the failure to so qualify would
      not
      have a material adverse effect on such Purchaser or its properties; and each
      Purchaser other than Wachovia is duly qualified to do business as a foreign
      limited partnership in the respective jurisdictions where the Assets are
      located.





(b)  Wachovia
      is a limited liability company duly organized, validly existing and in good
      standing under the laws of the state of its formation; and Wachovia is duly
      qualified to do business as a foreign limited liability company in every
      jurisdiction in which it is required to qualify in order to conduct its business
      except where the failure to so qualify would not have a material adverse effect
      on Wachovia or its properties; and Wachovia is duly qualified to do business
      as
      a foreign limited liability company in the respective jurisdictions where the
      Assets are located.




**Section
      6.2**  **Power** .




Each
      Purchaser has the limited partnership or limited liability company power to
      enter into and perform this Agreement and consummate the transactions
      contemplated by this Agreement.




Page
          35 of
          65




**Section
      6.3**  **Authorization
      and Enforceability** .




The
      execution, delivery and performance of this Agreement, and the performance
      of
      the transaction contemplated hereby, have been duly and validly authorized
      by
      all necessary limited partnership or limited liability company action on the
      part of Purchaser. This Agreement has been duly executed and delivered by
      Purchaser (and all documents required hereunder to be executed and delivered
      by
      Purchaser at Closing will be duly executed and delivered by Purchaser) and
      this
      Agreement constitutes, and at the Closing such documents will constitute, the
      valid and binding obligations of Purchaser, enforceable in accordance with
      their
      terms except as such enforceability may be limited by applicable bankruptcy
      or
      other similar laws affecting the rights and remedies of creditors generally
      as
      well as to general principles of equity (regardless of whether such
      enforceability is considered in a proceeding in equity or at law).




**Section
      6.4**  **No
      Conflicts** .




The
      execution, delivery and performance of this Agreement by Purchaser, and the
      transactions contemplated by this Agreement will not (i) violate any provision
      of the limited partnership agreement, operating agreement or similar governing
      documents of Purchaser, (ii) result in a default (with due notice or lapse
      of
      time or both) or the creation of any lien or encumbrance or give rise to any
      right of termination, cancellation or acceleration under any of the terms,
      conditions or provisions of any note, bond, mortgage, indenture, license or
      agreement to which Purchaser is a party, (iii) violate any judgment, order,
      ruling, or regulation applicable to Purchaser as a party in interest, or (iv)
      violate any Law applicable to Purchaser or any of its assets, or (v) require
      any
      filing with, notification of or consent, approval or authorization of any
      Governmental Body or authority, except any matters described in clauses (ii),
      (iii), (iv) or (v) above which would not have a material adverse effect on
      Purchaser or the transactions contemplated hereby.




**Section
      6.5**  **Liability
      for Brokers’ Fees** .




Seller
      shall not directly or indirectly have any responsibility, liability or expense,
      as a result of undertakings or agreements of Purchaser, for brokerage fees,
      finder’s fees, agent’s commissions or other similar forms of compensation in
      connection with this Agreement or any agreement or transaction contemplated
      hereby.




**Section
      6.6**  **Litigation** .




There
      are
      no actions, suits or proceedings pending, or to the actual knowledge of
      Purchaser’s officers, threatened in writing before any Governmental Body against
      Purchaser or any Affiliate of Purchaser which are reasonably likely to impair
      materially Purchaser’s ability to perform its obligations under this
      Agreement.





**Section
      6.7**  **Financing** .




Purchaser
      has sufficient cash, available lines of credit or other sources of immediately
      available funds (in United States dollars) to enable it to pay the Closing
      Payment to Seller at the Closing.




Page
          36 of
          65




**Section
      6.8**  **Several
      Liability** .





Notwithstanding
      anything to the contrary contained elsewhere in this Agreement, except as
      provided in **Section
      12.10** ,
      with
      respect to all of Purchaser’s representations, warranties and covenants
      contained in this Agreement, each Purchaser shall be severally, but not jointly,
      obligated to Seller (and with respect to Purchaser’s representations, warranties
      and covenants contained in this Agreement relating specifically to the Assets,
      as to such Purchaser’s Purchaser Share only).





**Section
      6.9**  **Limitation** .




Except
      for the representations and warranties expressly made by Seller in **Article
      5** of
      this
      Agreement, or confirmed in any certificate furnished or to be furnished to
      Purchaser pursuant to this Agreement, Purchaser represents and acknowledges
      that
      (i) there are no representations or warranties, express, statutory or implied,
      as to the Assets or prospects thereof, and (ii) Purchaser has not relied upon
      any oral or written information provided by Seller. Without limiting the
      generality of the foregoing, Purchaser represents and acknowledges that Seller
      has made and will make no representation or warranty regarding any matter or
      circumstance relating to Environmental Laws, Environmental Liabilities, the
      release of materials into the environment or protection of human health, safety,
      natural resources or the environment or any other environmental condition of
      the
      Assets. Purchaser further represents and acknowledges that it is knowledgeable
      of the oil and gas business and of the usual and customary practices of
      producers such as Seller and that it has had access to the Assets, the officers
      and employees of Seller, and the books, records and files of Seller relating
      to
      the Assets, and in making the decision to enter into this Agreement and
      consummate the transactions contemplated hereby, Purchaser has relied solely
      on
      the basis of its own independent due diligence investigation of the
      Assets.




**Section
      6.10**  **SEC
      Disclosure** **.**





Purchaser
      is acquiring the Assets for its own account for use in its trade or business,
      and not with a view toward or for sale associated with any distribution thereof,
      nor with any present intention of making a distribution thereof within the
      meaning of the Securities Act of 1933, as amended and applicable state
      securities laws.





**Section
      6.11**  **Bankruptcy** **.**





There
      are
      no bankruptcy, reorganization or receivership proceedings pending against,
      being
      contemplated by, or threatened against Purchaser.





**Section
      6.12**  **Qualification** **.**





Purchaser
      is now, and hereafter shall continue to be, qualified to own and assume
      operatorship of federal and state oil, gas and mineral leases in all
      jurisdictions where ownership of the Assets to be transferred to it require
      same, and the consummation of the transactions contemplated in this Agreement
      will not cause Purchaser to be disqualified as such an owner or operator. To
      the
      extent required by the applicable state and federal government, Purchaser
      currently has, and will continue to maintain, lease bonds, area-wide bonds
      or
      any other surety bonds as may be required by, and in accordance with, such
      state
      or federal regulations governing the ownership and operation of such
      leases.





Page
          37 of
          65




**ARTICLE
      7**


**COVENANTS
      OF THE PARTIES**




**Section
      7.1**  **Access** **.**




Between
      the date of execution of this Agreement and continuing until the Closing Date,
      Seller will give Purchaser and its representatives access to the Assets and
      access to the Records in Seller’s possession, for the purpose of conducting an
      investigation of the Assets, but only to the extent that Seller may do so
      without violating any obligations to any third party and to the extent that
      Seller has authority to grant such access without breaching any restriction
      binding on Seller. Such access by Purchaser shall be limited to Seller’s normal
      business hours, and any weekends and after hours requested by Purchaser that
      can
      be reasonably accommodated by Seller, and Purchaser’s investigation shall be
      conducted in a manner that minimizes interference with the operation of the
      Assets. All information obtained by Purchaser and its representatives under
      this
      Section shall be subject to the terms of **Section
      11.4(b)(vi)** and the
      terms of that certain confidentiality agreement between Seller and EnerVest
      Energy Partners, LP dated February 8, 2007 (the "Confidentiality
      Agreement").





**Section
      7.2**  **Government
      Reviews** .




Seller
      and Purchaser shall in a timely manner (a) make all required filings, if any,
      with and prepare applications to and conduct negotiations with, each
      governmental agency as to which such filings, applications or negotiations
      are
      necessary or appropriate in the consummation of the transactions contemplated
      hereby specifically including but not limited to the HSR Act, (b) provide such
      information as each may reasonably request to make such filings, prepare such
      applications and conduct such negotiations, and (c) request early termination
      or
      waiver of any applicable waiting period under the HSR Act. Each party shall
      cooperate with and use all commercially reasonable efforts to assist the other
      with respect to such filings, applications and negotiations.





**Section
      7.3**  **Notification
      of Breaches** .





Until
      the
      Closing,




(a)  Purchaser
      shall notify Seller promptly after Purchaser obtains actual knowledge that
      any
      representation or warranty of Seller contained in this Agreement is untrue
      in
      any material respect or will be untrue in any material respect as of the Closing
      Date or that any covenant or agreement to be performed or observed by Seller
      prior to or on the Closing Date has not been so performed or observed in any
      material respect.




(b)  Seller
      shall notify Purchaser promptly after Seller obtains actual knowledge that
      any
      representation or warranty of Purchaser contained in this Agreement is untrue
      in
      any material respect or will be untrue in any material respect as of the Closing
      Date or that any covenant or agreement to be performed or observed by Purchaser
      prior to or on the Closing Date has not been so performed or observed in any
      material respect.




Page
          38 of
          65




(c)  If
      any of
      Purchaser’s or Seller’s representations or warranties is untrue or shall become
      untrue in any material respect between the date of execution of this Agreement
      and the Closing Date, or if any of Purchaser’s or Seller’s covenants or
      agreements to be performed or observed prior to or on the Closing Date shall
      not
      have been so performed or observed in any material respect, but if such breach
      of representation, warranty, covenant or agreement shall (if curable) be cured
      by the Closing (or, if the Closing does not occur, by the date set forth in **Section
      10.1** ),
      then
      such breach shall be considered not to have occurred for all purposes of this
      Agreement.





**Section
      7.4**  **Letters-in-Lieu;
      Assignments; Operatorship** **.**




(a)  Seller
      will execute on the Closing Date letters in lieu of division and transfer orders
      relating to the Assets on forms prepared by Seller and reasonably satisfactory
      to Seller to reflect the transaction contemplated hereby.




(b)  Seller
      will prepare and Seller and Purchaser will execute on the Closing Date all
      assignments necessary to convey to Purchaser all Leases in the form as
      prescribed by the applicable Governmental Body and otherwise acceptable to
      Purchaser and Seller.





(c)  Seller
      makes no representations or warranties to Purchaser as to transferability or
      assignability of operatorship of any Seller Operated Assets. Rights and
      obligations associated with operatorship of such Properties are governed by
      operating and similar agreements covering the Properties and will be decided
      in
      accordance with the terms of such agreements. However, Seller will assist
      Purchaser in its efforts to have EnerVest XI-WI succeed Seller as operator
      of
      any Wells included in the Assets. Purchaser shall, promptly following Closing,
      file all appropriate forms and declarations or bonds with federal and state
      agencies relative to EnerVest XI-WI’s assumption of operatorship. For all Seller
      Operated Assets, Seller shall execute and deliver to Purchaser and Purchaser
      shall promptly file the appropriate forms with the applicable regulatory agency
      transferring operatorship of such Assets to EnerVest XI-WI.





