<PAGE>
 
EXHIBIT 4.3

                      CERTIFICATE OF OWNERSHIP AND MERGER
                                      OF
                         GERRITY OIL & GAS CORPORATION
                                 WITH AND INTO
                         PATINA OIL & GAS CORPORATION

                        (Pursuant to Section 253 of the
               General Corporation Law of the State of Delaware)


     Patina Oil & Gas Corporation, a Delaware corporation (the "Corporation"),
for the purpose of merging Gerrity Oil & Gas Corporation, a Delaware corporation
(the "Subsidiarie"), with and into the Corporation, hereby certifies as follows:

          FIRST:  The name and the state of incorporation of each of the
     constituent corporations of the merger is as follows:

                                                      STATE OF
               NAME                                INCORPORATION
               ----                                -------------

          Patina Oil & Gas Corporation                Delaware
          Gerrity Oil & Gas Corporation               Delaware

          SECOND:  The Corporation owns all of the issued and outstanding
     capital stock of the Subsidiary.

          THIRD:  Attached hereto as Exhibit A is a true and correct copy of the
     resolutions adopted on March 20, 1997, by the Board of Directors of the
     Corporation approving the merger of the Subsidiary with and into the
     Corporation.

     IN WITNESS WHEREOF, the Corporation has caused this Certificate to be
signed by its officer thereunto duly authorized on the 21st day of March, 1997.

                              PATINA OIL & GAS CORPORATION



                              By:  /s/ Brian J. Cree
                                   ------------------------------
                                   Brian J. Cree,
                                   Executive Vice President and
                                   Chief Operating Officer
<PAGE>
 
                                   EXHIBIT A
                                   ---------

                                      NOTE


$_______________                 Houston, Texas                    April 1, 1997


     FOR VALUE RECEIVED, the undersigned, Patina Oil & Gas Corporation, a
Delaware corporation ("Maker"), promises to pay to the order of [Name of Bank or
                       -----                                     ---------------
Lending Office] ("Payee"), at the offices of Texas Commerce Bank National
--------------    -----                                                  
Association, as Administrative Agent (herein so called), at 1111 Fannin, 9th
Floor, Houston, Texas 77002, for Payee and the other Banks hereinafter
described, the principal sum of [Amount of such Bank's Commitment]
                                ----------------------------------
($___________), or so much thereof as may be advanced and outstanding, together
with interest, as hereinafter described.

     This Note has been executed and delivered pursuant to, and is subject to
and governed by, the terms of that certain Amended and Restated Credit Agreement
dated effective as of April 1, 1997 (as hereafter renewed, extended, amended, or
supplemented, the "Agreement") among Maker, Payee, Administrative Agent,
                   ---------                                            
NationsBank of Texas, N.A., as Documentary Agent, Wells Fargo Bank, N.A., CIBC,
Inc. and Credit Lyonnais New York Branch, as Co-Agents, and the other Banks
named therein and is one of the "Notes" referred to therein.  Unless otherwise
                                 -----                                        
defined herein or unless the context hereof otherwise requires, each term used
herein with its initial letter capitalized has the meaning given to such term in
the Agreement.

     Maker also promises to pay interest on the unpaid principal amount hereof
in like money at the offices of Administrative Agent above referenced from the
date hereof at the rates applicable to amounts outstanding under the Loan
provided in the Agreement.

     Accrued interest shall be due and payable on the expiration of each
Interest Period with respect to any part of the principal outstanding hereunder
which is subject to a Eurodollar Tranche with an Interest Period then expiring.
The principal balance of this Note shall be paid at the times and in the amounts
required by the Agreement.  The entire outstanding principal balance hereof and
all accrued but unpaid interest thereon shall be due and payable in full on the
Termination Date.

     Upon and subject to the terms and conditions of the Agreement, Maker shall
be entitled to prepay the principal of or interest on this Note from time to
time and at any time, in whole or in part.

     Upon the occurrence and continuance of an Event of Default, and upon the
conditions stated in the Agreement, Administrative Agent may, at its option, and
shall, to the extent required in accordance with the terms of the Agreement,
declare the entire unpaid principal of and accrued interest on this Note
immediately due and payable (provided that, upon the occurrence of certain
Events of Default, and upon the conditions stated in the Agreement, such
acceleration shall be automatic), without notice (except as otherwise required
by the Agreement), demand, or
<PAGE>
 
presentment, all of which are hereby waived, and the holder hereof shall have
the right to offset against this Note any sum or sums owed by the holder hereof
to Maker.  All past-due principal of and, to the extent permitted by law,
accrued interest on this Note shall, at the option of the holder hereof, bear
interest at the lesser of (a) the Maximum Lawful Rate or (b) the Adjusted Base
Rate plus 2% until paid.

     Notwithstanding the foregoing, if at any time, any rate of interest
calculated under Section 2.5 of the Agreement (the "Contract Rate") exceeds the
                 -----------                        -------------              
Maximum Lawful Rate, the rate of interest hereunder shall be limited to the
Maximum Lawful Rate, but any subsequent reductions in the Contract Rate shall
not reduce the rate of interest on this Note below the Maximum Lawful Rate until
the total amount of interest accrued equals the amount of interest which would
have accrued (including the amount of interest which would have accrued prior to
the payment or prepayment of any portion of this Note) if the Contract Rate had
at all times been in effect.  In the event that at maturity (stated or by
acceleration), or at final payment of this Note, the total amount of interest
paid or accrued on this Note is less than the amount of interest which would
have accrued if the Contract Rate had at all times been in effect with respect
thereto, then at such time the Maker shall pay to the holder of this Note an
amount equal to the difference between (a) the lesser of the amount of interest
which would have accrued if the Contract Rate had at all times been in effect
and the amount of interest which would have accrued if the Maximum Lawful Rate
had at all times been in effect, and (b) the amount of interest actually paid or
accrued on this Note.



                              PATINA OIL & GAS CORPORATION,
                              a Delaware corporation



                              By:   /s/ David J. Kornder
                                    --------------------------------
                                    David J. Kornder,
                              Its:  Vice President

                                       2
<PAGE>
 
                            LOANS, MATURITIES, AND
                      PAYMENTS OF PRINCIPAL AND INTEREST

<TABLE>
<CAPTION>
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                Payee's                                                                        
               Commitment        Expiration of      Rate of Interest                                      Unpaid      
 Borrowing     Percentage of        Interest          Applicable to       Amount of        Amount of     Principal    Notation Made
    Date        Borrowing           Period              Tranche         Principal Paid   Interest Paid    Balance          By
====================================================================================================================================

 <S>           <C>               <C>                <C>                 <C>              <C>             <C>          <C>
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</TABLE>

                                       3
<PAGE>
 
                                   EXHIBIT B
                                   ---------

                               PLEDGE AGREEMENT

     THIS PLEDGE AGREEMENT (this "Pledge Agreement") is dated as of the 1st day
of April, 1997, by and between PATINA OIL & GAS CORPORATION, a Delaware
corporation ("Pledgor"), and TEXAS COMMERCE BANK NATIONAL ASSOCIATION, a
              -------
national banking association, as Administrative Agent for the Banks (as defined
herein) (Texas Commerce Bank National Association in its capacity as
Administrative Agent for the Banks is hereinafter referred to as "Pledgee").
                                                                  -------   

                             W I T N E S S E T H:
                             - - - - - - - - - - 


     WHEREAS, Pledgor, Pledgee, NationsBank of Texas, N.A., as Documentary
Agent, Wells Fargo Bank, N.A., CIBC, Inc., and Credit Lyonnais, as Co-Agents,
Texas Commerce Bank National Association, individually, NationsBank of Texas,
N.A., individually, Wells Fargo Bank, N.A., individually, CIBC, Inc.,
individually, Credit Lyonnais New York Branch, individually, and Bank One,
Texas, N.A., individually (Texas Commerce Bank National Association,
individually, NationsBank of Texas, N.A., individually, Wells Fargo Bank, N.A.,
individually, CIBC, Inc., individually, Credit Lyonnais New York Branch,
individually, and Bank One, Texas, N.A., individually are herein collectively
referred to as "Banks") are parties to that certain Amended and Restated Credit
                -----
Agreement (the "Credit Agreement") dated effective as of April 1, 1997, pursuant
                ----------------
to which Banks have agreed to (i) make a revolving credit loan to Pledgor, and
(ii) issue and participate in Letters of Credit for the account of Pledgor and
its Restricted Subsidiaries (unless otherwise defined herein, all terms used
herein with their initial letter capitalized shall have the meaning given such
terms in the Credit Agreement); and

     WHEREAS, it is a condition to the agreement of Banks to make the Loan and
issue and participate in Letters of Credit and Letter of Credit Exposure under
the Credit Agreement that Pledgor execute and deliver this Pledge Agreement in
favor of Pledgee.
 
