EXHIBIT 2

                          PURCHASE AND SALE AGREEMENT

THIS AGREEMENT dated this 12th day of February, 1997, is between BURLINGTON
RESOURCES OIL & GAS COMPANY and GLACIER PARK COMPANY, each a Delaware
corporation (collectively, "Sellers"), with offices at 5051 Westheimer, Suite
1400, Houston, Texas 77056-2124, and VINTAGE PETROLEUM, INC. ("Buyer"), a
Delaware corporation, with offices at 4200 One Williams Center, Tulsa, Oklahoma
74172.

WHEREAS, Sellers desire to sell, and Buyer desires to purchase, upon and subject
to the terms and conditions hereinafter set forth, all of Sellers' right, title,
and interest in and to the following assets:

  (i)    The oil and gas leases, leasehold interests, overriding royalty
         interests, surface estates, term royalty interests, rights and
         interests attributable or allocable to the oil and gas leases or
         leasehold interests by virtue of pooling, unitization, communitization,
         and operating agreements, licenses, permits and other agreements, and
         other properties and interests described on Exhibit "A-1" (limited as
         to the interests, lands and depths indicated in the Exhibit) attached
         hereto (collectively, the "Leases"), together with Sellers' right,
         title and interest in and to the property and rights incident thereto,
         including, but not limited to, as of the Effective Time, rights in, to,
         and under leases, permits, rights-of-way, easements, licenses,
         farmouts, farmins, options, orders, and other contracts or agreements
         of a similar nature in any way relating thereto;

  (ii)   The wells, equipment, materials, fixtures and improvements on the
         Leases as of the Effective Time, appurtenant thereto or used or
         obtained in connection with the Leases or with the production,
         treatment, sale or disposal of hydrocarbons or waste produced therefrom
         or attributable thereto, and other appurtenances thereunto belonging
         (the "Equipment"); provided, however, Equipment shall not include
         leased equipment located on the Leases;

  (iii)  The unitization, pooling and operating agreements, and the units
         created thereby which relate to the Leases or interests described in
         Exhibit "A-1" or which relate to units or wells located on the Leases,
         including the units formed under orders, regulations, rules, and other
         official acts of the governmental authority having jurisdiction,
         together with any right, title, and interest created thereby in the
         Leases;

  (iv)   Gas purchase contracts and product purchase and sale agreements related
         to the Leases;

  (v)    Equipment leases and rental contracts, as more particularly described
         on Exhibit "A-2" attached hereto (to the extent the same are
         assignable);

                                                     Purchase and Sale Agreement
                                                                          Page 1

 
  (vi)   Gas gathering agreements, gas processing agreements, contracts and
         other agreements of a similar nature used primarily in connection with
         the Leases (to the extent the same are assignable);

  (vii)  Vehicles described in Exhibit "A-3" attached hereto; and

  (viii) Gathering systems described in Exhibit "A-4."

Sellers' interest in these assets is herein collectively referred to as the
"Interests"; provided, however, the Interests shall not include, and there is
excepted, reserved and excluded from this Agreement (x) the personal and real
property set forth in Exhibit "A-5" attached hereto (the "Excluded Interests")
and (y) the proprietary geophysical data described in the Data License Agreement
attached hereto as Exhibit "I".

NOW, THEREFORE, in consideration of the above recitals and of the covenants and
agreements herein contained, Sellers and Buyer agree as follows:

1. Purchase and Sale.  Subject to and upon all of the terms and conditions
   -----------------                                                      
   herein set forth, Sellers shall sell, transfer, assign, convey, and deliver
   the Interests to Buyer, and Buyer shall purchase, receive, pay for, and
   accept the Interests from Sellers, effective January 1, 1997, 7 a.m. local
   time, at the Leases (the "Effective Time").

2. Purchase Price and Performance Deposit.
   -------------------------------------- 

  (a) The purchase price for the Interests shall be $114,100,000.00 (the "Base
      Purchase Price"), subject to any applicable purchase price adjustment as
      provided for herein.

  (b) Buyer shall, upon execution of this Agreement, deliver to Sellers a
      performance deposit of $11,410,000.00 (the "Performance Deposit") to
      assure Buyer's performance hereunder.  At Closing, the Performance Deposit
      shall be a Buyer's credit against the Base Purchase Price. If this
      Agreement is terminated without a Closing, then the Performance Deposit
      shall be governed by the provisions of Section 27.

  (c) Sellers and Buyer agree that the Base Purchase Price shall be allocated
      among the Interests as set forth on Exhibit "B" for the purpose of (i)
      establishing a basis for certain taxes, (ii) giving notices of value to
      the owners of any preferential rights to purchase the Interests, and (iii)
      determining the value of a Title Defect or an Environmental Defect and
      handling those instances in which the Base Purchase Price is to be
      adjusted.

                                                     Purchase and Sale Agreement
                                                                          Page 2

 
3.  Title Defects.
    ------------- 

  (a) As used herein, the term "Defensible Title" shall mean, as to the
      Interests, such title held by Sellers, that, subject to and except for
      Permitted Encumbrances (as hereinafter defined):

      (i)    Entitle Sellers to receive not less than the "Net Revenue Interest"
             as set forth in Exhibit "B" of all oil, gas, and associated liquid
             and gaseous hydrocarbons produced, saved, and marketed from the
             Interests;

      (ii)   Obligates Sellers to bear costs and expenses relating to the
             maintenance, development, and operation of all wells located on the
             Interests in an amount not greater than the "Working Interest" set
             forth in Exhibit "B"; and

      (iii)  Is free and clear of any and all encumbrances, charges and liens.

  (b) As used herein, the term "Permitted Encumbrances" shall mean:

      (i)    Lessor's royalties, overriding royalties, production payments, and
             reversionary interests if the net cumulative effect of such burdens
             does not operate to reduce the Net Revenue Interest of any Interest
             to less than the Net Revenue Interest set forth in Exhibit "B";

      (ii)   Sales contracts covering oil, gas or associated liquid or gaseous
             hydrocarbons;

      (iii)  Preferential rights to purchase and required third party consents
             to assignments and similar agreements with respect to which (i)
             waivers or consents are obtained from the appropriate parties, or
             (ii) required notices have been given to the holders of such rights
             and the appropriate time period for asserting such rights has
             expired without an exercise of such rights;

      (iv)   Liens for taxes or assessments not due or not delinquent on the
             Closing Date;

      (v)    All rights to consent by, required notices to, filings with, or
             other actions by governmental agencies in connection with the sale
             or conveyance of oil and gas leases or interests therein or sale of
             production therefrom if the same are customarily obtained
             subsequent to such sale or conveyance;

      (vi)   Easements, rights-of-way, servitudes, permits, surface leases, and
             other rights in respect of surface operations on or over any of the
             Interests which do not operate to interfere with current operations
             on the Interests;

                                                     Purchase and Sale Agreement
                                                                          Page 3

 
      (vii)  Liens of operators relating to obligations not yet due or pursuant
             to which Sellers are not in default, and materialmen's, mechanics',
             repairmen's, or other similar liens or charges arising in the
             ordinary course of business incidental to construction, maintenance
             or operation of the Interests that are not such as to interfere
             with the operation, value or use of the Interests;

      (viii) The agreements set forth on Exhibit "F" attached hereto; and

      (ix)   Any Title Defects waived by Buyer pursuant to the terms of this
             Agreement.

  (c) The Interests shall be deemed to have a "Title Defect" if Sellers have
        less than Defensible Title to the Interests.

4.  Purchase Price Adjustments for Title Defects.
    -------------------------------------------- 

  (a) Buyer may, by delivery of written notice to Sellers of the existence of an
      alleged Title Defect, request reduction of the purchase price for the
      Interest affected. The Title Defect notice shall clearly indicate the
      nature of the Title Defect, the Interest to which it relates, an
      explanation of the Title Defect including the supporting legal theories,
      the allocated value of the Interest as to which all or some portion of
      which is affected by the Title Defect, and the amount by which Buyer
      believes the value of the affected Interest has been reduced because of
      the Title Defect, with the computation and information upon which Buyer's
      belief is based. In determining whether a portion of an Interest contains
      a Title Defect, it is the intent of the parties to include, when possible,
      only that portion of such Interest materially and adversely affected. If
      the value properly allocated to a Title Defect cannot be determined
      directly from Exhibit "B" because the Title Defect is included within, but
      does not totally comprise, the Interest to which the allocated value
      relates, Buyer and Sellers shall attempt, where feasible, to
      proportionately reduce the allocated value in Exhibit "B".