**Section
      7.5**  **Public
      Announcements** **.**




Until
      the
      Closing, neither party shall make any press release or other public announcement
      regarding the existence of this Agreement, the contents hereof or the
      transactions contemplated hereby without the prior written consent of the other;
      provided, however, the foregoing shall not restrict disclosures by Purchaser
      or
      Seller which are required by applicable securities or other laws or regulations
      or the applicable rules of any stock exchange having jurisdiction over the
      disclosing party or its Affiliates; and provided, further, that Purchaser may
      disclose the existence and contents of this Agreement and the transactions
      contemplated hereby to the Standard & Poor’s and Moody’s rating agencies
      (provided that such agencies are obligated to keep such information
      confidential). At or after Closing, the content of any press release or public
      announcement shall be subject to the prior review and reasonable approval of
      Seller and Purchaser.




**Section
      7.6**  **Operation
      of Business** **.**




Except
      as
      set forth on **Schedule
      7.6** ,
      until
      the Closing, Seller (i) will operate its business in the ordinary course, (ii)
      will not, without the prior written consent of Purchaser, which consent shall
      not be unreasonably withheld, commit to any operation, or series of related
      operations, reasonably anticipated by Seller to require future capital
      expenditures by the owner of the Assets in excess of $150,000.00, proportionate
      to Seller’s working interest, or make any capital expenditures in excess of
      $150,000.00, proportionate to Seller’s working interest, or terminate,
      materially amend, execute or extend any material agreements affecting the
      Assets, (iii) will maintain insurance coverage on the Assets presently furnished
      by nonaffiliated third parties in the amounts and of the types presently in
      force, (iv) will use commercially reasonable efforts to maintain in full force
      and effect all Leases, (v) will maintain all material governmental permits
      and
      approvals affecting the Assets, (vi) will not transfer, farmout, sell,
      hypothecate, encumber or otherwise dispose of any material Assets except for
      sales and dispositions of Hydrocarbon production and Equipment made in the
      ordinary course of business consistent with past practices and (vii) will not
      commit to do any of the foregoing. Purchaser’s approval of any action restricted
      by this **Section
      7.6**shall be
      considered granted within ten (10) days (unless a shorter time is reasonably
      required by the circumstances and such shorter time is specified in Seller’s
      written notice) of Seller’s notice to Purchaser requesting such consent unless
      Purchaser notifies Seller to the contrary in writing during that period. In
      the
      event of an emergency, Seller may take such action as a prudent operator would
      take and shall notify Purchaser of such action promptly
      thereafter.




Page
          39 of
          65




Notwithstanding
      anything to the contrary in this Agreement, Seller shall have no liability
      to
      Purchaser for the incorrect payment of delay rentals, royalties, shut-in
      payments or similar payments made during the period from the Effective Time
      to
      the Closing Date or for failure to make such payments through mistake or
      oversight (including Seller's negligence, but excluding Seller’s willful
      misconduct).




Purchaser
      acknowledges that Seller may own an undivided interest in certain of the Assets
      and Purchaser agrees that the acts or omissions of the other working interest
      owners who are not affiliated with Seller shall not constitute a violation
      of
      the provisions of this **Article
      7.6** nor
      shall
      any action required by a vote of working interest owners constitute such a
      violation so long as Seller has voted its interest in a manner consistent with
      the provisions of this **Article
      7.6** .





**Section
      7.7**  **Hedges** **.**




(a)  Contemporaneously
      with the execution of this Agreement, Seller
      shall enter into the hedging transactions set forth on **Part
      I** of **Schedule 7.7** with
      each counterparty specified therein and at the written direction of Purchaser
      received by Seller following the execution of this Agreement and prior to the
      Closing Date, Seller agrees to enter into such additional hedging transactions
      that relate to the Assets that are described on **Part
      II** of **Schedule
      7.7** (the
      hedging transactions set forth on **Part
      I** and **Part
      II** of **Schedule
      7.7** that
      Seller enters into pursuant to this **Section
      7.7(a)** are
      collectively called the “Hedging Transactions”) with one of the counterparties
      listed on **Part
      II** of **Schedule
      7.7** (the
      counterparties to the Hedging Transactions are collectively called the
“Counterparties”). Purchaser covenants and agrees that each of the
      Counterparties has agreed and will (i) allow the assignment by Seller to
      EnerVest for the benefit of Purchaser at the Closing of all of the trades that
      are the subject of the Hedging Transactions and (ii) release Seller from any
      and
      all obligations and liabilities related or attributable to such Hedging
      Transactions upon such assignment. The respective agreements between Seller
      and
      each of the Counterparties shall be evidenced by a Novation Agreement that
      is in
      form and substance reasonably acceptable to Seller.




(b)  At
      the
      Closing, EnerVest, for the benefit of Purchaser, shall accept an assignment
      from
      Seller of all of the trades that are the subject of the Hedging Transactions
      and
      shall assume all obligations and liabilities attributable thereto pursuant
      to
      documentation required by the Counterparties.




Page
          40 of
          65




(c)  Within
      five (5) Business Days of the termination by Purchaser or Seller, as the case
      may be, of this Agreement in accordance with **Section 10.1** ,
      Seller
      shall furnish to Purchaser written notice of whether it elects to unwind one
      or
      more of the Hedging Transactions. If Seller notifies Purchaser that it does
      not
      elect to unwind one or more of the Hedging Transactions, Purchaser shall have
      no
      further obligations whatsoever to Seller or to Counterparties with respect
      to
      the Hedging Transactions that Seller does not elect to unwind. However, if
      Seller notifies Purchaser that it elects to unwind one or more of the Hedging
      Transactions, Purchaser shall be obligated for and shall promptly pay, and
      Purchaser does hereby agree to indemnify and hold harmless Seller from and
      against, any and all Losses suffered by Seller resulting from or attributable
      to
      the Hedging Transactions that Seller elects to unwind and the unwind thereof.




**Section
      7.8**  **Preference
      Rights and Transfer Requirements** **.**




(a) Purchaser’s
      purchase of the Assets is expressly subject to all validly existing and
      applicable Preference Rights and Transfer Requirements. Prior to the Closing
      Date, Seller shall initiate all procedures which in Seller’s good faith judgment
      are reasonably required to comply with or obtain the waiver of all Preference
      Rights and Transfer Requirements set forth in **Schedule
      5.13** with
      respect to the transactions contemplated by this Agreement. Seller shall not
      be
      obligated to pay any consideration to (or incur any cost or expense for the
      benefit of) the holder of any Preference Right or Transfer Requirement in order
      to obtain the waiver thereof or compliance therewith.




(b) The
      portion of the Purchase Price to be allocated to any Asset or portion thereof
      affected by a Preference Right (a “Preference Property”) or that becomes a
      Retained Asset shall be the portion of the Purchase Price allocated thereto
      in **Exhibit
      A-1** .
      If a
      Preference Property or a Retained Asset affects only a portion of a Property
      and
      a portion of the Purchase Price has not been allocated specifically to such
      portion of a Property in **Exhibit
      A-1** ,
      then
      the portion of the Purchase Price to be allocated to such Preference Property
      or
      Retained Asset shall be determined in a reasonable manner taking into account
      the net acreage (or net acre feet, as appropriate) that the portion of such
      Property affected by such Preference Property or Retained Asset bears to the
      net
      acreage (or net acre feet, as appropriate) in the entire Property. Any
      Preference Property or Retained Asset that is a Property shall include a pro
      rata share of all of Seller’s right, title and interest in, to and under all
      Contracts, Surface Contracts, Equipment, Hydrocarbon production and Records
      included in the Assets that are directly related or attributable to such
      Preference Property or Retained Asset.




(c) If
      the
      holder of a Preference Right who has been offered a Preference Property pursuant
      to **Section
      7.8(a)** elects
      prior to Closing to purchase such Preference Property in accordance with the
      terms of such Preference Right, and Seller and Purchaser receive written notice
      of such election prior to the Closing, such Preference Property will be
      eliminated from the Assets and the Purchase Price shall be reduced by the
      portion of the Purchase Price allocated to such Preference Property pursuant
      to **Section
      7.8(b)** .
      Except
      as provided in **Section
      7.8(d)** ,
      if the
      holder of a Preference Right who has been offered a Preference Property or
      who
      has been requested to waive its Preference Right pursuant to **Section
      7.8(a)** does not
      elect to purchase such Preference Property or waive such Preference Right with
      respect to the transactions contemplated by this Agreement prior to the Closing
      Date and the time in which the




Page
          41 of
          65




Preference
      Right may be exercised has not expired, such Preference Property shall be
      conveyed to Purchaser at Closing subject to the rights, if any, of the holder
      of
      such Preference Right. In such event, Seller shall continue its efforts to
      obtain the waiver of such Preference Rights to the extent provided in **Section
      7.8(a)** and
      Purchaser shall cooperate with such efforts. If the holder of a Preference
      Right
      elects to purchase a Preference Property subject to its Preference Right and
      Closing has already occurred with respect to such Preference Property, Purchaser
      shall be obligated to comply with such Preference Right to the extent, if any,
      that the same remains valid and enforceable with respect to this transaction
      and
      Purchaser shall be entitled to the consideration for the sale of such Preference
      Property from Purchaser to such Preference Right holder.




(d) If




(i)  a
      third
      party brings any suit, action or other proceeding prior to the Closing seeking
      to restrain, enjoin or otherwise prohibit the consummation of the transactions
      contemplated hereby in connection with a claim to enforce a Preference Right;
      or





(ii)  an
      Asset
      is subject to a Transfer Requirement that provides that transfer of such Asset
      without compliance with such Transfer Requirement will result in termination
      or
      other material impairment of any rights in relation to such Asset, and such
      Transfer Requirement is not waived, complied with or otherwise satisfied prior
      to the Closing Date,





then,
      unless otherwise mutually agreed by Seller and Purchaser, the Asset or portion
      thereof affected by such Preference Right or Transfer Requirement (a “Retained
      Asset”) shall be held back from the Assets to be transferred and conveyed to
      Purchaser at Closing and the Purchase Price to be paid at Closing shall be
      reduced by the portion of the Purchase Price which is allocated to such Retained
      Asset pursuant to **Section
      7.8(b)** .
      Any
      Retained Asset so held back at the initial Closing will be conveyed to Purchaser
      at a delayed Closing (which shall become the new Closing Date with respect
      to
      such Retained Asset), within ten (10) days following the date on which the
      suit,
      action or other proceeding, if any, referenced in clause (i) above is settled
      or
      a judgment is rendered (and no longer subject to appeal) permitting transfer
      of
      the Retained Asset to Purchaser pursuant to this Agreement and Seller obtains,
      complies with, obtains a waiver of or notice of election not to exercise or
      otherwise satisfies all remaining Preference Rights and Transfer Requirements
      with respect to such Retained Asset as contemplated by this Section. At the
      delayed Closing, Purchaser shall pay Seller a purchase price equal to the amount
      by which the Purchase Price was reduced on account of the holding back of such
      Retained Asset (as adjusted pursuant to **Section
      2.2** through
      the new Closing Date therefor); provided, however, if all such Preference Rights
      and Transfer Requirements with respect to any Retained Asset so held back at
      the
      initial Closing are not obtained, complied with, waived or otherwise satisfied
      as contemplated by this Section within one hundred eighty (180) days after
      the
      initial Closing has occurred with respect to any Assets, then such Retained
      Asset shall be eliminated from the Assets and this Agreement, unless Seller
      and
      Purchaser mutually agree to proceed with a closing on such Retained Asset in
      which case Purchaser shall be deemed to have waived any objection (and shall
      be
      obligated to indemnify the Seller Indemnitees for all Claims) with respect
      to
      non-compliance with such Preference Rights and Transfer Requirements with
      respect to such Retained Asset.