     NOW, THEREFORE, for valuable consideration, receipt of which is hereby
acknowledged and confessed, Pledgor agrees with Pledgee as follows:

     1.   Pledge.  Upon the terms hereof, Pledgor hereby grants to Pledgee, for
          ------
the ratable benefit of each Bank and any holder from time to time of the Notes,
a security interest in and to the rights, titles and interests of Pledgor in and
to all of the following rights, interests and property: (a) all of the issued
and outstanding shares of capital stock and other investment property issued by
SOCO Wattenberg Corporation, a Delaware corporation, and any other Restricted
Subsidiary of Pledgor, now owned or hereafter acquired, (collectively, the
"Restricted Subsidiaries" and individually, a "Restricted Subsidiary"),
 -----------------------                       ---------------------    
including, without limitation, the shares of the Restricted
<PAGE>
 
Subsidiaries owned by Pledgor on the date hereof (the "Pledged Shares"); and (b)
                                                       --------------           
any and all proceeds or other sums arising from or by virtue of, and all
dividends and distributions (cash or otherwise) payable and/or distributable
with respect to, all or any of the Pledged Shares described in clause (a)
preceding (the rights, interests and property described in clauses (a) and (b)
preceding are collectively referred to herein as the "Collateral").
                                                      ----------   

     2.   Secured Obligation.  The security interest herein granted (the
          ------------------  
"Security Interest") shall secure payment and performance of the Obligations.
 -----------------

     3.   Representations and Warranties; Related Covenants.  Pledgor
          -------------------------------------------------
represents, warrants, covenants and agrees to and with Administrative Agent, for
the benefit of each Bank, that: (a) Pledgor is the legal and beneficial owner of
the Pledged Shares issued by the Restricted Subsidiaries; (b) the Pledged Shares
are duly authorized and issued, fully paid and non-assessable, and all
documentary, stamp or other taxes or fees owing in connection with the issuance,
transfer and/or pledge thereof hereunder have been paid; (c) no dispute, right
of setoff, counterclaim or defense exists with respect to all or any part of the
Collateral; (d) the Collateral is free and clear of all Liens, options,
warrants, puts, calls or other rights of third persons, and restrictions, other
than (i) those Liens arising under this Pledge Agreement or any other of the
Loan Papers and Liens for Taxes not yet due and payable, and (ii) restrictions
on transferability imposed by applicable state and federal securities laws; (e)
Pledgor has full right and authority to pledge the Pledged Shares and other
Collateral for the purposes and upon the terms set out herein; (f) certificates
representing the Pledged Shares have been delivered to Pledgee, together with a
duly executed blank stock power with signatures guaranteed, for each
certificate; (g) the Pledged Shares constitute all of the issued and outstanding
capital stock of the Restricted Subsidiaries of every class; and (h) the
Restricted Subsidiaries have not issued, and there are not outstanding, any
options, warrants or other rights to acquire capital stock of the Restricted
Subsidiaries.

     4.   Covenants.  (a) Pledgor covenants and agrees to, from time to time,
          ---------
promptly execute and deliver to Pledgee all such other assignments,
certificates, supplemental writings and financing statements as Pledgee
reasonably requests in order to perfect or evidence the Security Interest.
Pledgor further agrees that if Pledgor shall at any time acquire any additional
shares of the capital stock or other investment property issued by any
Restricted Subsidiary, and whether such acquisition shall be by purchase,
exchange, reclassification, dividend, or otherwise, Pledgor shall forthwith (and
without the necessity for any request or demand by Pledgee) deliver the
certificates representing such capital stock or investment property to Pledgee,
in the same manner and with the same effect as described in paragraphs 1 and 3
hereof.  Such capital stock or investment property shall constitute "Pledged
                                                                     -------
Shares" and "Collateral" and shall be subject to the Liens herein created, for
------       ----------                                                       
the purposes and upon the terms and conditions set forth in this Pledge
Agreement and the other Loan Papers. Pledgor further covenants and agrees that,
without the prior written consent of all Banks, Pledgor shall not (i) transfer
any of Pledgor's rights, titles or interests in and to the Collateral or any
part thereof; or (ii) create any other Lien or otherwise encumber any of the
Collateral, or permit any of the Collateral to ever be or become subject to any
Lien, attachment, execution, sequestration, other legal or equitable process or
any Lien or encumbrance of any kind, except the Security Interest.
<PAGE>
 
     (b)  Pledgor will promptly execute and deliver, or cause the execution and
delivery of, all applications, certificates, instruments, registration
statements, and all other documents and papers Pledgee may reasonably request in
connection with the obtaining of any consent, approval, registration,
qualification, or authorization of any other Person necessary or appropriate for
the effective exercise of any rights under this Pledge Agreement. Without
limiting the generality of the foregoing, Pledgor agrees that in the event
Pledgee shall exercise any rights to sell, transfer, or otherwise dispose of, or
vote, consent, or take any other action in connection with any of the Collateral
pursuant to this Pledge Agreement, Pledgor shall execute and deliver all
applications, certificates, and other documents as Pledgee may reasonably
request and shall otherwise promptly, fully and diligently cooperate with
Pledgee and any other necessary Persons, in making any application for the prior
consent or approval of any other Person to the exercise by Pledgee of any rights
relating to all or any of the Collateral. Furthermore, because Pledgor agrees
that Pledgee's remedies at law for failure of Pledgor to comply with the
provisions of this paragraph 4(b) would be inadequate and that such failure
would not be adequately compensable in damages, Pledgor agrees that the
covenants of this paragraph 4(b) may be specifically enforced.

     (c)  Pledgor will preserve, warrant, and defend the Liens created hereby in
the Collateral against the claims of all Persons whomsoever; will maintain and
preserve such Liens at all times as contemplated by the Loan Papers; will not at
any time assign, transfer, or otherwise dispose of its right, title and interest
in and to any of the Collateral; will not at any time directly or indirectly
create, assume, or suffer to exist any Lien, warrant, put, option, or other
rights of third Persons and restrictions, other than the Liens created by this
Pledge Agreement in and to the Collateral or any part thereof; and will not do
or suffer any matter or thing whereby the Liens created by this Pledge Agreement
in and to the Collateral might or could be impaired.

     5.   Conversions; Etc.  Should the Collateral, or any part thereof, ever be
          ----------------
in any manner converted by any Restricted Subsidiary into another property of
the same or another type or any money or other proceeds ever be paid or
delivered to Pledgor as a result of Pledgor's rights in the Collateral, then, in
any such event (except as otherwise provided herein), all such property, money
and other proceeds shall be and/or become part of the Collateral, and Pledgor
covenants forthwith to pay or deliver to Pledgee (as pledgeholder for the pro
rata benefit of each Bank as provided above) all of the same which is
susceptible of delivery; and at the same time, if any Bank deems it necessary
and so requests, Pledgor will properly endorse or assign the same to Pledgee (as
pledgeholder for the pro rata benefit of each Bank as provided above). Without
limiting the generality of the foregoing, Pledgor hereby agrees that the shares
of capital stock or other investment property of the surviving corporation in
any merger or consolidation involving any Restricted Subsidiary shall be deemed
to constitute the same property as the Collateral. With respect to any such
property of a kind requiring an additional security agreement, financing
statement or other writing to perfect a security interest therein in favor of
Pledgee (as pledgeholder for the pro rata benefit of each Bank as provided
above), Pledgor will forthwith execute and deliver to Pledgee whatever any Bank
shall deem necessary or proper for such purpose.

                                       3
<PAGE>
 
     6.   No Duty to Fix or Preserve Rights.  Neither Pledgee nor any Bank shall
          ---------------------------------                                     
have any duty to fix or preserve rights against prior parties to the Collateral
or shall ever be liable for failure to use diligence to collect any amount
payable with respect to the Pledged Shares, or any part thereof, but shall be
liable only to account to Pledgor for what such Bank may actually collect or
receive thereon.

     7.   Rights of Parties Before and After the Occurrence of a Default.
          -------------------------------------------------------------- 

     (a)  Exercising Shareholder Rights Prior to a Default.  Unless and until a
          ------------------------------------------------
Default shall occur,

          (i)  Pledgor shall be entitled to receive all cash dividends paid out
               of net income on a current basis to Pledgor in respect of or
               attributable to the Pledged Shares or other Collateral.
               Notwithstanding the foregoing, Pledgee shall be entitled to
               receive, whether or not a Default has occurred, (A) any and all
               other Distributions, including, but not limited to, stock
               dividends, liquidating Distributions or other Distributions in
               property made on or with respect to the Pledged Shares or any
               other Collateral and any proceeds of Collateral, whether
               resulting from subdivision, combination, or reclassification of
               the outstanding capital stock or other investment property issued
               by any Restricted Subsidiary or as a result of any merger,
               consolidation, acquisition, or other exchange of assets (whether
               or not permitted by any Loan Paper), or to which any Restricted
               Subsidiary is a party, and (B) all sums paid on any Collateral
               upon liquidation or dissolution or reduction of capital,
               repurchase, retirement, or redemption. All such sums, dividends,
               distributions, proceeds, or other property described in clauses
               (A) and (B) preceding shall, if received by any Person other than
               Pledgee, be held in trust for the benefit of Pledgee and shall
               forthwith be delivered to Pledgee (accompanied by proper
               instruments of assignment and/or stock and/or bond powers
               executed by Pledgor in accordance with Pledgee's instructions) to
               be held subject to the terms of this Pledge Agreement. Any cash
               proceeds of the Collateral, other than cash dividends which
               Pledgor is then permitted to receive and retain under the Loan
               Papers, which come into the possession of Pledgee may, at
               Pledgee's option, be applied in whole or in part to the
               Obligations (to the extent then due), be released in whole or in
               part to or on the written instructions of Pledgor for any general
               or specific purpose otherwise permitted by the Loan Papers, or be
               retained in whole or in part by Pledgee as additional security
               for the payment and performance of the Obligations. All interest
               and other amounts earned from any investment of such proceeds may
               be dealt with by Pledgee in the same manner as other cash
               proceeds; and

          (ii) Pledgor shall have the right to vote and give consents with
               respect to all of the Collateral and to consent to, ratify, or
               waive notice of any and all meetings; provided that such right
                                                     -------- ----
               shall in no case be exercised for any

                                       4
<PAGE>
 
               purpose contrary to, or in violation of, any of the terms or the
               provisions of this Pledge Agreement, the Credit Agreement, or any
               other Loan Paper.