  (b) The Title Defect notice by Buyer shall be delivered to Sellers on or
      before 5:00 p.m., March 13, 1997, except that Buyer shall, to the extent
      reasonably practicable and in addition to the Title Defect notice, notify
      Sellers immediately as it becomes aware of Title Defects while performing
      its due diligence review of the Interests. In the event any such notice is
      not timely delivered, all Title Defects shall be deemed waived for all
      purposes and Buyer shall thereafter have no right to claim Title Defects;
      and in the event the Title Defect notice is timely delivered, all Title
      Defects not claimed in such notice shall be deemed waived for all
      purposes. Sellers shall have the right, but not the obligation, to attempt
      to cure any alleged Title Defect prior to Closing. In the event Sellers
      are unable or unwilling to cure an alleged Title Defect, Buyer and Sellers
      shall meet and use their reasonable efforts to agree on the validity of
      the claim of Title Defect and the amount of any required purchase price
      adjustment. In evaluating the significance of a fact, circumstance or
      condition for purposes of determining an alleged Title Defect, due
      consideration shall be given to the length of time that the particular
      Lease has been producing hydrocarbon substances and whether such fact,
      circumstance or

                                                     Purchase and Sale Agreement
                                                                          Page 4

 
      condition is of the type expected to be encountered in the area involved,
      and is usual and customarily acceptable to reasonable and prudent persons
      engaged in the business of the ownership, development, and operation of
      oil and gas properties with knowledge of all of the facts and appreciation
      of their legal significance.

  (c) In the event the parties cannot mutually agree on a purchase price
      adjustment for an alleged Title Defect, Buyer shall have the right to (i)
      proceed to Closing and accept the Interest with the alleged Title Defect
      with no purchase price adjustment, or (ii) terminate this Agreement as to
      the Interest affected by the alleged Title Defect and receive a purchase
      price adjustment for such Interest as set forth in Exhibit "B", or, where
      feasible, the proportionate allocated value.

  (d) There shall be no purchase price adjustment for Title Defects unless the
      aggregate total of all purchase price adjustments for Title Defects
      exceeds $200,000.00.

  (e) If Buyer shall determine that Sellers' net revenue interests in the
      Interests are greater than the Net Revenue Interests set forth on Exhibit
      "B", Buyer shall notify Sellers and Sellers shall be entitled to a
      mutually agreeable purchase price adjustment.

5.  Conditions of Closing by Sellers.  The obligation of Sellers to close is
    --------------------------------                                        
    subject to the satisfaction of the following conditions:

  (a) The representations of Buyer contained in Section 8 hereof are true in all
      material respects on and as of the Closing Date;

  (b) Buyer shall have delivered to Sellers a legal opinion rendered by counsel
      to the effect that (i) Buyer is a corporation validly existing and in good
      standing under the laws of the State of Delaware and has all requisite
      power and authority to execute and deliver this Agreement and to
      consummate the transactions contemplated hereby; (ii) the execution and
      delivery of, and consummation of the transactions contemplated by, this
      Agreement by Buyer have been duly authorized by all necessary action on
      the part of Buyer; and (iii) this Agreement has been duly executed and
      delivered by Buyer and constitutes a legal, valid and binding obligation
      of Buyer and is enforceable against Buyer in accordance with its terms,
      except that such enforcement may be subject to bankruptcy, insolvency,
      moratorium or similar laws affecting creditors' rights;

  (c) Adjustments to the purchase price in accordance with the provisions of
      Sections 4 and 13 hereof shall not have exceeded $11,410,000.00; and

                                                     Purchase and Sale Agreement
                                                                          Page 5

 
  (d) On or before Closing, Sellers shall have obtained the approval of the
      Board of Directors of its parent, Burlington Resources Inc., to consummate
      the transactions contemplated by this Agreement.

6.  Conditions of Closing by Buyer.  The obligation of Buyer to close is
    ------------------------------                                      
    subject to the satisfaction of the following conditions:
         
  (a) The representations of Sellers contained in Section 7 shall be true in all
      material respects on and as of the Closing Date;

  (b) Buyer and Sellers shall have adjusted the Base Purchase Price in
      accordance with the provisions of Sections 4, 13 and 15 hereof; and

  (c) Each Seller shall have delivered to Buyer a legal opinion rendered by such
      Seller's corporate counsel to the effect that (i) such Seller is a
      corporation validly existing and in good standing under the laws of the
      State of Delaware and have all requisite power and authority to execute
      and deliver this Agreement and to consummate the transactions contemplated
      hereby; (ii) the execution and delivery of, and consummation of the
      transactions contemplated by, this Agreement by Sellers has been duly
      authorized by all necessary action on the part of Sellers; and (iii) this
      Agreement has been duly executed and delivered by Sellers and constitutes
      a legal, valid and binding obligation of Sellers and is enforceable
      against Sellers in accordance with its terms, except that such enforcement
      may be subject to bankruptcy, insolvency, moratorium or similar laws
      affecting creditors' rights.

  (d) On or before February 21, 1997, Buyer shall have obtained the approval of
      its Board of Directors to consummate the transactions contemplated by this
      Agreement.

7.  Representations of Sellers.  Sellers represent to Buyer that:
    --------------------------                                   

  (a) Each Seller is a corporation validly existing and in good standing under
      the laws of the State of Delaware and is duly qualified to own its
      properties and assets and to carry on its business as now being conducted;

  (b) Subject to the condition set forth in Section 5(d) hereof, each Seller has
      the requisite power and authority to execute and deliver this Agreement
      and to consummate the transactions contemplated hereby, and the execution
      and delivery of this Agreement by each Seller and the consummation of the
      transactions contemplated hereby have been duly authorized;

  (c) Subject to the condition set forth in Section 5(d) hereof, this Agreement
      has been duly executed and delivered by each Seller and constitutes the
      valid and binding obligation of each Seller, enforceable against it in
      accordance with the terms hereof, subject to the 

                                                     Purchase and Sale Agreement
                                                                          Page 6

 
      effects of bankruptcy, insolvency, reorganization, moratorium, and similar
      laws affecting creditors' rights, and no other act, approval or proceeding
      on the part of each Seller or any other party is required to authorize the
      execution and delivery of this Agreement by each Seller or the
      consummation of the transactions contemplated hereby;
      
  (d) Subject to the condition set forth in Section 5(d) hereof, this Agreement,
      and the execution and delivery hereof by each Seller, does not and the
      consummation of the transactions contemplated hereby will not (i) conflict
      with or result in a breach of the charter or bylaws of either Seller or
      any other governing documents of either Seller, (ii) violate, or conflict
      with, or constitute a default under, or result in the creation or
      imposition of any security interest, lien or encumbrance upon any property
      or assets of each Seller under any mortgage, indenture or agreement to
      which it is a party or by which the Interests are bound, which violation,
      conflict or default might adversely affect the ability of each Seller to
      perform its obligation under this Agreement, or (iii) violate any statute
      or law or any judgment, decree, order, writ, injunction, regulation or
      rule of any court or governmental authority, which violation might
      adversely affect the ability of each Seller to perform its obligations
      under this Agreement;

  (e) Each Seller has incurred no liability, contingent or otherwise, for
      brokers' or finders' fees relating to the transactions contemplated by
      this Agreement for which Buyer shall have any responsibility whatsoever;

  (f) Each Seller is not a "foreign person" as defined in Section 1445 of the
      Internal Revenue Code of 1986 and in any regulations promulgated
      thereunder;

  (g) Except as set forth on Exhibit "E" attached hereto, to the best of each
      Seller's knowledge after a review of the Records, there are no claims,
      actions, suits or proceedings (including condemnation or similar
      proceedings) filed or threatened against the Interests or any portion
      thereof that would have a material adverse affect on the value or
      operation of the Interests; and

  (h) To the best of Sellers' knowledge, neither Sellers, nor the operator of
      those Interests operated by third parties, have violated any laws,
      statutes, regulations or orders applicable to any of the Interests or the
      operation thereof which violation (i) would have a material adverse affect
      on the value or operation of the affected Interests or (ii) has not been
      remedied.