(e) Purchaser
      acknowledges that Seller desires to sell all of the Assets and would not have
      entered into this Agreement but for Purchaser’s agreement to purchase all of the
      Assets as herein provided. Accordingly, it is expressly understood and agreed
      that Seller does not desire to sell any Preference Property unless the sale
      of
      all of the Assets is consummated by the Closing Date in accordance with the
      terms of this Agreement. In furtherance of the foregoing, Seller’s obligation
      hereunder to sell the Preference Properties to Purchaser is expressly
      conditioned upon the consummation by the Closing Date of the sale of all of
      the
      Assets in accordance with the terms of this Agreement, either by conveyance
      to
      Purchaser or conveyance pursuant to an applicable Preference Right; provided
      that, nothing herein is intended or shall operate to extend or apply any
      Preference Right to any portion of the Assets which is not otherwise burdened
      thereby. Time is of the essence with respect to the parties’ agreement to
      consummate the sale of the Assets by the Closing Date (or by the delayed Closing
      Date pursuant to **Section
      7.8(d)**).




Page
          42 of
          65




**Section
      7.9**  **Tax
      Matters** .




(a)  Subject
      to the provisions of **Section
      12.3** ,
      Seller
      shall be responsible for all Taxes related to the Assets (other than ad valorem,
      property, severance, Hydrocarbon production and similar Taxes based upon or
      measured by the ownership or operation of the Assets or the production of
      Hydrocarbons therefrom, which are addressed in **Section
      1.4** )
      attributable to any period of time at or prior to the Closing Date, and
      Purchaser shall be responsible for all such Taxes related to the Assets
      attributable to any period of time after the Closing Date. Regardless of which
      party is responsible, Seller shall handle payment to the appropriate
      Governmental Body of all Taxes with respect to the Assets which are required
      to
      be paid prior to Closing (and shall file all Tax Returns with respect to such
      Taxes). If requested by Purchaser, Seller will assist Purchaser with preparation
      of all ad valorem and property Tax Returns due on or before December 31, 2007
      (including any extensions requested). Seller shall deliver to Purchaser within
      thirty (30) days of filing copies of all Tax Returns filed by Seller after
      the
      Closing Date relating to the Assets and any supporting documentation provided
      by
      Seller to taxing authorities, excluding Tax Returns related to income tax,
      franchise tax, or other similar Taxes.




(b)  **[RESERVED]**




**Section
      7.10**  **Further
      Assurances** **.**




After
      Closing, Seller and Purchaser each agrees to take such further actions and
      to
      execute, acknowledge and deliver all such further documents as are reasonably
      requested by the other party for carrying out the purposes of this Agreement
      or
      of any document delivered pursuant to this Agreement.





**Section
      7.11**  **[RESERVED].**




**Section
      7.12**  **[RESERVED]** **.**




**Section
      7.13**  **[RESERVED].**





**Section
      7.14**  **Insurance** **.**





Effective
      as of the Closing Date, Purchaser shall carry and maintain the following: (i)
      general liability insurance with combined single limits per occurrence of not
      less than $1,000,000.00 for bodily injury and property damage, including
      property damage by blowout and cratering, completed operations, and contractual
      liability as respects any contract into which the Purchaser may enter under
      the
      terms of this Agreement; and (ii) operators extra expense insurance with limits
      of not less than $1,000,000.00 per occurrence, covering the costs of controlling
      a blowout, and certain other related and/or resulting costs and seepage and
      pollution liability.




Page
          43 of
          65




**ARTICLE
      8**


**CONDITIONS
      TO CLOSING**




**Section
      8.1**  **Conditions
      of Seller to Closing.**




The
      obligations of Seller to consummate the transactions contemplated by this
      Agreement are subject, at the option of Seller, to the satisfaction on or prior
      to Closing of each of the following conditions:





(a)  Representations .
      The
      representations and warranties of Purchaser set forth in **Article
      6** shall be
      true and correct in all material respects, other than representations and
      warranties that are already qualified as to materiality, which shall be true
      and
      correct in all respects, as of the Closing Date as though made on and as of
      the
      Closing Date;




(b)  Performance .
      Purchaser shall have performed and observed, in all material respects, all
      covenants and agreements to be performed or observed by it under this Agreement
      prior to or on the Closing Date;





(c)  Pending
      Litigation .
      No
      suit, action or other proceeding by a third party (including any Governmental
      Body) seeking to restrain, enjoin or otherwise prohibit the consummation of
      the
      transactions contemplated by this Agreement shall be pending before any
      Governmental Body; provided, however, Closing shall proceed notwithstanding
      any
      suits, actions or other proceedings seeking to restrain, enjoin or otherwise
      prohibit the consummation of the transactions contemplated hereby brought by
      holders of Preference Rights seeking to enforce such rights with respect to
      Assets with aggregate Allocated Values of less than ten percent (10%) of the
      unadjusted Purchase Price, and the Assets subject to such suits, actions or
      other proceedings shall be treated in accordance with **Section
      7.8** ;




(d)  Deliveries .
      Purchaser shall have delivered to Seller duly executed counterparts of the
      Conveyance and the other documents and certificates to be delivered by Purchaser
      under **Section
      9.3** ;




(e)  Title
      and Environmental Defects .
      The sum
      of (i) the adjustment to the Purchase Price on account of the sum of all Title
      Defect Amounts for Title Defects determined under **Section
      3.4(g)** prior to
      Closing, less the sum of all Title Benefit Amounts for Title Benefits determined
      under **Section
      3.4(h** )
      prior
      to the Closing, and (ii) subject to **Section
      4.3(f)** ,
      the
      amount of all Environmental Defect Amounts attributable to Environmental
      Defects, shall be less than ten percent (10%) of the unadjusted Purchase
      Price;





(f)  Casualty
      or Condemnation .
      The
      aggregate losses from casualties to the Assets and takings of Assets under
      right
      of eminent domain shall be less than ten percent (10%) of the unadjusted
      Purchase Price;




(g)  Payment .
      Purchaser shall have paid the Closing Payment; and




Page
          44 of
          65




(h)  HSR
      Act .
      Any
      waiting period applicable to the consummation of the transaction contemplated
      by
      this Agreement under the HSR Act shall have lapsed or terminated (by early
      termination or otherwise).





**Section
      8.2**  **Conditions
      of Purchaser to Closing** **.**




The
      obligations of Purchaser to consummate the transactions contemplated by this
      Agreement are subject, at the option of Purchaser, to the satisfaction on or
      prior to Closing of each of the following conditions:





(a)  Representations .
      The
      representations and warranties of Seller set forth in **Article
      5** shall be
      true and correct in all material respects, other than representations and
      warranties that are already qualified as to materiality, which shall be true
      and
      correct in all respects, as of the Closing Date as though made on and as of
      the
      Closing Date (other than representations and warranties that refer to a
      specified date which need only be true and correct on and as of such specified
      date);




(b)  Performance .
      Seller
      shall have performed and observed, in all material respects, all covenants
      and
      agreements to be performed or observed by it under this Agreement prior to
      or on
      the Closing Date;




(c)  Pending
      Litigation .
      No
      suit, action or other proceeding by a third party (including any Governmental
      Body) seeking to restrain, enjoin or otherwise prohibit the consummation of
      the
      transactions contemplated by this Agreement shall be pending before any
      Governmental Body; provided, however, Closing shall proceed notwithstanding
      any
      suits, actions or other proceedings seeking to restrain, enjoin or otherwise
      prohibit the consummation of the transactions contemplated hereby brought by
      holders of Preference Rights seeking to enforce such rights with respect to
      Assets with aggregate Allocated Values of less than ten percent (10%) of the
      unadjusted Purchase Price, and the Assets subject to such suits, actions or
      other proceedings shall be treated in accordance with **Section
      7.8** ;




(d)  Deliveries .
      Seller
      shall have delivered to Purchaser duly executed counterparts of the Conveyance
      and the other documents and certificates to be delivered by Seller under **Section
      9.2** ;





(e)  Title
      and Environmental Defects .
      The sum
      of (i) the adjustment to the Purchase Price on account of the sum of all Title
      Defect Amounts for Title Defects determined under **Section
      3.4(g)** prior to
      the Closing, less the sum of all Title Benefit Amounts for Title Benefits
      determined under **Section
      3.4(h)** prior to
      Closing, and (ii) subject to **Section
      4.3(f)** ,
      the
      amount of all Environmental Defect Amounts attributable to Environmental
      Defects, shall be less than ten percent (10%) of the unadjusted Purchase Price;




(f)  Casualty
      or Condemnation .
      The
      aggregate losses from casualties to the Assets and takings of Assets under
      right
      of eminent domain shall be less than ten percent (10%) of the unadjusted
      Purchase Price; and





(g)  HSR
      Act .
      Any
      waiting period applicable to the consummation of the transaction contemplated
      by
      this Agreement under the HSR Act shall have lapsed or terminated (by early
      termination or otherwise).




Page
          45 of
          65




**ARTICLE
      9**


**CLOSING**




**Section
      9.1**  **Time
      and Place of Closing** .




(a)  Consummation
      of the purchase and sale transaction as contemplated by this Agreement (the
      “Closing”), shall, unless otherwise agreed to in writing by Purchaser and
      Seller, take place at the offices of Fulbright & Jaworski L.L.P., 1301
      McKinney, Suite 5100, Houston, Texas, at 10:00 a.m., local time, on June 27,
      2007 or if all conditions in **Article
      8** to be
      satisfied prior to Closing have not yet been satisfied or waived, as soon
      thereafter as such conditions have been satisfied or waived, subject to the
      rights of the parties under **Article
      10** .