     (b)  Exercising Shareholder Rights After the Occurrence of a Default.  Upon
          ---------------------------------------------------------------       
the occurrence of a Default, Pledgee, without the consent of Pledgor, may:

          (i)  At any time vote or consent in respect of any of the Pledged
               Shares and authorize any Collateral to be voted and such consents
               to be given, ratify and waive notice of any and all meetings, and
               take such other action as shall seem desirable to Pledgee, in its
               discretion, to protect or further the interests of Banks and
               Pledgee in respect of any of the Pledged Shares as though it were
               the outright owner thereof, and Pledgor hereby irrevocably
               constitutes and appoints Pledgee its sole proxy and attorney-in-
               fact, with full power of substitution to vote and act with
               respect to any and all Pledged Shares standing in the name of
               Pledgor or with respect to which Pledgor is entitled to vote and
               act. The proxy and power of attorney herein granted are coupled
               with interests, are irrevocable, and shall continue throughout
               the term of this Pledge Agreement;

          (ii) In respect of any Pledged Shares, join in and become a party to
               any plan of recapitalization, reorganization, or readjustment
               (whether voluntary or involuntary) as shall seem desirable to
               Pledgee in respect of any such Pledged Shares, and deposit any
               such Pledged Shares under any such plan; make any exchange,
               substitution, cancellation, or surrender of such Pledged Shares
               required by any such plan and take such action with respect to
               any such Pledged Shares as may be required by any such plan or
               for the accomplishment thereof; and no such disposition,
               exchange, substitution, cancellation, or surrender shall be
               deemed to constitute a release of Pledged Shares from the Lien of
               this Pledge Agreement;

          (iii)Receive all payments of whatever kind made upon or with respect
               to any Collateral; and

          (vi) Transfer into its name, or into the name or names of its nominee
               or nominees, all or any of the Collateral.

     (c)  Right of Sale After the Occurrence of a Default.  Upon the occurrence
          -----------------------------------------------                      
of a Default, Pledgee may sell, without recourse to judicial proceedings, with
the right (except at private sale) to bid for and buy, free from any right of
redemption, the Pledged Shares or any part thereof, upon five (5) days' notice
(which notice is agreed to be reasonable notice for the purposes hereof) to
Pledgor of the time and place of sale, for cash, upon credit or for future
delivery, at Pledgee's option and in Pledgee's complete discretion:

                                       5
<PAGE>
 
          (i)  At public sale, including a sale at any broker's board or
               exchange;

          (ii) At private sale in any manner which will not require the Pledged
               Shares, or any part thereof, to be registered in accordance with
               The Securities Act of 1933 (as amended, the "Act") or the rules
                                                            ---
               and regulations promulgated thereunder, or any other law or
               regulation, at the best price reasonably obtainable by Pledgee at
               any such private sale or other disposition in the manner
               mentioned above. Pledgee is also hereby authorized, but not
               obligated, to take such actions, give such notices, obtain such
               consents, and do such other things as Pledgee may deem required
               or appropriate in the event of sale or disposition of any of the
               Pledged Shares. Pledgor understands that Pledgee may in its
               discretion approach a restricted number of potential purchasers
               and that a sale under such circumstances may yield a lower price
               for the Pledged Shares, or any portion thereof, than would
               otherwise be obtainable if the same were registered and sold in
               the open market. Pledgor agrees (a) that in the event Pledgee
               shall so sell the Pledged Shares, or any portion thereof, at such
               private sale or sales, Pledgee shall have the right to rely upon
               the advice and opinion of any member firm of a national
               securities exchange as to the best price reasonably obtainable
               upon such a private sale thereof (any expense borne by Pledgee in
               obtaining such advice to be paid by Pledgor as an expense related
               to the exercise by Pledgee of its rights hereunder), and (B) that
               such reliance shall be conclusive evidence that Pledgee handled
               such matter in a commercially reasonable manner.

     In case of any sale by the Pledgee of the Pledged Shares on credit or for
future delivery, the Pledged Shares sold may be retained by Pledgee until the
selling price is paid by the purchaser, but Pledgee shall incur no liability in
case of failure of the purchaser to take up and pay for the Pledged Shares so
sold.  In case of any such failure, such Pledged Shares so sold may be again
similarly sold.

     In connection with the sale of the Pledged Shares, Pledgee is authorized,
but not obligated, to limit prospective purchasers to the extent deemed
necessary or desirable by Pledgee to render such sale exempt from the
registration requirements of the Act, and any applicable state securities laws,
and no sale so made in good faith by Pledgee shall be deemed not to be
"commercially reasonable" because so made.  If Pledgee determines to exercise
its right to sell all or any of the Pledged Shares, and if in the opinion of
Gardere & Wynne, L.L.P. or such other reputable law firm selected by Pledgee
("Law Firm"), it is necessary or advisable to have such securities registered
  --------                                                                   
under the provisions of such Act, or any similar law relating to the
registration of securities, Pledgor agrees, at its own expense, to (i) execute
and deliver all such instruments and documents, and to do or cause to be done
other such acts and things as may be necessary or, in the opinion of Law Firm,
advisable to register such securities under the provisions of such Act or any
applicable similar law relating to the registration of securities, and Pledgor
will use its best efforts to cause the registration statement relating thereto
to become effective and to remain effective for such period as Pledgee shall

                                       6
<PAGE>
 
reasonably request, and to make all amendments thereof and/or to the related
prospectus which, in the opinion of Law Firm, are necessary or desirable, all in
conformity with the requirements of such Act and the rules and regulations of
the Securities and Exchange Commission applicable thereto; (ii) use its best
efforts to qualify such securities under state "blue sky" or securities laws and
to obtain the necessary approval of any Tribunal (as hereinafter defined) to the
sale of such securities, all as reasonably requested by Pledgee; and (iii) at
the request of Pledgee, indemnify and hold harmless, and to cause the Restricted
Subsidiaries to agree to indemnify and hold harmless, Pledgee, each Bank, any
underwriters (and any Person controlling any of the foregoing), and their
respective employees, officers, agents, attorneys, and accountants
(collectively, the "Indemnified Parties") from and against any loss, liability,
                    -------------------                                        
claim, damage and expense (including without limitation, reasonable fees of
counsel incurred in connection therewith) under such Act or otherwise, insofar
as such loss, liability, claim, damage or expense arises out of or is based upon
any untrue statement or alleged untrue statement of any material fact contained
in any registration statement under which such securities were registered under
such Act or other securities laws, any preliminary prospectus or final
prospectus contained therein, or any amendment or supplement thereto, or arise
out of or are based upon any omission or any alleged omission to state therein a
material fact required to be stated or necessary to make the statements therein
not misleading, such indemnification to remain operative regardless of any
investigation made by or on behalf of any Indemnified Party; provided that
Pledgor shall not be liable in any case to the extent that any such loss,
liability, claim, damage, or expense arises out of or is based upon any untrue
statement or alleged untrue statement or an omission or an alleged omission made
in reliance upon and in conformity with written information furnished to Pledgor
and/or the Restricted Subsidiaries by an Indemnified Party.  As used in this
Paragraph 9(c) and in Paragraph 15(a), the term "Tribunal" means any court or
                                                 --------                    
governmental department, commission, board, bureau, agency or instrumentality of
the United State or of a state, commonwealth, nation, territory, possession,
county, parish, or municipality, whether now or hereinafter constituted or
existing.

     (d)  Other Rights After a Default.  Upon the occurrence of a Default,
          ----------------------------                                    
Pledgee, at its election (but subject to the terms and conditions of the Credit
Agreement) may exercise any and all rights available to a secured party under
the Uniform Commercial Code as enacted in the State of Texas or other applicable
jurisdiction, as amended, in addition to any and all other rights afforded by
the Loan Papers, at law, in equity, or otherwise.

     (e)  Application of Proceeds.  Pledgee shall apply the proceeds of any sale
          -----------------------                                               
or other disposition of the Pledged Shares in the manner provided in the Credit
Agreement.

     8.   Notices.  Whenever this Pledge Agreement requires or permits any
          -------                                                         
consent, approval, notice, request, or demand from one party to another, the
consent, approval, notice, request, or demand must be given in the manner
provided in Section 14.1 of the Credit Agreement.

     9.   Right to File as Financing Statement.  Pledgee or any Bank shall have
          ------------------------------------                                 
the right at any time to execute and file this Pledge Agreement as a financing
statement, but the failure of Pledgee or any Bank to do so shall not impair the
validity or enforceability of this Pledge Agreement.

                                       7
<PAGE>
 
     10.  Waiver of Certain Rights.  (a) To the full extent that it may lawfully
          ------------------------                                              
so agree, Pledgor agrees that it will not at any time plead, claim or take the
benefit of any appraisement, valuation, stay, extension, moratorium or
redemption law now or hereafter in force in order to prevent or delay the
enforcement of this Pledge Agreement, or the absolute sale of all or any part of
the Pledges Shares or the possession thereof by any purchaser at any sale
hereunder, and Pledgor hereby waives the benefit of all such laws to the extent
it lawfully may.  Each right, power and remedy of Pledgee provided for in this
Pledge Agreement or now or hereafter existing at law or in equity or by statute
or otherwise shall be cumulative and concurrent and shall be in addition to
every other right, power or remedy provided for in this Pledge Agreement or now
or hereafter existing at law or in equity or by statute or otherwise, and the
exercise or beginning of the exercise by Pledgee of any one or more of such
rights, power or remedies shall not preclude the simultaneous or later exercise
by Pledgee of any or all such other rights, powers or remedies.  No failure or
delay on the part of Pledgee to exercise any such right, power or remedy and no
notice or demand which may be given to or made upon Pledgor by Pledgee with
respect to any such remedies shall operate as a waiver thereof, or limit or
impair Pledgee's right to take any action or to exercise any power or remedy
hereunder, without notice or demand, or prejudice its rights as against Pledgor
in any respect.