  (i) None of the Interests are encumbered by take-or-pay or other similar
      arrangements with purchasers of oil or gas whereby either Seller is
      obligated (i) to deliver production without receiving payment therefor
      (ii) to repay monies received for production paid for but not taken; and

                                                     Purchase and Sale Agreement
                                                                          Page 7

 
      In those instances where Sellers' representations are made on the basis of
      "the best of Sellers' knowledge", such representations are made by Sellers
      on the basis of the actual knowledge of Sellers' personnel at or above the
      supervisory level, without any investigation. If such personnel have
      notice of material facts which should cause them to reasonably believe
      that an investigation should be conducted, then such personnel shall be
      deemed to have actual knowledge of the facts that would have been
      uncovered by such an investigation.

8.  Representations of Buyer.  Buyer represents to Sellers that:
    ------------------------                                    

  (a) Buyer is a corporation validly existing and in good standing under the
      laws of the State of Delaware and is duly qualified to own its properties
      and assets and to carry on its business as now being conducted;

  (b) Buyer has the requisite power and authority to execute and deliver this
      Agreement and to consummate the transactions contemplated hereby. The
      execution and delivery of this Agreement by Buyer and the consummation of
      the transactions contemplated hereby have been duly authorized;

  (c) This Agreement has been duly executed and delivered by Buyer and
      constitutes the valid and binding obligation of Buyer, enforceable against
      it in accordance with the terms hereof, subject to the effects of
      bankruptcy, insolvency, reorganization, moratorium, and similar laws
      affecting creditors' rights. No other act, approval or proceeding on the
      part of Buyer or any other party is required to authorize the execution
      and delivery of this Agreement by Buyer or the consummation of the
      transactions contemplated hereby;

  (d) This Agreement, and the execution and delivery hereof by Buyer, does not
      and the consummation of the transactions contemplated hereby will not (i)
      conflict with or result in a breach of the charter or bylaws of Buyer or
      any other governing documents of Buyer, or (ii) violate any statute or law
      or any judgment, decree, order, writ, injunction, regulation or rule of
      any court or governmental authority, which violation might adversely
      affect the ability of Buyer to perform its obligations under this
      Agreement;

  (e) Buyer possesses all required governmental licenses, permits, bonds,
      certificates, orders, and authorizations necessary to own or operate the
      Interests;

  (f) Buyer has, and will have on the Closing Date and thereafter, sufficient
      cash to enable it to make payment in immediately available funds of the
      purchase price when due and any other amounts to be paid by it hereunder;

  (g) Buyer is an experienced and knowledgeable investor in the oil and gas
      business. Buyer is not acquiring the Interests in connection with a
      distribution or resale thereof in violation of federal or state securities
      laws and the rules and regulations thereunder; and

                                                     Purchase and Sale Agreement
                                                                          Page 8

 
  (h) Buyer has incurred no liability, contingent or otherwise, for brokers' or
      finders' fees relating to the transactions contemplated by this Agreement
      for which Sellers shall have any responsibility whatsoever.

9. Claims.
   ------ 

  (a) "Claims" shall mean any and all claims, losses, damages, costs, expenses,
      diminutions in value, suits, causes of action or judgments of any kind or
      character with respect to any and all liabilities and obligations or
      alleged or threatened liabilities and obligations, including, but not
      limited to, any interest, penalty, and any attorneys' fees and other costs
      and expenses incurred in connection with investigating or defending any
      claims or actions, whether or not resulting in any liability.

  (b) "Environmental Law" shall mean any statute, rule, regulation or order of
      any governmental agency having jurisdiction over the Interests or Sellers
      pertaining to health, safety, or the environment.

  (c) An "Environmental Defect" shall mean a Claim attributable to or arising
      out of a violation (i) of any Environmental Law in effect on the Effective
      Time and applicable to conditions existing prior to the Closing Date, (ii)
      that is made known to Buyer prior to Closing, and (iii) to which prompt
      remedial or corrective action reasonably estimated to entail expenditures
      in excess of $50,000 either is required or would be undertaken by a
      prudent operator of oil and gas properties. For the sole purpose of
      determining if an Environmental Defect exceeds $50,000, occurrences
      (whether single or multiple) of different Environmental Defects shall be
      considered a single Environmental Defect with respect to the same
      individual site or facility.

  (d) An "Environmental Claim" shall mean a Claim attributable to or arising out
      of (i) a breach of the representation in Section 7(h) or (ii) a violation
      of any Environmental Law in effect on the Effective Time and applicable to
      conditions existing prior to the Closing Date, in either case, that is (x)
      that is made known to Buyer after the Closing and (y) to which prompt
      remedial or corrective action reasonably estimated to entail expenditures
      in excess of $50,000 either is required or would be undertaken by a
      prudent operator of oil and gas properties. For the sole purpose of
      determining if an Environmental Claim exceeds $50,000, occurrences
      (whether single or multiple) of different Environmental Claims shall be
      considered a single Environmental Claim with respect to the same
      individual site or facility.

10. Indemnities of Sellers.
    ---------------------- 

  (a) Sellers shall, to the fullest extent permitted by law, protect, defend,
      indemnify, and hold Buyer and its affiliates, including its directors,
      officers, employees, agents, and 

                                                     Purchase and Sale Agreement
                                                                          Page 9
 

 
      representatives of each of them, harmless from and against any and all
      Claims attributable to or arising out of (i) any act or omission by
      Sellers involving or related to the Interests occurring before the
      Effective Time, except as limited in (x), (y) and (z) below, (ii) the
      matters set forth on Exhibit "E" hereto, and (iii) the breach by Sellers
      of the representations contained in Section 7 hereof; provided, however,
      this indemnity is limited and shall not cover or include (x) matters
      pertaining to title to the Interests, all of which will be governed by
      Section 4 hereof, (y) any Claims with respect to any and all gas balancing
      liabilities and obligations or alleged or threatened liabilities and
      obligations, all of which will be governed by Section 14 hereof, or (z)
      any Claims with respect to any violation of Environmental Laws (regardless
      of the dollar amount in issue) waived pursuant to Section 13 hereof.

  (b) After Closing, any assertion by Buyer that Sellers are liable under the
      terms of the indemnities provided by Section 10(a)(i) or 10(a)(iii) must
      be made by Buyer in writing and must be given to Sellers on or prior to
      March 31, 1998; provided however, there shall be no time limitation for
      Claims related to the proper payment of (i) taxes, (ii) royalties,
      overriding royalties, and similar burdens on production, (iii) joint
      interest audits for periods prior to the Effective Time, or (iv) broker's
      or finder's fees. Any notice to Sellers shall state the facts known to
      Buyer that give rise to such notice in sufficient detail to allow Sellers
      to evaluate the assertion. All claims by Buyer for a breach of any of
      Seller's representations in Section 7 shall be asserted by Buyer under
      Section 10(a)(iii).

  (c) If a Claim arises for which Buyer intends to seek indemnity with respect
      thereto under Section 10(a)(i) or 10(a)(iii), Buyer shall notify Sellers
      of such Claim within 30 days after the date on which Buyer becomes aware
      of such Claim. Sellers shall have 30 days after receipt of such notice to
      undertake, conduct and control, through counsel of its own choosing and at
      its own expense, the settlement or defense thereof, and Buyer shall
      cooperate with Sellers in connection therewith. So long as Sellers have
      undertaken the defense of, and responsibility for, any such Claim and is
      reasonably contesting any such Claim in good faith, by appropriate
      proceedings (including the filing or posting of appeal bonds, supersedeas
      bonds and similar bonds), Buyer shall not pay or settle any such Claim.
      Buyer shall have the right to pay or settle any such Claim, provided that
      in such event it shall waive any right to indemnity by Sellers for such
      Claim. If Sellers do not notify Buyer within thirty (30) days after the
      receipt of Buyer's notice of a claim of indemnity hereunder that it elects
      to undertake the defense thereof, then Buyer shall have the right to
      contest, settle or compromise the Claim, but shall not thereby waive any
      right to indemnity therefor pursuant to this Section 10.