(b)  The
      date
      on which the Closing occurs is herein referred to as the “Closing
      Date.”




**Section
      9.2**  **Obligations
      of Seller at Closing** .




At
      the
      Closing, upon the terms and subject to the conditions of this Agreement, Seller
      shall deliver or cause to be delivered to Purchaser, the following:




(a)  the
      Conveyance, in sufficient duplicate originals to allow recording in all
      appropriate jurisdictions and offices, duly executed by Seller;




(b)  letters-in-lieu
      of transfer orders covering the Assets, duly executed by Seller;




(c)  a
      certificate duly executed by an authorized corporate officer of Seller, dated
      as
      of Closing, certifying on behalf of Seller that the conditions set forth in **Sections
      8.2(a)** and **8.2(b)** have
      been fulfilled;




(d)  one
      (1)
      original legal opinion of Seller's Associate General Counsel dated as of the
      Closing regarding the due authorization, execution, delivery and performance
      by
      Seller of this Agreement and the transactions contemplated hereby in form and
      substance reasonably satisfactory to Purchaser;




(e)  one
      (1)
      original executed statement described in Treasury Regulation §1.1445-2(b)(2)
      certifying that Seller is not a foreign person within the meaning of the
      Code;





(f)  change
      of
      operator forms designating EnerVest Operating, L.L.C. as the contract operator
      of the Seller Operated Assets on behalf of EnerVest XI-WI, duly executed by
      Seller;





(g)  a
      schedule setting forth the aggregate amount payable to owners of working
      interests, royalty interests and other interests in the Properties held in
      suspense by Seller as of the Closing Date and other relevant information
      relating therein; and





(h)  possession
      and, to the extent possible, operation of the Assets.





Page
          46 of
          65





**Section
      9.3**  **Obligations
      of Purchaser at Closing** .




At
      the
      Closing, upon the terms and subject to the conditions of this Agreement,
      Purchaser shall deliver or cause to be delivered to Seller, the
      following:




(a)  a
      wire
      transfer of the Closing Payment in same-day funds;




(b)  the
      Conveyance, duly executed by Purchaser;




(c)  letters-in-lieu
      of transfer orders covering the Assets, duly executed by Purchaser;




(d)  a
      certificate by an authorized corporate officer of Purchaser, dated as of
      Closing, certifying on behalf of Purchaser that the conditions set forth in **Sections
      8.1(a)** and **8.1(b)** have
      been fulfilled;




(e)  a
      legal
      opinion of counsel to Purchaser dated as of the Closing regarding the due
      authorization, execution, delivery and performance by Purchaser of this
      Agreement and the transactions contemplated hereby in form and substance
      reasonably satisfactory to Seller; and





(f)  change
      of
      operator forms designating EnerVest Operating, L.L.C. as the contract operator
      of the Seller Operated Assets on behalf of EnerVest XI-WI, duly executed by
      Purchaser.





**Section
      9.4**  **Closing
      Payment & Post-Closing Purchase Price Adjustments.**




(a)  Not
      later
      than three (3) Business Days prior to the Closing Date, Seller shall prepare
      and
      deliver to Purchaser, based upon the best information available to Seller,
      a
      preliminary settlement statement estimating the Adjusted Purchase Price after
      giving effect to all Purchase Price adjustments provided for in this Agreement.
      The estimate delivered in accordance with this **Section
      9.4(a)** shall
      constitute the dollar amount to be paid by Purchaser to Seller at the Closing
      (the “Closing Payment”).




Page
          47 of
          65




(b)As
      soon
      as reasonably practicable after the Closing but not later than one hundred
      and
      twenty (120) days following the Closing Date, Seller shall prepare and deliver
      to Purchaser a statement setting forth the final calculation of the Adjusted
      Purchase Price and showing the calculation of each adjustment, based, to the
      extent possible, on actual credits, charges, receipts and other items before
      and
      after the Effective Time and taking into account all adjustments provided for
      in
      this Agreement. Seller shall at Purchaser’s request supply reasonable
      documentation available to support any credit, charge, receipt or other item.
      As
      soon as reasonably practicable but not later than the 30th day following receipt
      of Seller’s statement hereunder, Purchaser shall deliver to Seller a written
      report containing any changes that Purchaser proposes be made to such Statement.
      The parties shall undertake to agree on the final statement of the Adjusted
      Purchase Price no later than one hundred eighty (180) days after the Closing
      Date. In the event that the parties cannot reach agreement within such period
      of
      time, either party may refer the remaining matters in dispute to KPMG LLP,
      or
      such other nationally-recognized independent accounting firm as may be accepted
      by Purchaser and Seller, for review and final determination. The accounting
      firm
      shall conduct the arbitration proceedings in Houston, Texas in accordance with
      the Commercial Arbitration Rules of the American Arbitration Association, to
      the
      extent such rules do not conflict with the terms of this**Section
      9.4**.
      The
      accounting firm’s determination shall be made within thirty (30) days aftersubmission of the matters in dispute and shall be final and binding
      on
      both parties, without right of appeal. In determining the proper amount of
      any
      adjustment to the Purchase Price, the accounting firm shall not increase the
      Purchase Price more than the increase proposed by Seller nor decrease the
      Purchase Price more than the decrease proposed by Purchaser, as applicable.
      The
      accounting firm shall act as an expert for the limited purpose of determining
      the specific disputed matters submitted by either party and may not award
      damages or penalties to either party with respect to any matter. Seller and
      Purchaser shall each bear its own legal fees and other costs of presenting
      its
      case. Each party shall bear one-half of the costs and expenses of the accounting
      firm. Within ten (10) Business Days after the date on which the parties or
      the
      accounting firm, as applicable, finally determines the disputed matters, (x)
      Purchaser shall pay to Seller the amount by which the Adjusted Purchase Price
      exceeds the Closing Payment or (y) Seller shall pay to Purchaser the amount
      by
      which the Closing Payment exceeds the Adjusted Purchase Price, as applicable.
      Any post-Closing payment pursuant to this **Section
      9.4(b)** shall
      bear interest at the Agreed Interest Rate from the Closing Date to the date
      both
      Purchaser and Seller have executed the final settlement statement.




(c)  All
      payments made or to be made hereunder to Seller shall be by electronic transfer
      of immediately available funds to the account of Anadarko Petroleum Corporation,
      Account No. 5762707 at JPMorgan Chase, Chicago, IL, ABA No. 021000021, for
      the
      credit of Seller or to such other bank and account as may be specified by Seller
      in writing. All payments made or to be made hereunder to Purchaser shall be
      by
      electronic transfer of immediately available funds to a bank and account
      specified by Purchaser in writing to Seller.




**ARTICLE
      10**


**TERMINATION** ****





**Section
      10.1**  **Termination** **.**




Unless
      terminated earlier pursuant to other provisions provided herein, this Agreement
      may be terminated at any time prior to Closing: (i) by the mutual prior written
      consent of Seller and Purchaser; or (ii) by Seller, if Closing has not occurred
      on or before August 1, 2007.




**Section
      10.2**  **Effect
      of Termination** **.**




If
      this
      Agreement is terminated pursuant to **Section
      10.1** ,
      this
      Agreement shall become void and of no further force or effect (except for the
      provisions of **Sections
      5.6** , **6.5** , **7.5** , **7.7** , **11.4(b)(vi)** , **11.8** , **11.9.1** , **11.9.2** , **12.7** , **12.13 and 12.16** of
      this
      Agreement all of which shall continue in full force and effect) and Seller
      shall
      be free immediately to enjoy all rights of ownership of the Assets and to sell,
      transfer, encumber or otherwise dispose of the Assets to any party without
      any
      restriction under this Agreement. Notwithstanding anything to the contrary
      in
      this Agreement, the termination of this Agreement under **Section
      10.1(ii)** shall
      not relieve any party from liability for any willful or negligent failure to
      perform or observe in any material respect any of its agreements or covenants
      contained herein which are to be performed or observed at or prior to Closing.
      In the event this Agreement terminates under **Section
      10.1(ii)** because
      a party has willfully or negligently failed to perform or observe in any
      material respect any of its agreements or covenants contained herein which
      are
      to be performed at or prior to Closing, then the other party shall be entitled
      to all remedies available at law or in equity and shall be entitled to recover
      court costs and attorneys’ fees in addition to any other relief to which such
      party may be entitled.




Page
          48 of
          65




**Section
      10.3**  **Distribution
      of Deposit Upon Termination** **.**





(a)  If
      Seller
      terminates this Agreement (i) because Purchaser has failed to comply with
      any provision of **Section
      8.1** ;
      or
      (ii) as the result of any default or breach by Purchaser of Purchaser's
      obligations hereunder, then Seller may retain the Deposit together with all
      interest accrued thereon or deemed to have accrued thereon as contemplated
      by **Section
      2.4** as
      liquidated damages, free of any claims by Purchaser or any other Person with
      respect thereto and in full and complete satisfaction of all Seller’s claims. It
      is expressly stipulated by the parties that the actual amount of damages
      resulting from such a termination would be difficult if not impossible to
      determine accurately because of the unique nature of this Agreement, the unique
      nature of the Assets, the uncertainties of applicable commodity markets and
      differences of opinion with respect to such matters, and that the liquidated
      damages provided for herein are a reasonable estimate by the parties of such
      damages.





(b)  If
      this
      Agreement is terminated for any reason other than the reasons set forth in **Section 10.3(a)** ,
      then
      Seller shall deliver the Deposit together with all interest accrued thereon
      or
      deemed to have accrued thereon as contemplated by **Section
      2.4** to
      Purchaser, free of any claims by Seller or any other Person with respect
      thereto.








**ARTICLE
      11**


**POST-CLOSING
      OBLIGATIONS; INDEMNIFICATION;**


**LIMITATIONS;
      DISCLAIMERS AND WAIVERS**




**Section
      11.1**  **Receipts** **.**




Except
      as
      otherwise provided in this Agreement, any Hydrocarbons produced from or
      attributable to the Assets (and all products and proceeds attributable thereto)
      and any other income, proceeds, receipts and credits attributable to the Assets
      which are not reflected in the adjustments to the Purchase Price following
      the
      final adjustment pursuant to **Section
      9.4(b)** shall be
      treated as follows: (a) all Hydrocarbons produced from or attributable to the
      Assets (and all products and proceeds attributable thereto) and all other
      income, proceeds, receipts and credits earned with respect to the Assets to
      which Purchaser is entitled under **Section
      1.4** shall be
      the sole property and entitlement of Purchaser, and, to the extent received
      by
      Seller, Seller shall fully disclose, account for and remit the same promptly
      to
      Purchaser, and (b) all Hydrocarbons produced from or attributable to the Assets
      (and all products and proceeds attributable thereto) and all other income,
      proceeds, receipts and credits earned with respect to the Assets to which Seller
      is entitled under **Section
      1.4** shall be
      the sole property and entitlement of Seller and, to the extent received by
      Purchaser, Purchaser shall fully disclose, account for and remit the same
      promptly to Seller.