     (b)  Except to the extent required under the Credit Agreement or any other
Loan Paper, Pledgor hereby waives diligence, presentment, demand, protest and
notice of any kind whatsoever in respect of the Notes as well as any requirement
that the Pledgee or any holder of any of the Notes exhausts any right or remedy
or takes any action in connection with the Notes or the Loan Papers before
exercising any right or remedy under this Pledge Agreement.  The obligations of
Pledgor hereunder shall not be affected or impaired by reason of the happening
from time to time of any of the following, although without notice to or the
consent of Pledgor:

     (i)  the waiver by Pledgee or any of the holders of the Notes of the
          performance or observance by Pledgor or any other Borrower of any of
          its agreements, covenants, terms or conditions contained in the Loan
          Papers or in any Note;

    (ii)  the voluntary or involuntary liquidation, dissolution, sale of all or
          substantially all of the assets, marshaling of assets and liabilities,
          receivership, conservatorship, insolvency, bankruptcy, assignment for
          the benefit of creditors, reorganization, arrangement, winding up, or
          other similar proceedings affecting Pledgor, the Restricted
          Subsidiaries or any Borrower;

   (iii)  the release by operation of law of Pledgor or any other Borrower from
          the performance or observance of any of the agreements, covenants,
          terms or conditions contained in any of the Loan Papers; or

    (iv)  the release of any security for the Notes, whether under this Pledge
          Agreement or any of the Loan Papers.

                                       8
<PAGE>
 
     11.  Amendments.  This Pledge Agreement may be amended only by an
          ----------                                                  
instrument in writing executed jointly by Pledgor and Pledgee (subject to the
approval of the requisite Banks as provided in the Credit Agreement) and
supplemented only by documents delivered or to be delivered in accordance with
the express terms hereof.

     12.  Multiple Counterparts.  This Pledge Agreement may be executed in a
          ---------------------                                             
number of identical counterparts, each of which shall be deemed an original for
all purposes and all of which shall constitute, collectively, one agreement;
but, in making proof of this Pledge Agreement, it shall not be necessary to
produce or account for more than one such counterpart.

     13.  Parties Bound; Assignment.  This Pledge Agreement shall be binding on
          -------------------------                                            
Pledgor and Pledgor's successors and assigns and shall inure to the benefit of
Pledgee and Pledgee's successor and assigns.

     14.  Invalid Provisions.  If any provision of this Pledge Agreement is held
          ------------------                                                    
to be illegal, invalid, or unenforceable under present or future laws effective
during the term hereof, such provision shall be fully severable, this Pledge
Agreement shall be construed and enforced as if such illegal, invalid, or
unenforceable provision had never comprised a part hereof, and the remaining
provisions hereof shall remain in full force and effect and shall not be
affected by the illegal, invalid, or unenforceable provision or by its severance
herefrom.  Furthermore, in lieu of such illegal, invalid, or unenforceable
provision there shall be added automatically as a part of this Pledge Agreement
a provision as similar in terms to such illegal, invalid, or unenforceable
provision as may be possible and be legal, valid and enforceable.

     15.  COMPLETE AGREEMENT.  THIS PLEDGE AGREEMENT AND THE OTHER LOAN PAPERS
          ------------------                                                  
COLLECTIVELY REPRESENT THE FINAL AGREEMENT BY AND AMONG PLEDGEE AND PLEDGOR AND
MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR SUBSEQUENT
ORAL AGREEMENTS OF PLEDGOR AND PLEDGEE.  THERE ARE NO UNWRITTEN ORAL AGREEMENTS
BETWEEN PLEDGOR AND PLEDGEE.

     16.  WAIVER OF JURY TRIAL.  PLEDGOR, FOR ITSELF, ITS SUCCESSORS AND
          --------------------                                          
ASSIGNS,  AND THE PLEDGEE HEREBY IRREVOCABLY WAIVE, TO THE FULLEST EXTENT
PERMITTED BY LAW, THEIR RIGHT TO A JURY TRIAL IN ANY LITIGATION ARISING OUT OF
OR IN CONNECTION WITH THIS PLEDGE AGREEMENT OR ANY OF THE OTHER LOAN PAPERS AND
FOR ANY COUNTERCLAIM THEREIN.

     17.  TEXAS LAW.  THIS PLEDGE AGREEMENT AND THE OTHER LOAN PAPERS HAVE BEEN
          ---------                                                            
EXECUTED AND DELIVERED IN THE STATE OF TEXAS AND SHALL BE CONSTRUED IN
ACCORDANCE WITH AND GOVERNED BY THE LAWS OF THE STATE OF TEXAS AND THE LAWS OF
THE UNITED STATES OF AMERICA, EXCEPT TO THE EXTENT THAT THE LAWS OF ANY STATE IN
WHICH ANY PROPERTY INTENDED AS SECURITY FOR THE OBLIGATIONS IS LOCATED
NECESSARILY GOVERN (A) THE

                                       9
<PAGE>
 
PERFECTION AND PRIORITY OF THE LIENS IN FAVOR OF PLEDGEE WITH RESPECT TO SUCH
PROPERTY, AND (B) THE EXERCISE OF ANY REMEDIES (INCLUDING FORECLOSURE) WITH
RESPECT TO SUCH PROPERTY.

     EXECUTED as of April 1, 1997.

                                PLEDGOR:

                                PATINA OIL & GAS CORPORATION,
                                a Delaware corporation


                                By:  /s/ David J. Kornder
                                     --------------------------
                                     David J. Kornder,
                                     Vice President



ACCEPTED AND AGREED as of the
1st day of April, 1997,

TEXAS COMMERCE BANK NATIONAL ASSOCIATION,
as Administrative Agent for the Banks


By:  /s/ Dale S. Hurd
     ----------------------------
     Dale S. Hurd,
     Senior Vice President

                                      10
<PAGE>
 
                                   EXHIBIT C
                                   ---------

                                   GUARANTY


     THIS GUARANTY (this "Guaranty") is dated as of the 1st day of April, 1997,
                          --------                                             
by SOCO Wattenberg Corporation, a Delaware corporation ("Guarantor"), in favor
                                                         ---------            
of TEXAS COMMERCE BANK NATIONAL ASSOCIATION, NATIONSBANK OF TEXAS, N.A., CIBC,
INC., CREDIT LYONNAIS NEW YORK BRANCH, WELLS FARGO BANK, N.A., and BANK ONE,
TEXAS, N.A. and each of their successors and assigns as permitted pursuant to
Section 14.10 of the Credit Agreement (Texas Commerce Bank National Association
[acting as Bank but not as Administrative Agent], NationsBank of Texas, N.A.
[acting as a Bank but not as Documentary Agent], CIBC, Inc., Credit Lyonnais New
York Branch and Wells Fargo Bank, N.A. [each acting as a Bank but not as Co-
Agents] and Bank One, Texas, N.A. acting as a Bank, and each of their successors
and assigns are collectively referred to herein as "Noteholders").

                             W I T N E S S E T H:
                             - - - - - - - - - - 

     WHEREAS, Patina Oil & Gas Corporation, a Delaware corporation ("Borrower"),
                                                                     --------   
Noteholders, Texas Commerce Bank National Association, as Administrative Agent
("Administrative Agent"), NationsBank of Texas, N.A., as Documentary Agent and
  --------------------                                                        
CIBC, Inc., Credit Lyonnais and Wells Fargo Bank, N.A., as Co-Agents are parties
to that certain Amended and Restated Credit Agreement (the "Credit Agreement")
                                                            ----------------  
dated effective as of April 1, 1997, pursuant to which Noteholders have agreed
to (i) make a revolving credit loan to Patina, and (ii) issue and participate in
Letters of Credit issued on behalf of Borrower and certain of its Restricted
Subsidiaries (unless otherwise defined herein, all terms used herein with their
initial letter capitalized shall have the meaning given such terms in the Credit
Agreement); and

     WHEREAS, Noteholders have required, as a condition to making the Loan under
the Credit Agreement, that Guarantor execute and deliver this Guaranty; and

     WHEREAS, Guarantor has determined that valuable benefits will be derived by
it as a result of the Credit Agreement and the Loan to be made by Banks
thereunder; and

     WHEREAS, Guarantor has further determined that the benefits accruing to it
from the Credit Agreement exceed Guarantor's anticipated liability under this
Guaranty.

     NOW, THEREFORE, for valuable consideration, the receipt and sufficiency of
which are hereby acknowledged and confessed, Guarantor hereby covenants and
agrees as follows:

     1.  Guarantor hereby absolutely and unconditionally guarantees the prompt,
complete and full payment when due, no matter how such shall become due, of the
Obligations, and further guarantees that Borrower will properly and timely
perform the Obligations.  Notwithstanding any contrary provision in this
Guaranty, however, Guarantor's maximum liability under this Guaranty
<PAGE>
 
is limited, to the extent, if any, required so that its liability is not subject
to avoidance under applicable Debtor Relief Laws (as such term is defined in
Paragraph 8 hereof).

     2.  If Guarantor is or becomes liable for any indebtedness owing by
Borrower to Noteholders by endorsement or otherwise than under this Guaranty,
such liability shall not be in any manner impaired or affected hereby, and the
rights of Noteholders hereunder shall be cumulative of any and all other rights
that Noteholders may ever have against Guarantor.  The exercise by Noteholders
of any right or remedy hereunder or under any other instrument, at law or in
equity, shall not preclude the concurrent or subsequent exercise of any other
right or remedy.

     3.  In the event of default by Borrower in payment of the Obligations, or
any part thereof, when such Obligations become due, either by their terms or as
the result of the exercise of any power to accelerate, Guarantor shall, on
demand, and without further notice of dishonor and without any notice having
been given to Guarantor previous to such demand of the acceptance by Noteholders
of this Guaranty, and without any notice having been given to such Guarantor
previous to such demand of the creating or incurring of such Obligations, pay
the amount due thereon to Noteholders at the Administrative Agent's office as
set forth in the Credit Agreement, and it shall not be necessary for any
Noteholder, in order to enforce such payment by Guarantor, first, to institute
suit or exhaust its remedies against Borrower or others liable on such
Obligations, to have Borrower joined with Guarantor in any suit brought under
this Guaranty or to enforce their rights against any security which shall ever
have been given to secure such indebtedness; provided, however, that in the
event Noteholders elect to enforce and/or exercise any remedies they may possess
with respect to any security for the Obligations prior to demanding payment from
Guarantor, Guarantor shall nevertheless be obligated hereunder for any and all
sums still owing to Noteholders on the Obligations and not repaid or recovered
incident to the exercise of such remedies.