  (d) If any notice of a Claim which is an Environmental Claim given by Buyer to
      Sellers pursuant to this Section 10, Sellers' total liability hereunder
      for any and all such Environmental Claims shall be limited to
      $20,000,000.00, payable as follows:

                                                     Purchase and Sale Agreement
                                                                         Page 10

  
        (i)  the first $10,000,000.00 toward satisfaction of any such Claims
             shall be Sellers' sole responsibility; and

        (ii) the next $20,000,000.00 toward satisfaction of any such Claims
             shall be split equally between Sellers and Buyer.

  11. Assumption of Obligations and Indemnities of Buyer.
      -------------------------------------------------- 

    (a) As of the Effective Time, Buyer agrees to assume and perform any and all
        of the liabilities and obligations or alleged or threatened liabilities
        and obligations of Sellers (i) that relate to periods after the
        Effective Time and that arise under the agreements set forth on Exhibit
        "F," existing oil and gas leases, assignments, operating agreements,
        leases, permits, rights-of-way, licenses, easements, options, orders,
        gas purchase contracts, product purchase and sale agreements, gas
        gathering agreements, gas processing agreements, or any other agreements
        or contracts attributable to, affecting, or otherwise relating to the
        Interests, including, but not limited to, any and all liabilities and
        obligations to pay and deliver royalties, overriding royalties, non-
        participating royalties, and other burdens on production and (ii) in
        connection with or arising out of balancing of overproduction or
        underproduction from the Interests, whether relating to periods before
        or after the Effective Time. Additionally, as of the Effective Time,
        Buyer agrees to assume and perform any and all liabilities and
        obligations to comply with all laws and governmental regulations with
        respect to the Interests, including, but not limited to, the lawful
        plugging and abandonment of oil and gas wells and the restoration of the
        surface of the land, or any governmental request or other requirement to
        abandon any pipeline or facility or take any clean-up, remedial or other
        action with respect to the Interests, regardless of when the events
        occurred that caused such condition to exist or the obligation to arise.
        Without limitation of the foregoing, as of the Effective Time, Buyer
        agrees to assume and perform any and all of the obligations and
        liabilities or alleged or threatened liabilities and obligations of
        Sellers for any violation of Environmental Laws with respect to the
        Interests, regardless of when the events occurred that caused such
        condition to exist or the obligation to arise.

    (b) Buyer shall, to the fullest extent permitted by law, protect, defend,
        indemnify, and hold Sellers and its directors, officers, employees,
        agents, and representatives of each of them (the "Seller Parties"),
        harmless from and against any and all Claims attributable to or arising
        out of the following: (i) Buyer's ownership or operation of the
        Interests subsequent to the Effective Time; (ii) Buyer's assumption of
        any obligation or liability contained in this Section 11 (but only to
        the extent Sellers have not agreed to provide Buyer with indemnity
        pursuant to Section 10 hereof); (iii) the breach by Buyer of the
        representations contained in Section 8 hereof; (iv) the breach by Buyer
        of any of the agreements and covenants contained in this Agreement; and
        (v) any act, omission, event, condition, or circumstance involving or
        relating to the Interests occurring or existing before the Effective

                                                     Purchase and Sale Agreement
                                                                         Page 11

 
      Time that was not properly asserted by Buyer under Section 10(a) before
      the date specified in Section 10(b).

  (c) THE INDEMNIFICATION, RELEASE AND ASSUMPTION PROVISIONS PROVIDED FOR IN
      THIS AGREEMENT SHALL BE APPLICABLE WHETHER OR NOT THE LOSSES, COSTS,
      EXPENSES AND DAMAGES IN QUESTION AROSE SOLELY OR IN PART FROM THE GROSS,
      ACTIVE, PASSIVE, COMPARATIVE, OR CONCURRENT NEGLIGENCE, STRICT LIABILITY
      OR OTHER FAULT OF THE SELLER PARTIES.

12. Due Diligence Review.
    -------------------- 

  (a) Prior to Closing, Sellers, in Sellers' offices, will make available to
      Buyer and Buyer's authorized representatives for examination as Buyer may
      reasonably request, all lease files, land files, well files, product
      purchase and sale contracts, division order files, abstracts, title
      opinions, engineering, certain geophysical and geological data, reports,
      maps, logs, and well records contained in Sellers' files relating to the
      Interests (collectively the "Records"); provided, however, the Records
      shall not include (i) the geophysical data described in Exhibit "I," (ii)
      any other geophysical data that Sellers are restricted from transferring
      by third party agreements, or (iii) any information subject to third party
      confidentiality agreements for which a consent or waiver can not be
      secured by Sellers after reasonable efforts. Prior to Closing, Buyer, at
      Buyer's sole cost, may copy any portion of the Records as Buyer may
      reasonably request.

  (b) Sellers shall permit Buyer and Buyer's authorized representatives to
      consult with Sellers' employees during reasonable business hours and to
      conduct, at Buyer's sole risk and expense, wellsite inspections and
      inventories of the Interests that are operated by either Seller. During
      such inspections, Buyer shall have the right to review the Interests to
      determine the environmental condition of the Equipment and Lease premises.
      To the extent Buyer desires similar access to Sellers' non-operated
      Interests, Sellers shall assist Buyer in obtaining such access; provided,
      however, Buyer shall not contact the Operator of the non-operated
      Interests directly.

13. Purchase Price Adjustments for Environmental Defects.
    ---------------------------------------------------- 

  (a) Buyer may, by delivery of written notice to Sellers of the existence of an
      alleged Environmental Defect, request reduction of the purchase price for
      the Interest affected. The Environmental Defect notice shall clearly
      indicate the nature and a detailed description of the Environmental
      Defect, the Interest to which it relates, and the dollar amount which
      Buyer believes it would take to rectify or remediate the Environmental
      Defect.

                                                     Purchase and Sale Agreement
                                                                         Page 12

 
  (b) The Environmental Defect notice by Buyer shall be delivered to Sellers on
      or before March 13, 1997, except that Buyer shall, to the extent
      reasonably practicable and in addition to the Environmental Defect notice,
      notify Sellers immediately as it becomes aware of Environmental Defects
      while performing its due diligence review of the Interests. Sellers shall
      have the right, but not the obligation, to attempt to cure any alleged
      Environmental Defect prior to Closing. In the event Sellers are unable or
      unwilling to cure an alleged Environmental Defect, Buyer and Sellers shall
      meet and use their reasonable efforts to agree on the validity of the
      claim of the Environmental Defect and the amount of any required purchase
      price adjustment. Any violation of Environmental Law existing with respect
      to the Interests as of March 13, 1997, and known to Buyer on such date, or
      any conditions with respect to the Interests that might reasonably
      constitute a violation of Environmental Law existing as of March 13, 1997,
      and known to Buyer on such date, but not included in an Environmental
      Defect notice delivered by Buyer to Sellers on or before such date shall
      be deemed waived for all purposes, and no such violation or condition
      shall be considered an Environmental Defect or an Environmental Claim.

  (c) In the event the parties cannot mutually agree on the purchase price
      adjustment for an alleged Environmental Defect, Buyer shall have the right
      to (i) proceed to Closing and accept the Interest with the alleged
      Environmental Defect with no purchase price adjustment, or (ii) terminate
      this Agreement as to the Interest affected by the alleged Environmental
      Defect and receive a purchase price adjustment for such Interest as set
      forth in Exhibit "B", or, where feasible, the proportionate allocated
      value.

  (d) There shall be no purchase price adjustment for Environmental Defects
      unless the aggregate total of all Environmental Defects exceeds
      $200,000.00.