**Section
      11.2**  **Expenses** **.**




Except
      for Royalty Amounts, any Property Costs which are not reflected in the
      adjustments to the Purchase Price following the final adjustment pursuant to **Section
      9.4(b)** shall be
      treated as follows: (a) all Property Costs for which Seller is responsible
      under **Section
      1.4** shall be
      the sole obligation of Seller and Seller shall promptly pay, or if paid by
      Purchaser, promptly reimburse Purchaser for and hold Purchaser harmless from
      and
      against same; and (b) all Property Costs for which Purchaser is responsible
      under **Section
      1.4** shall be
      the sole obligation of Purchaser and Purchaser shall promptly pay, or if paid
      by
      Seller, promptly reimburse Seller for and hold Seller harmless from and against
      same. Seller is entitled to resolve all joint interest audits and other audits
      of Property Costs covering periods for which Seller is in whole or in part
      responsible, provided that Seller shall not agree to any adjustments to
      previously assessed costs for which Purchaser is liable without the prior
      written consent of Purchaser, such consent not to be unreasonably withheld.
      Seller shall provide Purchaser with a copy of all applicable audit reports
      and
      written audit agreements received by Seller and relating to periods for which
      Purchaser is partially responsible.




Page
          49 of
          65




**Section
      11.3**  **Assumed
      Seller Obligations** **.**




Without
      limiting Purchaser’s rights to indemnity under this **Article
      11** ,
      on the
      Closing Date Purchaser shall assume and hereby agrees to fulfill, perform,
      pay
      and discharge (or cause to be fulfilled, performed, paid or discharged) all
      of
      the obligations and liabilities of Seller, known or unknown, with respect to
      the
      Assets, regardless of whether such obligations or liabilities arose prior to,
      on
      or after the Effective Time, including but not limited to obligations to (a)
      furnish makeup gas according to the terms of applicable gas sales, gathering
      or
      transportation contracts, and to satisfy all other gas balancing obligations,
      if
      any, (b) pay working interests, royalties, overriding royalties and other
      interests held in suspense, (c) properly plug and abandon any and all wells,
      including inactive wells or temporarily abandoned wells, drilled on the
      Properties or otherwise pursuant to the Assets, (d) replug any well, wellbore,
      or previously plugged well on the Properties to the extent required by
      Governmental Body, (e) dismantle, salvage and remove any equipment, structures,
      materials, platforms, flowlines, and property of whatever kind related to or
      associated with operations and activities conducted on the Properties or
      otherwise pursuant to the Assets, (f) clean up, restore and/or remediate the
      premises covered by or related to the Assets in accordance with applicable
      agreements and Laws, (g) perform all obligations applicable to or imposed on
      the
      lessee, owner, or operator under the Leases and related contracts, or as
      required by applicable Laws, and (h) except as provided in Section 11.3(iii),
      pay working interests, royalties, overriding royalties and other interests
      payable to third parties on account of production from the Assets (collectively,
      “Royalty Amounts”) (all of said obligations and liabilities, subject to the
      exclusions below, herein being referred to as the “Assumed Seller Obligations”);
      provided, however, that Purchaser does not accrue any rights or assume any
      obligations or liabilities of Seller to the extent that they are:




(i)  attributable
      to or arise out of the Excluded Assets;




(ii)  except
      for Royalty Amounts, the continuing responsibility of the Seller under **Sections
      11.1** and **11.2** or
      matters for which Seller is required to indemnify Purchaser under **Section
      11.4(c)** ;





(iii)  Royalty
      Amounts payable to third parties on account of production from the Assets prior
      to the Effective Time that (a) arise out of or are attributable to the
      litigation matters listed under items 1, 2 or 4 on **Schedule
      5.7** hereof
      or (b) are specifically identified by Purchaser and of which Purchaser provides
      Seller written notice on or before the expiration of 180 days following the
      Closing Date;





(iv)  attributable
      to or arise out of Purchaser being involuntarily joined as a party to the matter
      listed under item 3 on **Schedule
      5.7** hereof;
      or





(v)  attributable
      to or arise out of any claims for injury to or death of any individual related
      in any way to the Assets that occurred prior to the Effective Time.




Page
          50 of
          65




**Section
      11.4**  **Indemnities.**





(a)  **Definitions** .





“Claim”
      or “Claims” means, unless specifically provided otherwise, all claims
      (including, but not limited to, those for damage to property, bodily injury
      and
      death, personal injury, illness, disease, maintenance, cure, loss of parental
      and spousal consortium, wrongful death, loss of support, and wrongful
      termination of employment), damages, liabilities, losses, demands, liens,
      encumbrances, fines, penalties, causes of action of any kind (including actions
      for indirect, consequential, punitive and exemplary damages), obligations,
      costs
      (including payment of all reasonable attorneys’ fees and costs of litigation),
      judgments, interest, and awards or amounts, of any kind or character, whether
      under judicial proceedings, administrative proceedings, investigation by a
      Governmental Body or otherwise, or conditions in the premises of or attributable
      to any Person or Persons or any party or parties, breach of representation
      or
      warranty (expressed or implied), under any theory of tort, contract, breach
      of
      contract (including any Claims which arise by reason of indemnification or
      assumption of liability contained in other contracts entered into by an
      Indemnified Party hereunder), at law or in equity, under statute, or otherwise,
      arising out of, or incident to or in connection with this Agreement or the
      ownership or operation of the Assets, including but not limited to Claims which
      arise out of or are directly or indirectly connected with vessels and/or the
      ownership, possession, management, manning, maintenance, supply, operation
      (including, but not limited to, ingress, egress, loading and unloading
      operations) or navigation of any vessel.





The
      phrase **“REGARDLESS
      OF FAULT”** means **WITHOUT
      REGARD TO THE CAUSE OR CAUSES OF ANY CLAIM, INCLUDING, WITHOUT LIMITATION,
      EVEN
      THOUGH A CLAIM IS CAUSED IN WHOLE OR IN PART BY:**





**THE
      NEGLIGENCE (WHETHER SOLE, JOINT, CONCURRENT, COMPARATIVE, CONTRIBUTORY, ACTIVE
      OR PASSIVE, BUT EXCLUDING GROSS NEGLIGENCE OR WILLFUL MISCONDUCT), STRICT
      LIABILITY, OR OTHER FAULT OF PURCHASER INDEMNITEES, SELLER INDEMNITEES, INVITEES
      AND/OR THIRD PARTIES; AND/OR**





**A
      PRE-EXISTING DEFECT, WHETHER PATENT OR LATENT, OF THE PREMISES OF PURCHASER’S
      PROPERTY OR SELLER’S PROPERTY (INCLUDING WITHOUT LIMITATION THE ASSETS),
      INVITEES AND/OR THIRD PARTIES; AND/OR**





**THE
      UNSEAWORTHINESS OF ANY VESSEL OR UNAIRWORTHINESS OF ANY AIRCRAFT OF A PARTY
      WHETHER CHARTERED, OWNED, OR PROVIDED BY PURCHASER INDEMNITEES, SELLER
      INDEMNITEES, INVITEES AND/OR THIRD PARTIES.**





(b)  **Purchaser
      Indemnity Obligation** . **Subject
      only to Section 11.4(c),**  **Purchaser
      shall be responsible for and indemnify, defend, release and hold harmless Seller
      Indemnitees from and against all Claims caused by, arising out of or resulting
      from** :





(i)  the
      Assumed Seller Obligations, **REGARDLESS
      OF FAULT** ;




(ii)  the
      ownership, use or operation of the Assets after the Effective Time, **REGARDLESS
      OF FAULT** ;




Page
          51 of
          65




(iii)  Purchaser’s
      breach of any of Purchaser’s covenants or agreements contained in **Article
      7** or in **Sections
      11.1** and **11.2** , **REGARDLESS
      OF FAULT** ;




any
      breach of any representation or warranty made by Purchaser contained in **Article
      6** of
      this
      Agreement or confirmed in the certificate delivered by Purchaser at Closing
      pursuant to **Section
      9.3(d)** , **REGARDLESS
      OF FAULT** ;





(v)  Environmental
      Laws, Environmental Liabilities, the
      release of materials into the environment or protection of human health, safety,
      natural resources or the environment, or any other environmental condition
      of
      the Assets, **REGARDLESS
      OF FAULT;** and





(vi)  Purchaser
      Indemnitees’ access under **Section
      4.1** , **Section
      7.1** ,
      or
      otherwise, to the Assets, the Records and other related activities or
      information prior to the Closing, **REGARDLESS
      OF FAULT** .




(c)  **Seller
      Indemnity Obligation** . **Subject
      to the limitations contained in Section 11.7, Seller shall be responsible for
      and indemnify, defend and hold harmless Purchaser against and from all Claims
      caused by, arising out of or resulting from those obligations and liabilities
      described in Sections 11.3(i) through (v)** .





(d)  **Additional
      Provisions** .





It
      is the
      intention of the parties that this **Article
      11** shall
      govern the allocation of risks and liabilities between Purchaser and Seller
      except to the extent that it is expressly stated (whether elsewhere in this **Article
      11** or in
      some other Article hereof) that the provisions of such other Article (or part
      thereof) shall control over the terms of all or part of this **Article
      11** .





Notwithstanding
      anything to the contrary contained in this Agreement, this **Section
      11.4** contains
      the parties’ exclusive remedy against each other with respect to breaches of the
      representations, warranties, covenants and agreements of the parties contained
      in **Articles
      5, 6** and **Sections
      7.1** , **7.2** , **7.3** , **7.4** , **7.5,**  **7.6,
      11.1** and **11.2** and the
      affirmations of such representations, warranties, covenants and agreements
      contained in the certificate delivered by each party at Closing pursuant to **Sections
      9.2(c)** or **9.3(d)** ,
      as
      applicable.




In
      connection with Purchaser Indemnitees’ access to the Assets prior to Closing,
      the parties acknowledge that such access may be subject to boarding agreements,
      releases or other agreements required by Seller or the operator of Non-Operated
      Assets. In the event of a conflict between the provisions of such agreements
      and **Section
      11.4(b)(vi)** of
      this
      Agreement, **Section
      11.4(b)(vi)** of this
      Agreement shall control.