     4.  Notice to Guarantor of the acceptance of this Guaranty and of the
making, renewing or assignment of the Obligations and each item thereof, are
hereby expressly waived by Guarantor.

     5.  Each payment on the Obligations shall be deemed to have been made by
Borrower unless express written notice is given to Administrative Agent at the
time of such payment that such payment is made by  Guarantor as specified in
such notice.

     6.  If all or any part of the Obligations at any time are secured,
Guarantor agrees that Noteholders may at any time and from time to time, at
their discretion and with or without valuable consideration, allow substitution
or withdrawal of collateral or other security and release collateral or other
security or compromise or settle any amount due or owing under the Credit
Agreement or amend or modify in whole or in part the Credit Agreement or any
Loan Papers executed in connection with same without impairing or diminishing
the obligations of Guarantor hereunder. Guarantor further agrees that if
Borrower executes in favor of Noteholders any collateral agreement, mortgage or
other security instrument, the exercise by Noteholders of any right or remedy
thereby conferred on Noteholders shall be wholly discretionary with Noteholders,
and that the exercise or failure to exercise any such right or remedy shall in
no way impair or diminish the obligation of Guarantor hereunder.  Guarantor
further agrees that Noteholders and Administrative Agent shall not be liable for
their failure to use diligence in the collection of the Obligations or in
preserving the

                                       2
<PAGE>
 
liability of any person liable for the Obligations, and Guarantor hereby waives
presentment for payment, notice of nonpayment, protest and notice thereof
(including, notice of acceleration), and diligence in bringing suits against any
Person liable on the Obligations, or any part thereof.

     7.   Guarantor agrees that Noteholders, in their discretion, may (i) bring
suit against all guarantors (including, without limitation, Guarantor hereunder)
of the Obligations jointly and severally or against any one or more of them,
(ii) compound or settle with any one or more of such guarantors for such
consideration as the Noteholders may deem proper, and (iii) release one or more
of such guarantors from liability hereunder, and that no such action shall
impair the rights of Noteholders to collect the Obligations (or the unpaid
balance thereof) from other such guarantors of the Obligations, or any of them,
not so sued, settled with or released. Guarantor agrees, however, that nothing
contained in this paragraph, and no action by Noteholders permitted under this
paragraph, shall in any way affect or impair the rights or obligations of such
guarantors among themselves.

     8.   Guarantor represents and warrants to Noteholders that (i) Guarantor is
a corporation duly organized and validly existing under the laws of the State of
Delaware; and (ii) Guarantor possesses all requisite authority and power to
authorize, execute, deliver and comply with the terms of this Guaranty; this
Guaranty has been duly authorized and approved by all necessary action on the
part of Guarantor and constitutes a valid and binding obligation of Guarantor
enforceable in accordance with its terms, except as the enforcement thereof may
be limited by applicable Debtor Relief Laws; and no approval or consent of any
court or governmental entity is required for the authorization, execution,
delivery or compliance with this Guaranty which has not been obtained (and
copies thereof delivered to Noteholders).  As used in this Paragraph 8, "Debtor
                                                                         ------
Relief Laws" means the Bankruptcy Code of the United States of America and all
-----------                                                                   
other applicable liquidation, conservatorship, bankruptcy, moratorium,
rearrangement, receivership, insolvency, reorganization, suspension of payments
or similar debtor relief laws from time to time in effect affecting the rights
of creditors generally.

     9.   Guarantor covenants and agrees that until the Obligations are paid and
performed in full, except as otherwise provided in the Credit Agreement or
unless Noteholders give their prior written consent to any deviation therefrom,
it will (i) at all times maintain its existence and authority to transact
business in any State where Guarantor has assets and operations; and (ii)
promptly deliver to Noteholders and to Administrative Agent such information
respecting its business affairs, assets and liabilities as Noteholders may
reasonably request.  The failure of Guarantor to comply with the terms of this
paragraph shall be a Default under the Credit Agreement.

     10.  This Guaranty is for the benefit of the Noteholders, their successors
and assigns, and in the event of an assignment by Noteholders (or their
successors or assigns) of the Obligations, or any part thereof, the rights and
benefits hereunder, to the extent applicable to the Obligations so assigned, may
be transferred with such Obligations.  Subject to the preceding paragraph
hereof, this Guaranty is binding, not only on Guarantor, but on the legal
representatives, successors and assigns of Guarantor.

                                       3
<PAGE>
 
     11.  No modification, consent, amendment or waiver of any provision of this
Guaranty, nor consent to any departure by Guarantor therefrom, shall be
effective unless the same shall be in writing and signed by Required Banks, and
then shall be effective only in the specific instance and for the purpose for
which given.  No notice to or demand on Guarantor in any case shall, of itself,
entitle Guarantor to any other or further notice or demand in similar or other
circumstances.  No delay or omission by Noteholders in exercising any power or
right hereunder shall impair any such right or power or be construed as a waiver
thereof or any acquiescence therein, nor shall any single or partial exercise of
any such power preclude other or further exercise thereof, or the exercise of
any other right or power hereunder.  All rights and remedies of Noteholders
hereunder are cumulative of each other and of every other right or remedy which
Noteholders may otherwise have at law or in equity or under any other contract
or document, and the exercise of one or more rights or remedies shall not
prejudice or impair the concurrent or subsequent exercise of other rights or
remedies.

     12.  No provision herein or in any promissory note, instrument or any other
Loan Paper executed by Borrower or Guarantor evidencing the Obligations shall
require the payment or permit the collection of interest in excess of the
Maximum Lawful Rate.  If any excess of interest in such respect is provided for
herein or in any such promissory note, instrument, or any other Loan Paper, the
provisions of this paragraph shall govern, and neither Borrower nor Guarantor
shall be obligated to pay the amount of such interest to the extent that it is
in excess of the amount permitted by law. The intention of the parties being to
conform strictly to any applicable federal or state usury laws now in force, all
promissory notes, instruments and other Loan Papers executed by Borrower or
Guarantor evidencing the Obligations shall be held subject to reduction to the
amount allowed under said usury laws as now or hereafter construed by the courts
having jurisdiction.

     13.  If Guarantor should breach or fail to perform any provision of this
Guaranty, Guarantor agrees to pay Noteholders all costs and expenses (including
court costs and reasonable attorneys fees) incurred by Noteholders in the
enforcement hereof.

     14.  The liability of Guarantor under this Guaranty shall in no manner be
impaired, affected or released by the insolvency, bankruptcy, making of an
assignment for the benefit of creditors, arrangement, compensation, composition
or readjustment of Borrower, or any proceedings affecting the status, existence
or assets of Borrower or other similar proceedings instituted by or against
Borrower and affecting the assets of Borrower.

     15.  Guarantor understands and agrees that any amounts of Guarantor on
account with Noteholders may be offset to satisfy the obligations of Guarantor
hereunder.

     16.  Guarantor hereby subordinates and makes inferior any and all
indebtedness now or at any time hereafter owed by Borrower to Guarantor to the
Obligations evidenced by the Credit Agreement and agrees after the occurrence of
a Default under the Credit Agreement, or any event which with notice, lapse of
time, or both, would constitute a Default under the Credit Agreement, not to
permit Borrower to repay, or to accept payment from Borrower of, such
indebtedness or any part thereof without the prior written consent of
Noteholders.

                                       4
<PAGE>
 
     17.  Guarantor hereby waives any and all rights of subrogation to which
Guarantor may otherwise be entitled against Borrower, or any other guarantor of
the Obligations, as a result of any payment made by Guarantor pursuant to this
Guaranty.

     18.  As of the date hereof, the fair saleable value of the property of
Guarantor is greater than the total amount of liabilities (including contingent
and unliquidated liabilities) of Guarantor, and Guarantor is able to pay all of
its liabilities as such liabilities mature and Guarantor does not have
unreasonably small capital within the meaning of Section 548, Title 11, United
States Code, as amended.  In computing the amount of contingent or liquidated
liabilities, such liabilities have been computed at the amount which, in light
of all the facts and circumstances existing as of the date hereof, represents
the amount that can reasonably be expected to become an actual or matured
liability.

     19.  If any provision of this Guaranty is held to be illegal, invalid, or
unenforceable, such provision shall be fully severable; this Guaranty shall be
construed and enforced as if such illegal, invalid, or unenforceable provision
had never comprised a part hereof; and the remaining provisions hereof shall
remain in full force and effect and shall not be affected by the illegal,
invalid, or unenforceable provision or by its severance herefrom.  Furthermore,
in lieu of such illegal, invalid, or unenforceable provision there shall be
added automatically as a part of this Guaranty a provision as similar in terms
to such illegal, invalid, or unenforceable provision as may be possible and be
legal, valid and enforceable.