14. Gas Imbalances.  Sellers' estimate of the aggregate gas imbalance as of
    --------------                                                         
    the Effective Time for all the Interests is 243,643 MCF, cumulative working
    interest, overproduced, as more particularly set forth for each of the
    Interests on Exhibit "G". On or before March 19, 1997, Sellers shall provide
    Buyer with a revised gas imbalance schedule for all the Interests as of the
    Effective Time. There shall be a purchase price adjustment at Closing for
    the volumetric difference in the estimated and revised imbalance calculated
    on Sellers' net revenue interest at a price of $1.00 per MCF. To the extent
    that there is any difference between Sellers' actual aggregate gas imbalance
    as of the Effective Time and the imbalance position settled at Closing, then
    an adjustment shall be made at the $1.00 per net MCF rate in the Final
    Closing Statement. There shall be no further gas imbalance adjustments after
    the Post-Closing adjustment. In the event of a Title Defect affecting all or
    a portion of the Interests, the aggregate gas imbalance shown above shall be
    adjusted to take into account the affected Interest. Any purchase price
    adjustments for gas imbalances shall be made only on those Interests
    purchased by Buyer.

                                                     Purchase and Sale Agreement
                                                                         Page 13

 
15. Other Purchase Price Adjustments.
    -------------------------------- 

  (a) As used herein, the following terms have the meanings assigned:

      "Casualty Loss" shall mean, with respect to all or any portion of the
      Interests, any destruction by fire, blowout, storm or other casualty of
      all or any portion of the Interests between the Effective Time and
      Closing. Sellers shall promptly notify Buyer of any Casualty Loss of which
      Sellers become aware.

      "Preferential Purchase Right" shall mean any option, right or first
      refusal or similar preferential purchase right burdening a Lease.

      "Required Consent" shall mean any rights to consent to an assignment or
      transfer of a Lease, other than filings with governmental entities or
      notices to third parties customarily obtained subsequent to a sale or
      transfer, where the failure to receive such consent could reasonably
      render the transfer of such Lease to Buyer void or voidable.

  (b) If any Casualty Loss occurs prior to Closing to any of the Interests and
      such Casualty Loss may be repaired prior to Closing and, when repaired,
      the value of such Interests shall not be materially diminished, then
      Sellers may repair such Casualty Loss prior to Closing at Sellers' cost
      and shall notify Buyer of such election. In the event Sellers (i) elect to
      repair such Casualty Loss and such repair is not completed prior to
      Closing or the repair completed by Sellers do not cause the value of such
      Interests to be substantially the same as such value prior to the Casualty
      Loss, or (ii) is unable or unwilling to repair the Casualty Loss, then
      Buyer shall have the right to (x) proceed to Closing and accept the
      Interest with the Casualty Loss with no purchase price adjustment, or (y)
      terminate this Agreement as to the Interest affected by the Casualty Loss
      and receive a purchase price adjustment for such Interest as set forth in
      Exhibit "B", or where feasible, the proportionate allocated value.

  (c) Sellers shall promptly give notices to all third parties holding any
      Preferential Purchase Right known to Sellers or identified to Sellers by
      Buyer prior to Closing. Sellers shall use all reasonable efforts, but
      without obligation to incur any unreasonable cost or expense, to obtain
      waivers of, or to comply with, such Preferential Purchase Right prior to
      Closing. If a Preferential Purchase Right is exercised prior to Closing,
      the purchase price shall be reduced by the amount set forth in Exhibit
      "B"for the affected Interest, or where applicable and possible, the
      proportionate allocated value, and Sellers shall convey the affected
      Interest to the holder of such right and be entitled to all amounts paid
      by such holder. If a Preferential Purchase Right is exercised after
      Closing, Buyer shall convey the affected Interest to the holder of such
      right and be entitled to receive all amounts paid by such holder.

                                                     Purchase and Sale Agreement
                                                                         Page 14

 
  (d) Sellers shall promptly give notices to all third parties holding any
      Required Consents known to Sellers or identified to Sellers by Buyer prior
      to Closing. Sellers shall use all reasonable efforts, but without
      obligation to incur any unreasonable cost or expense, to obtain such
      Required Consents. Unless waived by Buyer, if a Required Consent is not
      obtained prior to Closing, the purchase price shall be reduced by the
      amount set forth in Exhibit "B"for the affected Interest, or where
      applicable and possible, the proportionate allocated value, and such
      Interest shall be excluded from the purchase and sale under this
      Agreement. Any Required Consent waived by Buyer shall be deemed a
      Permitted Encumbrance.

16. Confidentiality.  All Records, and all other confidential data provided to
    ---------------                                                           
    Buyer, whether before or after the date of this Agreement, and all title
    matters and environmental reports prepared by Buyer or Buyer's
    representatives relating to the Interests, shall be treated by Buyer as
    strictly confidential, and shall not be disclosed to any person, firm or
    corporation without the prior written consent of Sellers. In the event this
    purchase and sale does not close, this covenant shall survive termination of
    this Agreement and Buyer shall promptly return all copies of the Records in
    its possession; and in the event the sale closes, this covenant shall
    terminate at Closing.

17. DISCLAIMERS.  THE INSTRUMENTS OF CONVEYANCE EXECUTED PURSUANT HERETO SHALL
    -----------                                                               
    BE EXECUTED WITHOUT ANY REPRESENTATION, WARRANTY OR COVENANT OF TITLE OF ANY
    KIND OR NATURE, EITHER EXPRESS, IMPLIED OR STATUTORY; PROVIDED, HOWEVER,
    SELLERS SHALL SPECIALLY WARRANT AND AGREE TO DEFEND THE TITLE TO THE
    INTERESTS AGAINST THE LAWFUL CLAIMS AND DEMANDS OF ALL PERSONS OR ENTITIES
    CLAIMING THE SAME OR ANY PART THEREOF BY, THROUGH OR UNDER SELLERS, BUT NOT
    OTHERWISE. THE INTERESTS ARE BEING CONVEYED AND ASSIGNED TO AND ACCEPTED BY
    BUYER IN ITS "AS IS, WHERE IS" CONDITION AND STATE OF REPAIR, AND WITH ALL
    FAULTS AND DEFECTS, WITHOUT ANY REPRESENTATION, WARRANTY OR COVENANT OF ANY
    KIND OR NATURE, EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT NOT LIMITED
    TO, WARRANTIES OF MARKETABILITY, QUALITY, CONDITION, CONFORMITY TO SAMPLES,
    MERCHANTABILITY, AND/OR FITNESS FOR A PARTICULAR PURPOSE, ALL OF WHICH ARE
    EXPRESSLY DISCLAIMED BY SELLERS AND WAIVED BY BUYER. THE INTERESTS HAVE BEEN
    USED FOR OIL AND GAS DRILLING AND PRODUCTION, PIPELINE, TRANSPORTATION,
    STORAGE AND RELATED OPERATIONS. PHYSICAL CHANGES IN THE INTERESTS AND IN THE
    LANDS BURDENED THEREBY MAY HAVE OCCURRED AS A RESULT OF SUCH USES. THE
    INTERESTS MAY ALSO INCLUDE BURIED PIPELINES AND OTHER EQUIPMENT, THE
    LOCATIONS OF WHICH MAY NOT BE KNOWN BY SELLERS OR READILY APPARENT BY A
    PHYSICAL INSPECTION OF THE INTERESTS. IT IS UNDERSTOOD AND AGREED THAT BUYER
    SHALL HAVE INSPECTED PRIOR TO CLOSING (OR SHALL BE DEEMED

                                                     Purchase and Sale Agreement
                                                                         Page 15

 
    TO HAVE WAIVED ITS RIGHT TO INSPECT) THE LEASES, THE EQUIPMENT AND THE
    ASSOCIATED PREMISES AND SATISFIED ITSELF AS TO THEIR PHYSICAL AND
    ENVIRONMENTAL CONDITION, BOTH SURFACE AND SUBSURFACE, AND THAT BUYER SHALL
    ACCEPT ALL OF THE SAME IN ITS "AS IS, WHERE IS" CONDITION AND STATE OF
    REPAIR, AND WITH ALL FAULTS AND DEFECTS, INCLUDING, BUT NOT LIMITED TO, THE
    PRESENCE OF NATURALLY OCCURRING RADIO ACTIVE MATERIAL (NORM) AND MAN-MADE
    MATERIAL FIBERS (MMMF). IN ADDITION, SELLERS AND ITS ADVISORS, MORGAN
    STANLEY & CO. AND RANDALL & DEWEY, INC., MAKES NO REPRESENTATION, COVENANT
    OR WARRANTY, EXPRESS, IMPLIED OR STATUTORY, AS TO THE ACCURACY OR
    COMPLETENESS OF ANY DATA OR RECORDS DELIVERED TO BUYER WITH RESPECT TO THE
    INTERESTS, OR CONCERNING THE QUALITY OR QUANTITY OF HYDROCARBON RESERVES, IF
    ANY, ATTRIBUTABLE TO THE INTERESTS, OR THE ABILITY OF THE INTERESTS TO
    PRODUCE HYDROCARBONS, OR THE PRICES WHICH BUYER IS OR WILL BE ENTITLED TO
    RECEIVE FOR ANY SUCH HYDROCARBONS.