**Section
      11.5**  **Indemnification
      Actions** **.**




All
      claims for indemnification under **Section
      11.4** shall be
      asserted and resolved as follows:




(a)  For
      purposes of this **Article
      11** ,
      the
      term “Indemnifying Party” shall mean the party or parties having an obligation
      to indemnify another party or parties pursuant to the terms of this Agreement.
      The term “Indemnified Party” shall mean the party or parties having the right to
      be indemnified by another party or parties pursuant to the terms of this
      Agreement.




Page
          52 of
          65




(b)  To
      make a
      claim for indemnification (“Indemnity Claim”) under **Section
      11.4** ,
      and/or
      any other Article (or part thereof) expressly stating that it controls over
      the
      terms of this **Article
      11** ,
      an
      Indemnified Party shall notify the Indemnifying Party in writing of its
      Indemnity Claim, including the specific details of and specific basis under
      this
      Agreement for its Indemnity Claim (the “Claim Notice”). The Indemnified Party
      shall provide its Claim Notice promptly after the Indemnified Party has actual
      knowledge of the Claim for which it seeks indemnification and shall enclose
      a
      copy of all papers (if any) served with respect to the Claim; provided that
      the
      failure of any Indemnified Party to give notice of a Claim as provided in this **Section
      11.5** shall
      not relieve the Indemnifying Party of its obligations under **Section
      11.4** except
      to the extent such failure results in insufficient time being available to
      permit the Indemnifying Party to effectively defend against the Claim or
      otherwise prejudices the Indemnifying Party’s ability to defend against the
      Claim. In the event that the Indemnity Claim is based upon an inaccuracy or
      breach of a representation, warranty, covenant or agreement, the Claim Notice
      shall specify the representation, warranty, covenant or agreement which was
      inaccurate or breached.




(c)  The
      Indemnifying Party shall have thirty (30) days from its receipt of the Claim
      Notice to notify the Indemnified Party whether it admits or denies its liability
      to defend the Indemnified Party against the relevant Claim at the sole cost
      and
      expense of the Indemnifying Party. The Indemnified Party is authorized, prior
      to
      and during such 30-day period, to file any motion, answer or other pleading
      that
      it shall deem necessary or appropriate to protect its interests or those of
      the
      Indemnifying Party and that is not prejudicial to the Indemnifying
      Party.





(d)  If
      the
      Indemnifying Party admits its liability to indemnify the Indemnified Party,
      it
      shall have the right and obligation to diligently defend, at its sole cost
      and
      expense, the Claim. The Indemnifying Party shall have full control of such
      defense and proceedings, including any compromise or settlement thereof. If
      requested by the Indemnifying Party, the Indemnified Party agrees to cooperate
      in contesting any Claim which the Indemnifying Party elects to contest. The
      Indemnified Party may participate in, but not control, any defense or settlement
      of any Claim controlled by the Indemnifying Party pursuant to this **Section
      11.5(d)** .
      An
      Indemnifying Party shall not, without the written consent of the Indemnified
      Party, (i) settle any Claim or consent to the entry of any judgment with respect
      thereto which does not include an unconditional written release of the
      Indemnified Party from all liability in respect of such Claim, or (ii) settle
      any Claim or consent to the entry of any judgment with respect thereto in any
      manner that may materially and adversely affect the Indemnified Party (other
      than as a result of money damages covered by the indemnity).




(e)  If
      the
      Indemnifying Party does not admit its liability to indemnify the Indemnified
      Party or admits its liability but fails to diligently prosecute or settle the
      Claim, then the Indemnified Party shall have the right to defend against the
      Claim at the sole cost and expense of the Indemnifying Party, with counsel
      of
      the Indemnified Party’s choosing, subject to the right of the Indemnifying Party
      to admit its liability and assume the defense of the Claim at any time prior
      to
      settlement or final determination thereof. If the Indemnifying Party has not
      yet
      admitted its liability for a Claim, the Indemnified Party shall send written
      notice to the Indemnifying Party of any proposed settlement and the Indemnifying
      Party shall have the option for ten (10) Business Days following receipt of
      such
      notice to (i) admit in writing its liability to indemnify the Indemnified Party
      from and against the Claim and (ii) if liability is so admitted, reject, in
      its
      reasonable judgment, the proposed settlement.




Page
          53 of
          65




**Section
      11.6**  **Release.**





(a)  **PURCHASER
      RELEASES, REMISES AND FOREVER DISCHARGES SELLER INDEMNITEES FROM ANY AND ALL
      CLAIMS, KNOWN OR UNKNOWN,** **WHETHER
      NOW EXISTING OR ARISING IN THE FUTURE, CONTINGENT OR
      OTHERWISE,** **WHICH PURCHASER MIGHT NOW OR SUBSEQUENTLY MAY HAVE AGAINST SELLER INDEMNITEES,
      RELATING DIRECTLY OR INDIRECTLY TO THE ASSETS, THIS AGREEMENT, INCLUDING WITHOUT
      LIMITATION CLAIMS ARISING OUT OF OR INCIDENT TO** **ENVIRONMENTAL
      LAWS, ENVIRONMENTAL LIABILITIES, THE RELEASE OF MATERIALS INTO THE ENVIRONMENT
      OR PROTECTION OF HUMAN HEALTH, SAFETY, NATURAL RESOURCES OR THE
      ENVIRONMENT,** **INCLUDING, WITHOUT LIMITATION, RIGHTS TO CONTRIBUTION UNDER THE COMPREHENSIVE
      ENVIRONMENTAL RESPONSE, COMPENSATION, AND LIABILITY ACT OF 1980, AS AMENDED,
      REGARDLESS OF FAULT.**





(b)  Purchaser
      covenants and agrees that it will not attempt to avoid the effect of the release
      made by it hereinabove by later arguing that at the time of the release it
      did
      not fully appreciate the extent of any such Claims, including without
      limitation, environmental Claims.




**Section
      11.7**  **Limitation
      on Actions.**




(a)  The
      representations and warranties of the parties in **Articles
      5** and **6** terminate
      upon Closing, **except
      that**  **Section
      6.11** shall
      survive indefinitely. The remainder of the representations, warranties,
      covenants and agreements provided for in this Agreement shall not survive
      Closing except that covenants and agreements contemplated to be complied with
      or
      performed following the Closing shall survive indefinitely. Representations,
      warranties, covenants and agreements shall be of no further force and effect
      after the date of their expiration, provided that there shall be no termination
      of any bona fide Claim asserted pursuant to this Agreement with respect to
      the
      breach of such a representation, warranty, covenant or agreement on or before
      its expiration date.




(b)  The
      indemnities in **Sections
      11.4(b)(iii)** and **11.4(b)(iv)** shall
      terminate as of the termination date of each respective representation,
      warranty, covenant or agreement that is subject to indemnification, except
      in
      each case as to Claims asserted pursuant to this Agreement with respect to
      the
      breach of such representation, warranty, covenant or agreement on or before
      such
      termination date. Purchaser’s indemnities in **Sections
      11.4(b)(i)** , **11.4(b)(ii)** , **11.4(b)(v)** ,
      and **11.4(b)(vi)** and
      Seller’s indemnity in **Section
      11.4(c)** shall
      continue without time limit; provided, however, Seller’s obligation to indemnify
      Purchaser for those obligations and liabilities described in **Section
      11.3(iii)** shall
      terminate 180 days following the Closing Date.




(c)  **[RESERVED]**




(d)  Notwithstanding
      anything to the contrary contained elsewhere in this Agreement, Seller shall
      not
      be required to indemnify Purchaser for aggregate damages in excess of an amount
      equal to twenty-five percent (25%) of the final Adjusted Purchase Price;
      provided, however, that the limitation set forth in this **Section
      11.7 (d** )
      shall
      not apply to Seller’s indemnity obligation relating to the Excluded Assets
      .




Page
          54 of
          65




**Section
      11.8**  **Disclaimers** **.**





**(a)**  **EXCEPT
      AS AND TO THE EXTENT EXPRESSLY SET FORTH IN ARTICLE 5 OF THIS AGREEMENT, OR
      CONFIRMED IN THE CERTIFICATE OF SELLER TO BE DELIVERED PURSUANT TO SECTION
      9.2(c), OR IN THE CONVEYANCE, (I) SELLER MAKES NO REPRESENTATIONS OR WARRANTIES,
      EXPRESS, STATUTORY OR IMPLIED, AND (II) SELLER EXPRESSLY DISCLAIMS ALL LIABILITY
      AND RESPONSIBILITY FOR ANY REPRESENTATION, WARRANTY, STATEMENT OR INFORMATION
      MADE OR COMMUNICATED (ORALLY OR IN WRITING) TO PURCHASER OR ANY OF ITS
      AFFILIATES, EMPLOYEES, AGENTS, CONSULTANTS OR REPRESENTATIVES (INCLUDING,
      WITHOUT LIMITATION, ANY OPINION, INFORMATION, PROJECTION OR ADVICE THAT MAY
      HAVE
      BEEN PROVIDED TO PURCHASER BY ANY OFFICER, DIRECTOR, EMPLOYEE, AGENT,
      CONSULTANT, REPRESENTATIVE OR ADVISOR OF SELLER OR ANY OF ITS
      AFFILIATES).**