      20. (a)  Except to the extent required for the exercise of the remedies
provided in the other security instruments, Guarantor hereby irrevocably submits
to the nonexclusive jurisdiction of any Texas state or federal court over any
action or proceeding arising out of or relating to this Guaranty or any other
Loan Paper, and Guarantor hereby irrevocably agrees that all claims in respect
of such action or proceeding may be heard and determined in such Texas state or
federal court. Guarantor hereby irrevocably waives, to the fullest extent
permitted by Law, any objection which it may now or hereafter have to the laying
of venue of any Litigation arising out of or in connection with this Guaranty or
any of the Loan Papers brought in district courts of Dallas County, Texas, or in
the United States District Court for the Northern District of Texas, Dallas
Division.  Guarantor hereby irrevocably waives any claim that any Litigation
brought in any such court has been brought in an inconvenient forum.  Guarantor
hereby agrees to designate and maintain an agent for service of process in
Dallas, Texas in connection with any such Litigation and to deliver to
Noteholders evidence thereof.  Guarantor hereby irrevocably consents to the
service of process out of any of the aforementioned courts in any such
Litigation by the mailing of copies thereof by certified mail, return receipt
requested, postage prepaid, to Guarantor's office at 1625 Broadway Blvd., Suite
2200, Denver, Colorado  80202.  Guarantor irrevocably agrees that any legal
proceeding against Noteholders shall be brought in the district courts of Dallas
County, Texas, or in the United States District Court for the Northern District
of Texas, Dallas Division.  Nothing herein shall affect the right of Noteholders
to commence legal proceedings or otherwise proceed against Guarantor in any
jurisdiction or to serve process in any manner permitted by applicable law.  As
used herein, the term "Litigation" means any proceeding, claim, lawsuit or
                       ----------                                         
investigation (i) conducted or threatened by or before any court or governmental
department, commission, board, bureau, agency or instrumentality of the United
States or of any state, commonwealth, nation, territory, possession,

                                       5
<PAGE>
 
county, parish, or municipality, whether now or hereafter constituted or
existing, or (ii) pending before any public or private arbitration board or
panel.

     (b)  Nothing in this Paragraph 20 shall affect any right of the Noteholders
                          ------------                                          
to serve legal process in any other manner permitted by law or affect the right
of any Noteholder to bring any action or proceeding against Guarantor either
jointly or severally in the courts of any other jurisdictions.

     (c)  To the extent that Guarantor has or hereafter may acquire any immunity
from jurisdiction of any court or from any legal process (whether through
service or notice, attachment prior to judgment, attachment in aid of execution,
execution or otherwise) with respect to itself or its property, Guarantor hereby
irrevocably waives such immunity in respect of its obligations under this
Guaranty and the other Loan Papers.

     21.  THIS GUARANTY AND THE OTHER LOAN PAPERS COLLECTIVELY REPRESENT THE
FINAL AGREEMENT BY AND AMONG THE NOTEHOLDERS, THE ADMINISTRATIVE AGENT AND THE
GUARANTOR AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR
SUBSEQUENT ORAL AGREEMENTS OF THE NOTEHOLDERS, THE ADMINISTRATIVE AGENT AND THE
GUARANTOR.  THERE ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN THE NOTEHOLDERS, THE
ADMINISTRATIVE AGENT AND THE GUARANTOR.

     22.  GUARANTOR, FOR ITSELF, ITS SUCCESSORS AND ASSIGNS, AND THE NOTEHOLDERS
HEREBY IRREVOCABLY WAIVE, TO THE FULLEST EXTENT PERMITTED BY LAW, THEIR RIGHT TO
A JURY TRIAL, IN ANY LITIGATION ARISING OUT OF OR IN CONNECTION WITH THIS
GUARANTY OR ANY OF THE OTHER LOAN PAPERS.

     23.  THIS GUARANTY AND THE OTHER LOAN PAPERS HAVE BEEN EXECUTED AND
DELIVERED IN THE STATE OF TEXAS AND SHALL BE CONSTRUED IN ACCORDANCE WITH AND
GOVERNED BY THE LAWS OF THE STATE OF TEXAS AND THE LAWS OF THE UNITED STATES OF
AMERICA, EXCEPT TO THE EXTENT THAT THE LAWS OF ANY STATE IN WHICH ANY PROPERTY
INTENDED AS SECURITY FOR THE OBLIGATIONS IS LOCATED NECESSARILY GOVERN (A) THE
PERFECTION AND PRIORITY OF THE LIENS IN FAVOR OF ADMINISTRATIVE AGENT AND BANKS
WITH RESPECT TO SUCH PROPERTY, AND (B) THE EXERCISE OF ANY REMEDIES (INCLUDING
FORECLOSURE) WITH RESPECT TO SUCH PROPERTY.

     EXECUTED effective as of the date first above written.


                                                   GUARANTOR:

                                                   SOCO WATTENBERG CORPORATION,
                                                   a Delaware corporation
                                       6
<PAGE>
 
                                                   By:  ______________________
                                                   Its: ______________________
 
                                       7
<PAGE>
 
                                   EXHIBIT D
                                   ---------

                             REQUEST FOR BORROWING


     Reference is made to that certain Amended and Restated Credit Agreement
dated effective as of April 1, 1997 (as from time to time amended, the
"Agreement") by and among Patina Oil & Gas Corporation ("Patina"), Texas
 ---------                                               ------         
Commerce Bank National Association, as Administrative Agent, NationsBank of
Texas, N.A., as Documentary Agent, Wells Fargo Bank, N.A., CIBC, Inc. and Credit
Lyonnais New York Branch, as Co-Agents, and certain Banks as named and defined
therein. Terms which are defined in the Agreement and which are used but not
defined herein are used herein with the meanings given them in the Agreement.
Pursuant to the terms of the Agreement, Patina hereby requests a Borrowing in
the amount of $_____________ to be advanced on ______________________, _______.

     Patina requests that the Borrowing to be made hereunder shall be [AN
ADJUSTED BASE RATE BORROWING] [A EURODOLLAR BORROWING] and shall have the
Interest Periods all as set forth below:


     Type of Borrowing      Aggregate Amount      Interest Period
     -----------------      ----------------      ---------------


______________________    __________________    ________________

______________________    __________________    _________________

______________________    __________________    _________________


     Patina and the Authorized Officer of Patina signing this instrument hereby
certify that:

          (a)  Such officer is the duly elected, qualified and acting officer of
     Patina as indicated below such officer's signature hereto.

          (b)  The representations and warranties of Patina set forth in the
     Agreement and the Loan Papers delivered to Administrative Agent and Banks
     are true and correct on and as of the date hereof, with the same effect as
     though such representations and warranties had been made on and as of the
     date hereof or, if such representations and warranties are expressly
     limited to particular dates, as of such particular dates.  No material
     changes have occurred in the financial condition of Patina or any of its
     Subsidiaries since the date of the last financial reports delivered to
     Banks pursuant to Section 8.1 of the Agreement.
                       -----------                  

          (c)  There does not exist on the date hereof, any condition or event
     which constitutes a Default or Event of Default, nor will any such Default
     or Event of Default exist upon Patina's receipt and application of the
     proceeds requested hereby.  Patina will use the proceeds hereby requested
     in compliance with the applicable provisions of the Agreement.
<PAGE>
 
          (d)  Patina has performed and complied with all agreements and
     conditions in the Agreement required to be performed or complied with by
     Patina on or prior to the date hereof, and each of the conditions precedent
     to the Borrowing contained in the Agreement remain satisfied in all
     material respects.

          (e)  After giving effect to the Borrowing requested hereby, (i) the
     Outstanding Credit will not be in excess of the Borrowing Base on the date
     requested for the making of such Borrowing.

     IN WITNESS WHEREOF, this instrument is executed as of
_______________________,19___.


                              PATINA OIL & GAS CORPORATION,
                              a Delaware corporation



                              By:  ___________________________
                              Its: ___________________________

                                       2
<PAGE>
 
                                   EXHIBIT E
                                   ---------

                         REQUEST FOR LETTER OF CREDIT

     Reference is made to that certain Amended and Restated Credit Agreement
dated effective as of April 1, 1997 (as from time to time amended, the
"Agreement"), by and among Patina Oil & Gas Corporation ("Patina"), Texas
 ---------                                                ------         
Commerce Bank National Association, as Administrative Agent, NationsBank of
Texas, N.A., as Documentary Agent, Wells Fargo Bank, N.A., CIBC, Inc., and
Credit Lyonnais New York Branch, as Co-Agents, and certain other Banks as named
and defined therein.  Terms which are defined in the Agreement and which are
used but not defined herein are used herein with the meanings given them in the
Agreement.

     Pursuant to the terms of the Agreement, Patina hereby requests
________________ ("Issuer") to issue a Letter of Credit for the account of
                   ------                                                 
Patina or _______________________, a Restricted Subsidiary of Patina, as
follows:

     Type of Commitment:
     ------------------ 

     Requested Amount              $__________________________
     Requested Date of Issuance    ___________________________
     Requested Expiration Date     ___________________________
     Summary of Terms              ___________________________  
     (provide a brief description
     of conditions under which the
     drafts under such Letter of
     Credit are to be available)   ___________________________  
     Beneficiary (Name/Address)    ___________________________
                                   ___________________________ 
                                   ___________________________ 
                                   ___________________________ 
 
     Such Letter of Credit is more particularly described in the Letter of
Credit Application and Agreement of Issuer which is attached hereto.

     Patina and the Authorized Officer of Patina signing this instrument hereby
certify that:

          (a) Such officer is the duly elected, qualified and acting officer of
     Patina as indicated below such officer's signature hereto.

          (b) The representations and warranties of Patina set forth in the
     Agreement and the other Loan Papers delivered to Administrative Agent and
     Banks are true and correct on and as of the date hereof, with the same
     effect as though such representations and warranties had been made on and
     as of the date hereof, or if such representations and warranties are
     expressly limited to particular dates, as of such particular dates.  No
     material changes have
<PAGE>
 
     occurred in the financial condition of Patina since the date of the last
     financial reports delivered to Banks pursuant to Section 8.1 of the
     Agreement.

          (c) There does not exist on the date hereof any condition or event
     which constitutes a Default or Event of Default, nor will any such Default
     or Event of Default exist upon the issuance of the Letter of Credit
     requested hereby.  Patina will use the Letter of Credit solely for purposes
     permitted by the Agreement.

          (d) Patina has performed and complied with all agreements and
     conditions in the Agreement required to be performed or complied with by
     Patina on or prior to the date hereof, and each of the conditions precedent
     to the issuance of Letters of Credit contained in the Agreement remain
     satisfied in all material respects.