18. DTPA Waiver.  TO THE EXTENT APPLICABLE TO THE TRANSACTIONS CONTEMPLATED BY
    -----------                                                               
    THIS AGREEMENT, BUYER HEREBY WAIVES ITS RIGHTS UNDER THE PROVISIONS OF THE
    TEXAS DECEPTIVE TRADE PRACTICES ACT, CHAPTER 17, SUBCHAPTER E, SECTIONS
    17.41 THROUGH 17.63, INCLUSIVE (OTHER THAN SECTION 17.555, WHICH IS NOT
    WAIVED), OF THE TEXAS BUSINESS & COMMERCIAL CODE (A LAW THAT GIVES CONSUMERS
    SPECIAL RIGHTS AND PROTECTIONS). AFTER CONSULTATION WITH AN ATTORNEY OF ITS
    CHOICE, BUYER VOLUNTARILY CONSENTS TO THIS WAIVER.

19. Preclosing and Closing. Sellers and Buyer shall meet on or before March
    ----------------------                                                 
    21, 1997, at the offices of Sellers at 5051 Westheimer, Suite 1400, Houston,
    Texas, or at such other time and place as Sellers and Buyer may mutually
    agree in writing, to complete and execute, but not deliver, the closing
    documents for the transaction contemplated hereunder. The closing documents
    shall be held by Sellers until April 1, 1997. On April 1, 1997, Buyer shall
    deliver the Closing Amount to Sellers as provided in Section 20(l) below and
    Sellers shall deliver the closing documents to the appropriate parties (the
    "Closing" or the "Closing Date").                         

20. Transactions at Preclosing and Closing.
    -------------------------------------- 

  (a) Sellers shall execute, acknowledge, and deliver to Buyer the instruments
      of conveyance in the forms as set forth in Exhibits "C-1" through "C-8"
      hereto conveying the Interests;

  (b) Sellers and Buyer shall execute and deliver a Preliminary Closing
      Statement that shall set forth the Base Purchase Price and each adjustment
      and the calculation of such adjustments used to determine such amount (the
      "Closing Amount") in the form as set forth in Exhibit "D" hereto;

                                                     Purchase and Sale Agreement
                                                                         Page 16

 
  (c) Sellers shall deliver to Buyer the Records (but shall be authorized to
      keep a copy of the Records);

  (d) Sellers and Buyer shall execute, acknowledge and deliver mutually
      agreeable transfer orders or letters-in-lieu prepared by the Buyer,
      directing all purchasers of production to make future payments of proceeds
      attributable to production from the Interests to Buyer;

  (e) Sellers shall deliver to Buyer (i) a certificate stating that the
      representations of Sellers contained in Section 7 hereof are true as of
      the Closing Date, and (ii) a "non-foreign person" affidavit in the form as
      set forth in Exhibit "H" hereto;

  (f) Sellers shall deliver to Buyer the legal opinion referenced in Section
      6(c) hereof;

  (g) Buyer shall deliver to Sellers a certificate stating that the
      representations of Buyer contained in Section 8 hereof are true as of the
      Closing Date;

  (h) Buyer shall deliver to Sellers the legal opinion referenced in Section
      5(b) hereof;

  (i) Buyer shall deliver to Sellers a complete copy of Buyer's environmental
      assessment, including, but not limited to, reports, data, valuation,
      assessments and conclusions;

  (j) Sellers shall deliver to Buyer possession of the Interests, subject to any
      applicable operating agreement or other related agreement affecting the
      Interests;

  (k) Sellers and Buyer shall execute the Data License Agreement in the form as
      set forth in Exhibit "I" hereto; and

  (l) Buyer shall deliver to Sellers cash by wire transfer in the amount of the
      Closing Amount to the following account:

              Bank:                 Mellon Bank, Pittsburgh, PA.
              ABA/Routing Number:   043-000-261
              Account:              104-9050
              For Credit To:        Burlington Resources Services Inc.

21. Further Assurance.  Incidental and subsequent to Closing, each of the
    -----------------                                                    
    parties shall execute, acknowledge, and deliver to the other such further
    instruments, and take such other actions as may be reasonably necessary to
    carry out the provisions of this Agreement.

                                                     Purchase and Sale Agreement
                                                                         Page 17

 
22. Post-Closing Adjustments.  On or before November 1, 1997, the parties
    ------------------------                                             
    shall undertake to agree with respect to the adjustments or payments that
    were not finally determined as of Closing, and the amount due from Buyer or
    Sellers, as the case may be, pursuant to the Post-Closing adjustment. On or
    before October 1, 1997, Sellers shall provide Buyer with a Final Closing
    Statement setting forth the Post-Closing adjustments. Sellers shall provide
    Buyer access to such of Sellers' records as may be reasonably necessary to
    verify the Post-Closing adjustments. Payment by Buyer or Sellers shall be
    made in immediately available funds within five (5) days of agreement. If
    the Final Closing Statement has not been agreed upon on or before the date
    set forth herein, either party may seek to enforce any rights it claims
    pursuant to this Agreement.

23. Proration of Taxes.  All ad valorem taxes, real property taxes, and
    ------------------                                                 
    similar obligations with respect to the tax period in which the Effective
    Time occurs (the "current tax period") shall be apportioned between Sellers
    and Buyer as of the Effective Time based on an estimate of the immediately
    preceding tax period assessment, and the Base Purchase Price shall be
    reduced at Closing by the amount of such estimated taxes owed by Sellers for
    that portion of the current tax period prior to the Effective Time.

24. Proceeds.
    -------- 

  (a) All proceeds, including, but not limited to, proceeds held in suspense or
      escrow and proceeds received after the Effective Time for oil produced and
      held in storage on the Leases but not sold as of the Effective Time,
      attributable to the Interests and accruing to the period prior to the
      Effective Time shall belong to Sellers. Sellers shall retain overhead
      charges and rates received by Sellers in its capacity as Operator under
      any operating agreement or COPAS accounting procedure attributable to the
      Interests through the end of the month in which Closing occurs.

  (b) All proceeds attributable to the Interests and accruing to the period on
      and after the Effective Time shall belong to Buyer. In the event Sellers
      has received proceeds belonging to Buyer after the Effective Time, Sellers
      will account to Buyer for such proceeds at the same price Sellers received
      for the production in accordance with its existing product purchase and
      sale contracts.

25. Employees.  Buyer intends to continue to operate the Interests in the
    ---------                                                            
    ordinary course of business. Buyer shall interview for employment all
    employees of Sellers listed on Exhibit "J". Buyer may, in its sole
    discretion, offer employment to some or all of such employees.

26. Hart-Scott-Rodino Filing.  This Agreement is subject in all respects to
    ------------------------                                               
    and conditioned upon compliance by the parties of the Hart Scott Rodino
    Antitrust Improvements Act of 1976, and rules and regulations promulgated
    pursuant thereto (the "Act"), to the extent that the Act is applicable to
    the transactions contemplated by this Agreement. The parties shall make such
  
                                                     Purchase and Sale Agreement
                                                                         Page 18

 
    filings within five (5) business days after execution of this Agreement, and
    provide such information to the Federal Trade Commission and their attorneys
    as are required in connection with the Act as soon as practicable after a
    request therefor.