**(b)**  **EXCEPT
      AS EXPRESSLY REPRESENTED OTHERWISE IN ARTICLE 5 OF THIS AGREEMENT, OR CONFIRMED
      IN THE CERTIFICATE OF SELLER TO BE DELIVERED PURSUANT TO SECTION 9.2(c), OR
      IN
      THE CONVEYANCE, AND WITHOUT LIMITING THE GENERALITY OF THE FOREGOING, SELLER
      EXPRESSLY DISCLAIMS ANY REPRESENTATION OR WARRANTY, EXPRESS, STATUTORY OR
      IMPLIED, AS TO (I) TITLE TO ANY OF THE ASSETS, (II) THE CONTENTS, CHARACTER
      OR
      NATURE OF ANY DESCRIPTIVE MEMORANDUM, OR ANY REPORT OF ANY PETROLEUM ENGINEERING
      CONSULTANT, OR ANY GEOLOGICAL OR SEISMIC DATA OR INTERPRETATION, RELATING TO
      THE
      ASSETS, (III) THE QUANTITY, QUALITY OR RECOVERABILITY OF PETROLEUM SUBSTANCES
      IN
      OR FROM THE ASSETS, (IV) ANY ESTIMATES OF THE VALUE OF THE ASSETS OR FUTURE
      REVENUES GENERATED BY THE ASSETS, (V) THE PRODUCTION OF HYDROCARBONS FROM THE
      ASSETS, (VI) THE MAINTENANCE, REPAIR, CONDITION, QUALITY, SUITABILITY, DESIGN
      OR
      MARKETABILITY OF THE ASSETS, (VII) THE CONTENT, CHARACTER OR NATURE OF ANY
      DESCRIPTIVE MEMORANDUM, REPORTS, BROCHURES, CHARTS OR STATEMENTS PREPARED BY
      THIRD PARTIES, (VIII) ANY OTHER MATERIALS OR INFORMATION THAT MAY HAVE BEEN
      MADE
      AVAILABLE OR COMMUNICATED TO PURCHASER OR ITS AFFILIATES, OR ITS OR THEIR
      EMPLOYEES, AGENTS, CONSULTANTS, REPRESENTATIVES OR ADVISORS IN CONNECTION WITH
      THE TRANSACTIONS CONTEMPLATED BY THIS AGREEMENT OR ANY DISCUSSION OR
      PRESENTATION RELATING THERETO, AND FURTHER DISCLAIMS ANY REPRESENTATION OR
      WARRANTY, EXPRESS, STATUTORY OR IMPLIED, OF MERCHANTABILITY, FREEDOM FROM
      REDHIBITORY VICES OR DEFECTS (INCLUDING THOSE CONTEMPLATED IN LOUISIANA CIVIL
      CODE ARTICLES 2475, AND 2520 THROUGH 2548), FITNESS FOR A PARTICULAR PURPOSE
      OR
      CONFORMITY TO MODELS OR SAMPLES OF MATERIALS OF ANY EQUIPMENT, IT BEING
      EXPRESSLY UNDERSTOOD AND AGREED BY THE PARTIES HERETO THAT PURCHASER SHALL
      BE
      DEEMED TO BE OBTAINING THE ASSETS IN THEIR PRESENT STATUS, CONDITION AND STATE
      OF REPAIR, “AS IS” AND “WHERE IS” WITH ALL FAULTS AND THAT PURCHASER HAS MADE OR
      CAUSED TO BE MADE SUCH INSPECTIONS AS PURCHASER DEEMS APPROPRIATE, OR (IX)
      ANY
      IMPLIED OR EXPRESS WARRANTY OF FREEDOM FROM PATENT OR TRADEMARK
      INFRINGEMENT.**





**(c)**  **SELLER
      HAS NOT AND WILL NOT MAKE ANY REPRESENTATION OR WARRANTY REGARDING ANY MATTER
      OR
      CIRCUMSTANCE RELATING TO ENVIRONMENTAL LAWS, ENVIRONMENTAL LIABILITIES, THE
      RELEASE OF MATERIALS INTO THE ENVIRONMENT OR THE PROTECTION OF HUMAN HEALTH,
      SAFETY, NATURAL RESOURCES OR THE ENVIRONMENT, OR ANY OTHER ENVIRONMENTAL
      CONDITION OF THE ASSETS, AND NOTHING IN THIS AGREEMENT OR OTHERWISE SHALL BE
      CONSTRUED AS SUCH A REPRESENTATION OR WARRANTY, AND PURCHASER SHALL BE DEEMED
      TO
      BE TAKING THE ASSETS “AS IS” AND “WHERE IS” FOR PURPOSES OF THEIR ENVIRONMENTAL
      CONDITION.**




Page
          55 of
          65




**Section
      11.9**  **Waivers.**





**Section
      11.9.1**  **Waiver
      of Trade Practices Acts.**





(a)  It
      is the
      intention of the parties that Purchaser's rights and remedies with respect
      to
      this transaction and with respect to all acts or practices of Seller, past,
      present or future, in connection with this transaction shall be governed by
      legal principles other than the Texas Deceptive Trade Practices--Consumer
      Protection Act, Tex. Bus. & Com. Code Ann. § 17.41 *et
      seq* .
      (the
      "DTPA") or the Louisiana unfair trade practices and consumer protection law,
      La.
      R.S. 51:1402, *et
      seq* .
      (the
“UTPCPL”). As such, Purchaser hereby waives the applicability of the DTPA and
      the UTPCPL to this transaction and any and all duties, rights or remedies that
      might be imposed by the DTPA and/or the UTPCPL, whether such duties, rights
      and
      remedies are applied directly by the DTPA or the UTPCPL itself or indirectly
      in
      connection with other statutes; *provided,
      however* ,
      Purchaser does not waive § 17.555 of the DTPA. Purchaser acknowledges,
      represents and warrants that it is purchasing the goods and/or services covered
      by this Agreement for commercial or business use; that it has assets of $5
      million or more according to its most recent financial statement prepared in
      accordance with generally accepted accounting principles; that it has knowledge
      and experience in financial and business matters that enable it to evaluate
      the
      merits and risks of a transaction such as this; and that it is not in a
      significantly disparate bargaining position with Seller.





(b)  Purchaser
      expressly recognizes that the price for which Seller has agreed to perform
      its
      obligations under this Agreement has been predicated upon the inapplicability
      of
      the DTPA and the UTPCPL and this waiver of the DTPA and the UTPCPL. Purchaser
      further recognizes that Seller, in determining to proceed with the entering
      into
      of this Agreement, has expressly relied on this waiver and the inapplicability
      of the DTPA and the UTPCPL.




**Section
      11.9.2**  **Redhibition
      Waiver.**





Purchaser
      waives all rights in redhibition pursuant to Louisiana Civil Code Articles
      2475
      and 2520 through 2548, and acknowledges that this express waiver shall be
      considered a material and integral part of this sale and the consideration
      thereof. Purchaser acknowledges that this waiver has been brought to its
      attention and has been explained in detail and that Purchaser has voluntarily
      and knowingly consented to this waiver of warranty of fitness and warranty
      against redhibitory vices and defects for the Assets.





**Section
      11.10**  **Recording.**




As
      soon
      as practicable after Closing, Purchaser shall record the Conveyance in the
      appropriate counties and/or parishes and provide Seller with copies of all
      recorded or approved instruments.





The
      conveyance in the form attached as **Exhibit
      B** is
      intended to convey all of the Properties being conveyed pursuant to this
      Agreement. Certain Properties or specific portions of the Properties that are
      leased from, or require the approval to transfer by, a governmental entity
      are
      conveyed under the Conveyance and also are described and covered other separate
      assignments made by Seller to Purchaser on officially approved forms, or forms
      acceptable to such entity, in sufficient multiple originals to satisfy
      applicable statutory and regulatory requirements. **The
      interests conveyed by such separate assignments are the same, and not in
      addition to, the interests conveyed in the Conveyance attached as Exhibit B.
      Further, such assignments shall be deemed to contain the special warranty of
      title of Seller and all of the exceptions, reservations, rights, titles, power
      and privileges set forth herein and in the Conveyance as fully and only to
      the
      extent as though they were set forth in each such separate
      assignment.**




Page
          56 of
          65




**ARTICLE
      12**


**MISCELLANEOUS**




**Section
      12.1**  **Counterparts** **.**




This
      Agreement may be executed in counterparts, each of which shall be deemed an
      original instrument, but all such counterparts together shall constitute but
      one
      agreement.





**Section
      12.2**  **Notice** **.**




All
      notices which are required or may be given pursuant to this Agreement shall
      be
      sufficient in all respects if given in writing and delivered personally, by
      telecopy or by registered or certified mail, postage prepaid, as
      follows:


If to Seller:
              Anadarko
                  E&P Company LPKerr-McGee
                  Oil & Gas Onshore LP1201
                  Lake Robbins DriveThe
                  Woodlands, TX 77380Attention: 
                  Transactions Manager, Business DevelopmentTelephone:  
                  (832) 636-3088Telecopy:    
                  (832) 636-8059With a copy to:
              Anadarko
                  E&P Company LPKerr-McGee
                  Oil & Gas Onshore LP1201
                  Lake Robbins DriveThe
                  Woodlands, TX 77380Attention:       
                  Associate General CounselOil, Gas and MineralsTelephone: 
                  (832) 636-7530Telecopy:    (832)
                  636-5889If to Purchaser:
              EnerVest
                  Energy Institutional Fund X-A, L.P.1001
                  Fannin, Suite 800Houston,
                  TX 77002Attention:
                  Mr. Mark A. HouserTelephone: 
                  (713) 659-3500Telecopy: 
                  (713) 659-3556




Page
          57 of
          65




EnerVest
                  Energy Institutional Fund X-WI, L.P.1001
                  Fannin, Suite 800Houston,
                  TX 77002Attention:
                  Mr. Mark A. HouserTelephone:
                  (713) 659-3500Telecopy:
                  (713) 659-3556EnerVest
                  Energy Institutional Fund XI-A, L.P.1001
                  Fannin, Suite 800Houston,
                  TX 77002Attention:
                  Mr. Mark A. HouserTelephone:
                  (713) 659-3500Telecopy:
                  (713) 659-3556EnerVest
                  Energy Institutional Fund XI-WI, L.P.1001
                  Fannin, Suite 800Houston,
                  TX 77002Attention:
                  Mr. Mark A. HouserTelephone:
                  (713) 659-3500Telecopy:
                  (713) 659-3556Wachovia
                  Investment Holdings, LLCc/o
                  Wachovia SecuritiesStructured
                  Asset Finance301
                  South College StreetNC0174Charlotte,
                  North Carolina 28288Attention:
                  Mr. Robert ChristensenTelephone:
                  (704) 383-9688Telecopy:
                  (704) 383-4012EnerVest
                  Management Partners, Ltd.1001
                  Fannin, Suite 800Houston,
                  TX 77002Attention:
                  Mr. Mark A. HouserTelephone:
                  (713) 659-3500Telecopy:
                  (713) 659-3556EV
                  Properties, L.P..1001
                  Fannin, Suite 800Houston,
                  TX 77002Attention:
                  Mr. Michael MercerTelephone:
                  (713) 659-3500Telecopy:
                  (713) 659-3556




Page
          58 of
          65


With
                  a copy to:
              Haynes
                  and Boone LLP1221
                  McKinney, Suite 2100Houston,
                  TX 77010Attention:
                  Fabené J. WelchTelephone:
                  (713) 547-2004Telecopy:
                  (713) 236-5578




Either
      party may change its address for notice by notice to the other in the manner
      set
      forth above. All notices shall be deemed to have been duly given at the time
      of
      receipt by the party to which such notice is addressed.




**Section
      12.3**  **Sales
      or Use Tax Recording Fees and Similar Taxes and Fees** **.**




Purchaser
      shall bear any sales, use, excise, real property transfer or gain, gross
      receipts, goods and services, registration, capital, documentary, stamp or
      transfer Taxes, recording fees and similar Taxes and fees incurred and imposed
      upon, or with respect to, the property transfers or other transactions
      contemplated hereby. Seller will determine, and Purchaser agrees to cooperate
      with Seller in determining, sales tax, if any, that is due in connection with
      the sale of Assets and Purchaser agrees to pay any such tax to Seller at
      Closing. If such transfers or transactions are exempt from any such taxes or
      fees upon the filing of an appropriate certificate or other evidence of
      exemption, Purchaser will timely furnish to Seller such certificate or
      evidence.