          (e) After the issuance of the Letter of Credit requested hereby, the
     sum of (A) the outstanding principal balance of the Loan, plus (B) the
     Letter of Credit Exposure, will not be in excess of the Borrowing Base in
     effect on the date requested for the issuance of such Letter of Credit.

     IN WITNESS WHEREOF, this instrument is executed as of ________________,
19__.

                                   PATINA OIL & GAS CORPORATION
                                   a Delaware corporation



                                   By:  ___________________________
                                   Its: ___________________________ 

                                       2
<PAGE>
 
                                   EXHIBIT F
                                   ---------

                                ROLLOVER NOTICE

     Reference is made to that certain Amended and Restated Credit Agreement
dated effective as of April 1, 1997 (as from time to time amended, the
"Agreement"), by and among Patina Oil & Gas Corporation ("Patina"), Texas
 ---------                                                ------         
Commerce Bank National Association, as Administrative Agent, NationsBank of
Texas, N.A., as Documentary Agent, Wells Fargo Bank, N.A., CIBC, Inc. and Credit
Lyonnais, as Co-Agents, and certain Banks as named and defined therein.  Terms
which are defined in the Agreement and which are used but not defined herein are
used herein with the meanings given them in the Agreement.

     [_]  Reference is hereby made to the existing Eurodollar Tranche
          outstanding under the Loan in the amount of $________ which is subject
          to an Interest Period expiring on _________________, 199__. Patina
          hereby requests that on the expiration of such Interest Period the
          portion of the principal of the Loan which is subject to such Tranche
          be made the subject of [_] an Adjusted Base Rate Tranche or [_] a
          Eurodollar Tranche having an Interest Period of ____ months.

     [_]  Patina hereby requests that on __________________, 199__, a portion of
          the principal of the Loan in the amount of $______ which is currently
          the subject of an Adjusted Base Rate Tranche be made the subject of a
          Eurodollar Tranche having an Interest Period of _____ months.

     Patina and the Authorized Officer of Patina signing this instrument hereby
certify that:

          (a) Such officer is the duly elected, qualified and acting officer of
     Patina as indicated below such officer's signature hereto;

          (b) There does not exist on the date hereof any condition or event
     which constitutes a Default or Event of Default; and

          (c) The representations and warranties of Patina set forth in the
     Agreement and the Loan Papers delivered to Administrative Agent and Banks
     are true and correct on and as of the date hereof, with the same effect as
     though such representations and warranties had been made on and as of the
     date hereof or, if such representations and warranties are expressly
     limited to particular dates, as of such particular dates.
<PAGE>
 
     IN WITNESS WHEREOF, this instrument is executed as of
_____________________, 19____.

                                   PATINA OIL & GAS CORPORATION
                                   a Delaware corporation



                                   By:  ___________________________
                                   Its: ___________________________ 
 
                                       2
<PAGE>
 
                                   EXHIBIT G
                                   ---------

                      ASSIGNMENT AND ASSUMPTION AGREEMENT


     THIS ASSIGNMENT AND ASSUMPTION AGREEMENT (this "Agreement") is dated
                                                     ---------           
_____________________, 199__, among __________________________ ("Assignor") and
                                                                 --------      
______________________________ ("Assignee") and Texas Commerce Bank National
                                 --------                                   
Association, as Administrative Agent for the Banks ("Administrative Agent").
                                                     --------------------   


                                  BACKGROUND.

     A.   Reference is made to that certain Amended and Restated Credit 
Agreement dated effective as of April 1, 1997 (as it may hereafter be amended 
or otherwise modified from time to time, being referred to as the "Credit 
                                                                   ------
Agreement") among Patina Oil & Gas Corporation, (the "Borrower"), the financial 
---------                                             --------               
institutions parties thereto as Banks thereunder, Administrative Agent,
NationsBank of Texas, N.A., as Documentary Agent, and Wells Fargo Bank, N.A.,
CIBC, Inc. and Credit Lyonnais, as Co-Agents. Unless otherwise defined, terms
are used herein as defined in the Credit Agreement.

     B.   This Agreement is made with reference to the following facts:

          (i)   Assignor is a Bank under and as defined in the Credit Agreement
     and, as such, presently holds a percentage of the rights and obligations of
     Banks under the Credit Agreement.

          (ii)  As of the date hereof, the Total Commitment is $__________,
     Assignor's Commitment is $______________, and Assignor's Commitment
     Percentage is _______%.

          (iii) As of the date hereof, Assignor's Commitment Percentage of the
     outstanding principal balance of the Loan is $_______________.

          (iv)  On the terms and conditions set forth below, Assignor desires to
     sell and assign to Assignee, and Assignee desires to purchase and assume
     from Assignor, as of the Effective Date (as defined below) ___________
     percent (_______%) (the "Assigned Percentage") of the Total Commitment
                              -------------------                          
     (such Assigned Percentage constitutes ________________ percent (________%)
     of Assignor's Commitment).
<PAGE>
 
                                  AGREEMENT.

     NOW, THEREFORE, Assignor and Assignee hereby agree as follows:

     1.  By this Agreement, and effective as of _____________, 199_ (which must
be at least five (5) Domestic Business Days after the execution and delivery of
this Agreement to Borrower and each Agent for acceptance), Assignor hereby sells
and assigns to Assignee, without recourse and, except as provided in paragraph 2
                                                                     -----------
of this Agreement, without representation and warranty, and Assignee hereby
purchases and assumes from Assignor, Assignor's rights and obligations under the
Credit Agreement, to the extent of the Assigned Percentage of the Loan, the
Letter of Credit Exposure, and the Commitment as in effect on the Effective
Date.

     2.  Assignor (a) represents and warrants that it is the legal and
beneficial owner of the interest being assigned by it hereunder and that such
interest is free and clear of any adverse claim; (b) makes no representation or
warranty and assumes no responsibility with respect to any statements,
warranties or representations made in or in connection with the Credit
Agreement, any other Loan Paper or any other instrument or document furnished
pursuant thereto, or with respect to the execution, legality, validity,
enforceability, genuineness, sufficiency or value of the Credit Agreement or any
other Loan Paper or any other instrument or document furnished pursuant thereto;
and (c) makes no representation or warranty and assumes no responsibility with
respect to the financial condition of Borrower or any Person or the performance
or observance by Borrower or any Person of any of its obligations under the Loan
Papers or any other instrument or document furnished pursuant thereto.

     3.  Assignee (a) confirms that it has received a copy of the Credit
Agreement, together with copies of the most recent financial statements
delivered to Assignor pursuant to Section 8 of the Credit Agreement, and such
                                  ---------                                  
other documents and information as it has deemed appropriate to make its own
credit analysis and decision to enter into this Agreement; (b) agrees that it
will, independently and without reliance upon the Administrative Agent,
Documentary Agent, Assignor or any other Bank and based on such documents and
information as it shall deem appropriate at the time, continue to make its own
credit decisions in taking or not taking action under the Credit Agreement and
the other Loan Papers; (c) appoints and authorizes Administrative Agent to take
such action as administrative agent on its behalf and to exercise such powers
under the Credit Agreement and the other Loan Papers as are delegated to
Administrative Agent by the terms thereof, together with such powers as are
reasonably incidental thereto; (d) agrees that it will perform in accordance
with their terms all of the obligations which, by the terms of the Credit
Agreement and the other Loan Papers, are required to be performed by it as a
Bank; (e) specifies, as its address for notice and Domestic Lending Office and
Eurodollar Lending Office, the offices set forth beneath its name on the
signature pages hereof, and (f) if Assignee is not organized under the laws of
the United States of America or one of its states, Assignee (a) represents and
warrants to Assignor, Administrative Agent and Borrower that (i) no Taxes are
required to be withheld by Administrative Agent or Borrower with respect to any
payments to be made to Assignee in respect of the Obligations and (ii) Assignee
has furnished to Administrative Agent and Borrower two (2) duly completed copies
of either U.S. Internal Revenue Service Form 4224, Form 1001, Form W-8, or other
form acceptable

                                       2
<PAGE>
 
to Administrative Agent that entitles Assignee to exemption from U.S. federal
withholding Tax on all interest payments under the Loan Papers, (b) covenants to
(i) provide Administrative Agent and Borrower a new form 4224, Form 1001, Form
W-8, or other form acceptable to Administrative Agent upon the expiration or
obsolescence of any previously delivered form according to applicable laws and
regulations, duly executed and completed by Assignee, and (ii) comply from time
to time with all applicable laws and regulations with regard to the withholding
Tax exemption, and (c) agrees that if any of the foregoing is not true or the
applicable forms are not provided, then Borrower and Administrative Agent
(without duplication) may deduct and withhold from interest payments under the
Loan Papers any United States federal income Tax at the maximum rate under the
Code.

     4.  Borrower acknowledges its obligations under the Credit Agreement, and
agrees, within five (5) Domestic Business Days after receiving an executed copy
of this Agreement to execute and deliver to Administrative Agent, in exchange
for the Note or Notes originally delivered to Assignor, new Notes to the order
of Assignor and Assignee in amounts equal to their respective amounts of the
Commitments.

     5.  As of the Effective Date, (a) Assignee shall be a party to the Credit
Agreement and, to the extent provided in this Agreement, have the rights and
obligations of a Bank thereunder, (b) Assignor shall, to the extent provided in
this Agreement, relinquish its rights and be released from its obligations under
the Credit Agreement and other Loan Papers, and (c) Assignor's Commitment
Percentage shall be ______%, and Assignee's Commitment Percentage shall be
_____%.

     6.  From and after the Effective Date, Administrative Agent shall make all
payments under the Credit Agreement in respect of the interest assigned hereby
(including, without limitation, all payments of principal, interest, fees and
other amounts with respect thereto) to Assignee. Assignor and Assignee shall
make all appropriate adjustments in payments under the Credit Agreement for
periods prior to the Effective Date directly between themselves.