27. Failure to Close.  Subject to the other provisions of this Section, if all
    ----------------                                                          
    of the conditions to Closing set forth in Sections 5, 6 and 26 hereof have
    not been satisfied or waived by the respective parties on or before April
    30, 1997 (or such later date as hereafter may be mutually agreed upon by the
    parties in writing), this Agreement shall terminate automatically, and no
    party hereto shall have any further obligations or any liability to the
    other party pursuant to this Agreement; provided, however, that nothing
    herein shall relieve any party from liability for its willful failure to
    satisfy any conditions to Closing required to be satisfied by it. If the
    conditions to Buyer's obligations to close as set forth in Section 6 hereof
    have not been satisfied or waived by such date, or in the event this
    transaction is not consummated due to the conditions of Closing contained in
    Sections 5(c) or 5(d) or 26 hereof, the Performance Deposit shall be
    returned to Buyer. If this transaction is not consummated on such date for
    any reason other than the conditions of Closing by Sellers contained in
    Sections 5(c) or 5(d), Sections 6(a), 6(b), or 6(c) hereof and 26 hereof,
    Sellers may retain the Performance Deposit, as agreed liquidated damages and
    not as a penalty, it being agreed that actual damages would be difficult to
    ascertain and that such amount is reasonable Upon any termination of this
    Agreement, Sellers shall be free immediately to enjoy all rights of
    ownership of the Interests and to sell, transfer, encumber or otherwise
    dispose of the Interests to any party without any restriction under this
    Agreement.

28. Use of Sellers' Names.  Buyer agrees that, as soon as practicable after
    ---------------------                                                  
    Closing, it will remove or cause to be removed the names and marks
    Burlington Resources, Meridian Oil, El Paso Production, Glacier Park, or
    Southland Royalty, where and if they exist, and all variations and
    derivatives thereof and logos relating thereto from the Interests and will
    not thereafter make any use whatsoever of such names, marks, and logos.

29. Operations Pending Closing.  Sellers shall operate the Interests operated
    --------------------------                                               
    by either Seller using the same standard of care (i) as an ordinary prudent
    operator, or (ii) if the Interests are subject to an operating agreement, as
    imposed on the "Operator" under such joint operating agreement, in either
    case, until Closing, or such later time as any applicable joint operating
    agreement may require, when such operation shall be turned over to, and
    become the responsibility of, Buyer. During the period from the date of this
    Agreement to Closing, Sellers shall (i) consult with Buyer with respect to
    all AFE's over $100,000.00 net to the interests of Sellers which are
    received by Sellers with respect to any Interest, and consult with Buyer
    with respect to all material decisions to be made with respect to the
    Interests, including, without limitation, the incurring of costs for
    discretionary expenditures for operations in excess of $100,000.00 net to
    the interest of Sellers for which AFE's are not prepared, (ii) operate the
    Interests in accordance with the terms and conditions of all applicable
    contracts, laws and regulations, and (iii) not transfer, sell, hypothecate,
    encumber, abandon or otherwise dispose of any material portion of the
    Interests (other than the sale of production in the ordinary course of
    business) or as required

                                                     Purchase and Sale Agreement
                                                                         Page 19

 
    in connection with the exercise of third parties of preferential rights to
    purchase any of the Interests without the express written consent of Buyer.

30. Operations.  Should Sellers presently operate any Interest, Sellers make
    ----------                                                              
    no representation, warranty or covenant that the Buyer will become operator
    of any or all of the Interests. Buyer acknowledges that operations will be
    governed by the applicable operating agreements or other related agreements
    affecting the Interests.

31. Occasional Sale.  Sellers and Buyer believe that this purchase and sale of
    ---------------                                                           
    the Interests constitutes an isolated or occasional sale and is not subject
    to sales tax; provided, however, if any sales, transfers, use taxes or other
    similar taxes are due or should hereafter become due (including penalty and
    interest thereon) by reason of this transaction, Buyer shall timely pay and
    solely bear all such taxes.

32. Recording Documents.  Buyer shall pay all documentary, filing, and
    -------------------                                               
    recording fees incurred in connection with the filing and recording of the
    instruments of conveyance. As soon as practicable after Closing, Buyer shall
    provide Sellers with recorded copies of all documents conveying the
    Interests to Buyer.

33. Notices.  All notices hereunder shall be sufficiently given for all
    -------                                                            
    purposes hereunder if in writing and delivered personally, or to the extent
    receipt is confirmed by the party charged with notice, sent by documented
    overnight delivery service, by United States Mail, telecopy, telefax or
    other electronic transmission service to the appropriate address or number
    as set forth below. Notices to Sellers or Buyer shall be addressed to:

            SELLERS                        BUYER
 
    Burlington Resources Oil &     Vintage Petroleum, Inc.
      Gas Company                  4200 One Williams Center
    5051 Westheimer                Tulsa, Oklahoma 74172
    Suite 1400                     Attn: Robert W. Cox
    Houston, Texas 77056-2124      Fax: 918-588-9704
    Attn: Kent Beers
    Fax:  713-624-9640

34. Entire Agreement.  This instrument states the entire agreement
    ----------------                                              
    and supersedes all prior agreements (except any prior Confidentiality
    Agreement between the Buyer and Sellers) between the parties concerning the
    subject matter hereof. This Agreement may be supplemented, altered, amended,
    modified or revoked by writing only, signed by both parties.

                                                     Purchase and Sale Agreement
                                                                         Page 20

 
35. Counterpart. This Agreement may be executed by Buyer and Sellers in any
    -----------
    number of counterparts, each of which shall be deemed an original
    instrument, but all of which together shall constitute one and the same
    instrument.

36. Time of Essence.  Time is of the essence in this Agreement.
    ---------------                                            

37. Announcements. Sellers and Buyer shall consult with each other prior to the
    release of any press releases and other announcements concerning this
    Agreement or the transactions contemplated hereby. Any press release or
    other announcements will be at a time and in a form reasonably acceptable to
    Sellers and Buyer.

38. Waiver. Any of the terms, provisions, covenants, representations, warranties
    ------
    or conditions hereof may be waived only by a written instrument executed by
    the party waiving compliance. The failure of any party at any time or times
    to require performance of any provisions hereof shall in no manner affect
    such party's right to enforce the same. No waiver of any of the provisions
    of this Agreement shall be deemed or shall constitute a waiver of any other
    provisions hereof (whether or not similar), nor shall such waiver constitute
    a continuing waiver unless otherwise expressly provided.

39. Survival of Representations and Covenants. All representations and covenants
    -----------------------------------------
    of the parties to the extent not fully performed or waived prior to Closing
    shall survive the Closing other than those contained in Sections 4, 5, 6,
    and 13 hereof. Claims for a breach of a representation or covenant covered
    by the provisions of Sections 10 and 11 shall be governed exclusively by the
    provisions of such Sections.

40. Reliance. Prior to executing and/or closing this Agreement, Buyer has been
    --------
    afforded an opportunity to (i) examine the Interests and such materials as
    it has requested to be provided to it by Sellers, (ii) discuss with
    representatives of Sellers such materials and the nature and operation of
    the Interests and (iii) investigate of the condition, including subsurface
    condition, of the Interests. In entering into and closing this Agreement,
    Buyer has relied solely on the express representations and covenants of
    Sellers in this Agreement, its independent investigation of, and judgment
    with respect to, the Interests, and the advice of its own legal, tax,
    economic, environmental, engineering, geological and geophysical advisors,
    and not on any comments or statements of Sellers or any representatives or
    agents of, or consultants or advisors engaged by, Sellers.

41. Governing Law. This Agreement and the rights and obligations of the parties
    -------------
    hereto shall be governed, construed, and enforced in accordance with the
    laws of the State of Texas. The parties agree that any litigation relating
    directly or indirectly to this Agreement must be brought before and
    determined by a court of competent jurisdiction within the State of Texas,
    except to the extent the laws of another jurisdiction mandatorily apply.