**Section
      12.4**  **Expenses** **.**




Except
      as
      provided in **Section
      12.3** ,
      all
      expenses incurred by Seller in connection with or related to the authorization,
      preparation or execution of this Agreement, the Conveyance delivered hereunder
      and the Exhibits and Schedules hereto and thereto, and all other matters related
      to the Closing, including without limitation, all fees and expenses of counsel,
      accountants and financial advisers employed by Seller, shall be borne solely
      and
      entirely by Seller, and all such expenses incurred by Purchaser shall be borne
      solely and entirely by Purchaser.




**Section
      12.5**  **Change
      of Name** **.**




As
      promptly as practicable, but in any case within thirty (30) days after the
      Closing Date, Purchaser shall eliminate the names “Anadarko Petroleum
      Corporation”, “Anadarko” and any variants thereof from the Assets acquired
      pursuant to this Agreement and, except with respect to such grace period for
      eliminating existing usage, shall have no right to use any logos, trademarks
      or
      trade names belonging to Seller or any of its Affiliates.




**Section
      12.6**  **Replacement
      of Bonds, Letters of Credit and Guarantees** **.**




The
      parties understand that none of the bonds, letters of credit and guarantees,
      if
      any, posted by Seller with Governmental Bodies and relating to the Assets may
      be
      transferable to Purchaser. Promptly following Closing, Purchaser shall obtain,
      or cause to be obtained in the name of Purchaser, replacements for such bonds,
      letters of credit and guarantees, to the extent such replacements are necessary
      to permit the cancellation of the bonds, letters of credit and guarantees posted
      by Seller or to consummate the transactions contemplated by this
      Agreement.




Page
          59 of
          65




**Section
      12.7**  **Governing
      Law and Venue** **.**




THIS
      AGREEMENT AND THE LEGAL RELATIONS BETWEEN THE PARTIES SHALL BE GOVERNED BY
      AND
      CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF TEXAS WITHOUT REGARD
      TO
      PRINCIPLES OF CONFLICTS OF LAWS OTHERWISE APPLICABLE TO SUCH DETERMINATIONS.
      JURISDICTION AND VENUE WITH RESPECT TO ANY DISPUTES ARISING HEREUNDER SHALL
      BE
      PROPER ONLY IN HARRIS COUNTY, TEXAS.




**Section
      12.8**  **Captions** **.**




The
      captions in this Agreement are for convenience only and shall not be considered
      a part of or affect the construction or interpretation of any provision of
      this
      Agreement.





**Section
      12.9**  **Waivers** **.**




Any
      failure by any party or parties to comply with any of its or their obligations,
      agreements or conditions herein contained may be waived in writing, but not
      in
      any other manner, by the party or parties to whom such compliance is owed.
      No
      waiver of, or consent to a change in, any of the provisions of this Agreement
      shall be deemed or shall constitute a waiver of, or consent to a change in,
      other provisions hereof (whether or not similar), nor shall such waiver
      constitute a continuing waiver unless otherwise expressly provided.




**Section
      12.10**  **Assignment** **.**




No
      party
      shall assign all or any part of this Agreement, nor shall any party assign
      or
      delegate any of its rights or duties hereunder, without the prior written
      consent of the other party and any assignment or delegation made without such
      consent shall be void. Notwithstanding the foregoing sentence, EnerVest and
      Wachovia shall each be entitled to assign all (but not less than all) of their
      respective rights, benefits, duties and obligations hereunder at any time prior
      to Closing to an entity to be formed by each of them which will be an Affiliate;
      provided, however, that in the event of such an assignment, EnerVest shall
      remain obligated to Seller under this Agreement for its Purchaser Share and
      the
      Purchaser Share of Wachovia. This Agreement shall be binding upon and inure
      to
      the benefit of the parties hereto and their respective successors and permitted
      assigns.




**Section
      12.11**  **Entire
      Agreement** **.**




The
      Confidentiality Agreement, this Agreement and the Exhibits and Schedules
      attached hereto, and the documents to be executed hereunder constitute the
      entire agreement between the parties pertaining to the subject matter hereof,
      and supersede all prior agreements, understandings, negotiations and
      discussions, whether oral or written, of the parties pertaining to the subject
      matter hereof.




**Section
      12.12**  **Amendment** .




(a)  This
      Agreement may be amended or modified only by an agreement in writing executed
      by
      both parties.




(b)  No
      waiver
      of any right under this Agreement shall be binding unless executed in writing
      by
      the party to be bound thereby.




Page
          60 of
          65




**Section
      12.13**  **No
      Third-Party Beneficiaries** .




Nothing
      in this Agreement shall entitle any Person other than Purchaser and Seller
      to
      any Claims, remedy or right of any kind, except as to those rights expressly
      provided to Seller Indemnitees and Purchaser Indemnitees (provided, however,
      any
      claim for indemnity hereunder on behalf of a Seller Indemnitee or a Purchaser
      Indemnitee must be made and administered by a party to this Agreement or their
      permitted successors and assigns).




**Section
      12.14**  **References** **.**




In
      this
      Agreement:




(a)  References
      to any gender includes a reference to all other genders;




(b)  References
      to the singular includes the plural, and vice versa;





(c)  Reference
      to any Article or Section means an Article or Section of this Agreement;




(d)  Reference
      to any Exhibit or Schedule means an Exhibit or Schedule to this Agreement,
      all
      of which are incorporated into and made a part of this Agreement;





(e)  Unless
      expressly provided to the contrary, “hereunder”, “hereof’, “herein” and words of
      similar import are references to this Agreement as a whole and not any
      particular Section or other provision of this Agreement; and




(f)  “Include”
      and “including” shall mean include or including without limiting the generality
      of the description preceding such term.




**Section
      12.15**  **Construction** .




Purchaser
      is a party capable of making such investigation, inspection, review and
      evaluation of the Assets as a prudent purchaser would deem appropriate under
      the
      circumstances including with respect to all matters relating to the Assets,
      their value, operation and suitability. Each of Seller and Purchaser has had
      substantial input into the drafting and preparation of this Agreement and has
      had the opportunity to exercise business discretion in relation to the
      negotiation of the details of the transactions contemplated hereby. This
      Agreement is the result of arm’s-length negotiations from equal bargaining
      positions. In the event of a dispute over the meaning or application of this
      Agreement, it shall be construed fairly and reasonably and neither more strongly
      for nor against either party.




**Section
      12.16**  **Limitation
      on Damages**




Notwithstanding
      any other provision contained elsewhere in this Agreement to the contrary,
      the
      parties acknowledge that this Agreement does not authorize one party to sue
      for
      or collect from the other party its own punitive damages, or its own
      consequential or indirect damages in connection with this Agreement and the
      transactions contemplated hereby and each party expressly waives for itself
      and
      on behalf of its Affiliates, any and all Claims it may have against the other
      party for its own such damages in connection with this Agreement and the
      transactions contemplated hereby.




Page
          61 of
          65




**Section
      12.17**  **Conspicuousness** .





The
      parties agree that provisions in this Agreement in "bold" type satisfy any
      requirements of the "express negligence rule" and any other requirements at
      law
      or in equity that provisions be conspicuously marked or
      highlighted.





**Section
      12.18**  **Severability** .





If
      any
      term or other provisions of this Agreement is held invalid, illegal or incapable
      of being enforced under any rule of law, all other conditions and provisions
      of
      this Agreement shall nevertheless remain in full force and effect so long as
      the
      economic or legal substance of the transactions contemplated hereby is not
      affected in a materially adverse manner with respect to either
      party.





**Section
      12.19**  **Time
      of Essence** .





Time
      is
      of the essence in this Agreement. If the date specified in this Agreement for
      giving any notice or taking any action is not a Business Day (or if the period
      during which any notice is required to be given or any action taken expires
      on a
      date which is not a Business Day), then the date for giving such notice or
      taking such action (and the expiration date of such period during which notice
      is required to be given or action taken) shall be the next day which is a
      Business Day.





[SIGNATURES
      BEGIN ON THE FOLLOWING PAGE]




Page
          62 of
          65




IN
      WITNESS WHEREOF, this Agreement has been signed by each of the parties hereto
      on
      the date first above written.




**SELLER:**
              **PURCHASER:****ANADARKO
                  E&P COMPANY LP**
              **ENERVEST
                  ENERGY INSTITUTIONAL FUND X-A, L.P.**/s/ Albert L.
                  Richey
              By:    
                  EnerVest Management Partners,By:
                  Albert L. Richey
              Ltd., its General PartnerTitle:
                  Vice President, Corporate DevelopmentBy:    
                  EnerVest Management GP, L.C., its General Partner**KERR-McGEE
                  OIL & GAS ONSHORE LP**By:/s/
                  John B.
                  Walker
                John
                  B. Walker
                President and Chief Executive Officer/s/
                  Albert L.
                  RicheyBy:
                  Albert L. RicheyTitle:
                  Vice President**ENERVEST
                  ENERGY INSTITUTIONAL FUND X-WI, L.P.**By:    
                  EnerVest Management Partners, Ltd., its General PartnerBy:    
                  EnerVest Management GP, L.C., its General PartnerBy:/s/
                  John B.
                  Walker
                John B. Walker
                President and Chief Executive
                  Officer


Page
          63 of
          65




**ENERVEST
                  ENERGY INSTITUTIONAL FUND XI-A, L.P.**By:    
                  EnerVest Management Partners, Ltd., its General PartnerBy:    
                  EnerVest Management GP, L.C., its General PartnerBy:/s/
                  John B.
                  WalkerJohn B. WalkerPresident and Chief Executive Officer**ENERVEST
                  ENERGY INSTITUTIONAL FUND XI-WI, LTD.**By:    
                  EnerVest Management Partners, Ltd., its General PartnerBy:    
                  EnerVest Management GP, L.C., its General PartnerBy:/s/
                  John B.
                  WalkerJohn B. WalkerPresident and Chief Executive Officer**ENERVEST
                  MANAGEMENT PARTNERS, LTD**By:    
                  EnerVest Management GP, L.P.its General PartnerBy:/s/
                  John B.
                  WalkerJohn B. WalkerPresident and Chief Executive
                  Officer





Page
          64 of
          65




**WACHOVIA
                  INVESTMENT HOLDINGS, LLC**By:/s/
                  Ken
                  CarpenterKen CarpenterManaging Director**EV
                  PROPERTIES, L.P.**By:    
                  EV Properties GP, LLC, its General PartnerBy:    
                  EV Energy Partners, L.P., its Sole MemberBy:    
                  EV Energy GP, L.P., its General PartnerBy:    
                  EnerVest Management, LLC, its General PartnerBy:/s/
                  John B.
                  WalkerJohn B. WalkerPresident and Chief Executive
                  Officer






Page
          65 of
          65