     7.  This Agreement shall not become effective until (a) counterparts of
this Agreement are executed and delivered by Assignor and Assignee to Borrower,
Administrative Agent and each Bank, (b) Borrower, each Agent and each Bank
execute such counterparts, and (c) Administrative Agent receives a processing
fee of $2,500 from Assignor or Assignee.

     8.  This Agreement shall be governed by, and construed in accordance with,
the laws of the State of Texas, without reference to principles of conflict of
laws.

                                   ASSIGNOR:
                                   -------- 

                                   ____________________________


                                   By:_________________________
                                   Its:________________________
 
                                       3
<PAGE>
 
                                   ASSIGNEE:
                                   --------
Address for Notice:
------------------ 
                                   By:____________________________
____________________________       Its:___________________________

____________________________
____________________________
Attn:_______________________
Tel:________________________
Fax:________________________

Domestic Lending Office:
----------------------- 

____________________________ 
____________________________ 
____________________________ 
____________________________ 


Eurodollar Lending Office:
------------------------- 
 
____________________________ 
____________________________ 
____________________________ 
Attn:_______________________
Tel:________________________
Fax:________________________


                                   ADMINISTRATIVE AGENT:
                                   -------------------- 

                                   TEXAS COMMERCE BANK
                                   NATIONAL ASSOCIATION,
                                   as Administrative Agent


                                   By:____________________________  
                                   Its:___________________________


BORROWER:
-------- 

Accepted and approved this ____ day
of ________________________, 199_:

                                       4
<PAGE>
 
Patina Oil & Gas Corporation


By:____________________________  
Its:___________________________

                                       5
<PAGE>
 
                                   EXHIBIT H
                                   ---------

                       CERTIFICATE OF OWNERSHIP INTEREST

     This Certificate of Ownership Interest (this "Certificate") is executed and
                                                   -----------                  
delivered pursuant to that certain Amended and Restated Credit Agreement dated
effective as of April 1, 1997 (as amended from time to time, the "Agreement"),
                                                                  ---------   
by and among Patina Oil & Gas Corporation ("Patina"), Texas Commerce Bank
                                            ------                       
National Association, as Administrative Agent, NationsBank of Texas, N.A., as
Documentary Agent, Wells Fargo Bank, N.A., CIBC, Inc., and Credit Lyonnais, as
Co-Agents, and certain Banks as named and defined therein.  Unless otherwise
defined herein, all capitalized terms shall have the meanings given such terms
in the Agreement.

     In order to induce each Bank to enter into the Agreement and to make the
Loan thereunder, Patina hereby represents and warrants to each Bank that after
giving effect to the Merger, Patina holds good and valid title, beneficially and
of record, subject only to Permitted Encumbrances, to the working interests and
net revenue interests in and to all material oil and gas properties which are
set forth in the Current Reserve Report.

     Patina acknowledges and agrees that each Bank is relying on this
Certificate and the representations and warranties herein contained in entering
into the Agreement and committing to make Loan thereunder, and but for Patina's
execution and delivery of this Certificate, Banks would not enter into the
Agreement and commit to extend credit thereunder.

     Executed effective as of the 1st day of April, 1997.

                                   PATINA OIL & GAS CORPORATION,
                                   a Delaware corporation


                                   By:____________________________  
                                   Its:___________________________  
 
<PAGE>
 
                                  SCHEDULE 1

                            FINANCIAL INSTITUTIONS

<TABLE>
<CAPTION>
      =================================================================================================================
                         Banks                                   Commitment Amount              Commitment Percentage
                         -----                                              ------                         ----------
      -----------------------------------------------------------------------------------------------------------------
        <S>                                                      <C>                            <C>
        Texas Commerce Bank National Association                    $ 27,500,000                        19.643%
      -----------------------------------------------------------------------------------------------------------------
        NationsBank of Texas, N.A.                                  $ 25,000,000                        17.857%
      -----------------------------------------------------------------------------------------------------------------
        CIBC, Inc.                                                  $ 22,500,000                        16.071%
      -----------------------------------------------------------------------------------------------------------------
        Credit Lyonnais New York Branch                             $ 22,500,000                        16.071%
      -----------------------------------------------------------------------------------------------------------------
        Wells Fargo Bank, N.A.                                      $ 22,500,000                        16.071%
      -----------------------------------------------------------------------------------------------------------------
        Bank One, Texas, N.A.                                       $ 20,000,000                        14.287%
      -----------------------------------------------------------------------------------------------------------------
        Totals:                                                     $140,000,000                           100%
      =================================================================================================================
</TABLE> 
 
<TABLE> 
<CAPTION> 
====================================================================================================================================
          Banks                   Domestic Lending Office           Eurodollar Lending Office              Address for Notice
          -----                   -----------------------           -------------------------              ------------------
----------------------------------------------------------------------------------------------------------------------------------
<S>                             <C>                                <C>                                <C> 
Texas Commerce Bank National    2200 Ross Avenue, 3rd Floor        2200 Ross Avenue, 3rd Floor        2200 Ross Avenue, 3rd Floor
 Association                    Dallas, Texas 75201                Dallas, Texas 75201                Dallas, Texas 75201
                                Fax No. (214) 965-2389             Fax No. (214) 965-2389             Fax No. (214) 965-2389
----------------------------------------------------------------------------------------------------------------------------------
NationsBank of Texas, N.A.      901 Main Street, 64th Floor        901 Main Street, 64th Floor        901 Main Street, 64th Floor
                                Dallas, Texas 75202                Dallas, Texas 75202                Dallas, Texas 75202
                                Fax No. (214) 508-1285             Fax No. (214) 508-1285             Fax No. (214) 508-1285
----------------------------------------------------------------------------------------------------------------------------------
CIBC, Inc.                      2727 Paces Ferry Road, Suite 1200  2727 Paces Ferry Road, Suite 1200  909 Fannin, Suite 1200
                                Atlanta, GA 30339                  Atlanta, GA 30339                  Houston, Texas 77010
                                Fax No. (770) 319-4950             Fax No. (770) 319-4950             Fax No. (713) 650-3727
----------------------------------------------------------------------------------------------------------------------------------
Credit Lyonnais New York        1000 Louisiana, Suite 5360         1000 Louisiana, Suite 5360         1000 Louisiana, Suite 5360
 Branch                         Houston, Texas 77002               Houston, Texas 77002               Houston, Texas 77002
                                Fax No. (713) 751-0307             Fax No. (713) 751-0307             Fax No. (713) 751-0307
 
----------------------------------------------------------------------------------------------------------------------------------
Wells Fargo Bank, N.A.          633 Seventeenth Street,            633 Seventeenth Street,            633 Seventeenth Street,
                                3rd Floor, North Tower             3rd Floor, North Tower             3rd Floor, North Tower
                                Denver, Colorado 80270             Denver, Colorado 80270             Denver, Colorado 80270
                                Fax No. (303) 293-5120             Fax No. (303) 293-5120             Fax No. (303) 293-5120
----------------------------------------------------------------------------------------------------------------------------------
Bank One, Texas, N.A.           500 Throckmorton, 10th Floor       500 Throckmorton, 10th Floor       500 Throckmorton, 10th Floor
                                Ft. Worth, Texas 76102             Ft. Worth, Texas 76102             Ft. Worth, Texas 76102
                                Fax No. (817) 884-5622             Fax No. (817) 884-5622             Fax No. (817) 884-5622
----------------------------------------------------------------------------------------------------------------------------------
</TABLE> 
 
Administrative Agent - Address:
 
  1111 Fannin, 9th Floor        with a copy to:      2200 Ross Avenue, 3rd Floor
  Houston, Texas 77002                               Dallas, Texas 75201
  Attn: Gale Manning                                 Attn: Tim Perry
  Fax: (713) 750-3810                                Fax: (214) 965-2389

Documentary Agent - Address:

  901 Main Street, 64th Floor
  Dallas, Texas 75202
  Fax: (214) 508-1285
<PAGE>
 
                                  SCHEDULE 2

                                  INVESTMENTS

                                     None
<PAGE>
 
                                  SCHEDULE 3

                                     TAXES

1.   Audit of federal income tax return for 1993.  The claimed deficiency, which
     Borrower will contest vigorously, is approximately $1,064,000.

2.   Audit of Colorado income tax return for 1992.  A notice of deficiency for
     taxes of $136,760 has been received, which Borrower is appealing.  Borrower
     has established reserves for this deficiency, plus interest.

3.   Audit of Colorado sales and use taxes for 1990 through 1993.  A notice of
     deficiency has been received, which Borrower is appealing.  Borrower has
     established a reserve of $50,000.

4.   Audit of Colorado severance tax returns for 1991 through 1993.  A notice of
     deficiency for taxes of $478,363 has been received, which Borrower is
     protesting.  Borrower has established a reserve of $511,000.
<PAGE>
 
                                  SCHEDULE 4

                                 SUBSIDIARIES

<TABLE>
<CAPTION>
Name and                      Qualified         Issued and Outstanding          Options,
State of Incorporation        Jurisdictions     Stock and Holder                Warrants, etc.
----------------------        -------------     ----------------------          --------------
<S>                           <C>               <C>                             <C>
SOCO Wattenberg               Colorado          1,000                           None
Corporation                   Nebraska          Common
Delaware                                        Patina Oil & Gas Corporation
Patina Well Services, Inc.    Colorado          100                             None
Colorado                                        Patina Oil & Gas Corporation
</TABLE>
<PAGE>
 
                                  SCHEDULE 5

                                  OBLIGATIONS

                                     None
<PAGE>
 
                                  SCHEDULE 6

                                     DEBT

<TABLE>
<CAPTION>
     <S>                           <C>
                                   3/31/97
                                   -------
                                   (000's)
 
     Senior Bank Debt              87,450
 
     Senior Subordinated Notes     99,891
                                   ------
 
     Total Debt                   187,341
                                  =======
</TABLE>