                                                     Purchase and Sale Agreement
                                                                         Page 21

 
42. Legal Fees. The prevailing party in any legal proceeding brought under or to
    ----------
    enforce this Agreement shall be additionally entitled to recover court costs
    and reasonable attorneys' fees from the non-prevailing party.

43. Agreement for the Parties' Benefit Only. This Agreement is not intended to
    ---------------------------------------
    confer upon any person not a party hereto any rights or remedies hereunder,
    and no person, including, but not limited to, those persons affected by
    Section 25 hereof, other than the parties hereto is entitled to rely on any
    representation, covenant, or agreement contained herein.

44. Severability. If any term or other provision of this Agreement is invalid,
    ------------
    illegal or incapable of being enforced by any rule of law or public policy,
    all other conditions and provisions of this Agreement shall nevertheless
    remain in full force and effect so long as the economic or legal substance
    of the transactions contemplated hereby is not affected in any adverse
    manner to any party. Upon such determination that any term or other
    provision is invalid, illegal or incapable of being enforced, the parties
    hereto shall negotiate in good faith to modify this Agreement so as to
    effect the original intent of the parties as closely as possible in an
    acceptable manner to the end that the transactions contemplated hereby are
    fulfilled to the extent possible.

45. Binding Effect; Assignment. All the terms, provisions, covenants,
    --------------------------
    representations, and conditions of this Agreement shall be binding upon and
    inure to the benefit of and be enforceable by the parties hereto and their
    respective successors; provided, however, this Agreement or any portion
    thereof and the rights and obligations hereunder shall not be assignable or
    delegable by any party without the express prior written consent of the non-
    assigning or non-delegating party.

46. Enforcement. Should Buyer or Sellers default in the performance of this
    -----------
    Agreement, the non-defaulting party shall be entitled to enforce specific
    performance of this Agreement, or exercise any other right or remedy it may
    have at law or in equity by reason of such default.

47. Like Kind Exchange - Internal Revenue Code (S)1031. Buyer agrees to
    --------------------------------------------------
    cooperate with and assist Sellers as reasonably requested to enable Sellers
    to comply with the provisions of Section 1031 of the Internal Revenue Code
    and related provisions thereto.

                                                     Purchase and Sale Agreement
                                                                         Page 22

 
EXECUTED as of the date first above mentioned.


                                     SELLERS:

                                     BURLINGTON RESOURCES OIL & GAS COMPANY



                                     By: /s/ Mark E. Ellis
                                         ---------------------------------------

                                     Its:  Vice President
                                           -------------------------------------


                                     GLACIER PARK COMPANY



                                     By: /s/ Mark E. Ellis
                                         ---------------------------------------

                                     Its:  Vice President
                                           -------------------------------------



                                     BUYER:

                                     VINTAGE PETROLEUM, INC.



                                     By: /s/ Robert W. Cox
                                         ---------------------------------------

                                     Its:   Vice President
                                            ------------------------------------

                                                     Purchase and Sale Agreement
                                                                         Page 23

 
                              SCHEDULE OF EXHIBITS
                              --------------------

     The following exhibits have been omitted, and the Registrant agrees to
furnish supplementally a copy of any such omitted exhibits to the Securities and
Exchange Commission upon its request:

     A-1....................... Leases
     
     A-2....................... Equipment Leases/Rental Contracts

     A-3....................... Vehicles/Trailers

     A-4....................... Gathering Systems

     A-5....................... Excluded Interests

     B......................... Allocation Schedule

     C-1....................... Assignment and Bill of Sale

     C-2....................... Bill of Sale (Gathering System)

     C-3....................... Non-Participating Term Royalty Conveyance

     C-4....................... Assignment of ROWs and Easements

     C-5....................... Assignment of Equipment Leases

     C-6....................... Assignment of Contracts and Agreements

     C-7....................... Assignment of Gas Purchase Contracts

     C-8....................... Deed

     D......................... Preliminary Closing Statement

     E......................... Litigation

     F......................... Assumed Agreements

     G......................... Gas Imbalances

     H......................... Affidavit of Non-Foreign Status

     I......................... Data License Agreement

     J......................... Personnel

 
                                 AMENDMENT TO

                          PURCHASE AND SALE AGREEMENT


THIS AMENDMENT TO PURCHASE AND SALE AGREEMENT ("Amendment") dated March 11,
1997, is by and between BURLINGTON RESOURCES OIL & GAS COMPANY and GLACIER PARK
COMPANY ("Sellers"), both Delaware  corporations,  with offices at 5051
Westheimer, Suite 1400, Houston, Texas 77056-2124, BURLINGTON RESOURCES OFFSHORE
INC. ("BROI"), a Delaware corporation, with offices at 400 N. Sam Houston
Parkway E., Suite 1200, Houston, Texas 77060, and VINTAGE PETROLEUM, INC.
("Buyer"), a Delaware corporation,  with offices  at 4200 One Williams Center,
Tulsa, Oklahoma 74172.

WHEREAS, Sellers and Buyer are parties to a certain Purchase and  Sale Agreement
dated February 12, 1997 (the "Agreement");

WHEREAS, Sellers and Buyer have determined that BROI, an affiliated  company  of
Sellers, is the owner of certain assets ("Interests") more particularly
described in the Agreement;

WHEREAS, Sellers, Buyer  and BROI desire to include BROI as one of the "Sellers"
under the Agreement.

 
NOW, THEREFORE, in consideration of One Hundred Dollars ($100.00) and other good
and valuable consideration, the receipt and  sufficiency of which  are hereby
acknowledged, the parties hereby amend the Agreement as follows:

     1.     BROI is hereby made a party to the Agreement and included  as one of
            the "Sellers" thereunder, exactly as if BROI had been an original
            signatory party to the Agreement.  BROI shall be entitled to all
            rights and  subject to all obligations of Sellers under the
            Agreement.

     2.     Except as amended herein, all other terms and conditions of the
            Agreement shall remain unaltered and in full force and effect.

     3.     This Amendment shall be binding upon the parties hereto, their
            successors and assigns.

                                       2

 
IN WITNESS WHEREOF, the parties have executed this Amendment as of the date
first above mentioned.

                                       SELLERS:
                                       --------

                                       BURLINGTON RESOURCES OIL & GAS COMPANY


                                       By:   /s/ Mark E. Ellis
                                          -------------------------------------
                                             Mark E. Ellis, Vice President


                                       GLACIER PARK COMPANY


                                       By:   /s/ Mark E. Ellis
                                          -------------------------------------
                                             Mark E. Ellis, Vice President


                                       BURLINGTON RESOURCES OFFSHORE INC.


                                       By:   /s/ Mark E. Ellis
                                          -------------------------------------
                                             Mark E. Ellis, Vice President


                                       BUYER:
                                       ------

                                       VINTAGE PETROLEUM, INC.


                                       By:   /s/ Robert W. Cox
                                          -------------------------------------
                                             Robert W. Cox, Vice President

                                       3

 
[LETTERHEAD OF BURLINGTON RESOURCES APPEARS HERE]

                                March 20, 1997



Vintage Petroleum, Inc.
4200 One Williams Center
Tulsa, Oklahoma 74172

Attn:  Robert W. Cox

     Re:  PURCHASE AND SALE AGREEMENT DATED FEBRUARY 12, 1997

Gentlemen:

     This letter shall set forth the agreement of Burlington Resources Oil & Gas
Company, Glacier Park Company and Vintage Petroleum, Inc. to amend Section 19 of
the referenced Purchase and Sale Agreement among the parties to substitute the
date of March 26, 1997 in the first sentence of such Section in place of the
date of March 21, 1997 as currently provided therein.

     If the foregoing correctly sets forth our agreement, please execute in the
space provided below.

                                Yours very truly,

                                BURLINGTON RESOURCES OIL & GAS COMPANY


                                By:    /s/ Illegible
                                   -----------------------------------------


                                GLACIER PARK COMPANY


                                By:    /s/ Illegible
                                   -----------------------------------------

AGREED TO AND ACCEPTED
THIS 20TH DAY OF MARCH, 1997

VINTAGE PETROLEUM, INC.


By:  /s/ Robert W. Cox
   --------------------------