Second Amendment to Amended and Restated
               Agreement and Certificate of Limited Partnership of
                  Geodyne Energy Income Limited Partnership I-F


      This Second Amendment to Amended and Restated Agreement and Certificate of
Limited  Partnership  of Geodyne  Energy  Income  Limited  Partnership  I-F (the
"Partnership")  is  entered  into  by  and  between  Geodyne  Properties,   Inc.
("Properties"),  a Delaware corporation,  as General Partner, and all Additional
and Substituted Limited Partners admitted to the Partnership.

      WHEREAS, on September 10, 1986, Properties and the Initial Limited Partner
executed and entered into that certain PaineWebber/Geodyne Energy Income Limited
Partnership   I-F  Agreement  and  Certificate  of  Limited   Partnership   (the
"Preformation Agreement"); and

      WHEREAS,  on December 17, 1986,  Properties executed and entered into that
certain Amended and Restated  Agreement and  Certificate of Limited  Partnership
(the "Amended Agreement"); and

      WHEREAS,  on February 25, 1993,  Properties executed and entered into that
certain First Amendment to the Amended Agreement of Limited  Partnership whereby
it changed  (i) the name of the  Partnership  from  "PaineWebber/Geodyne  Energy
Income Partnership I-F" to "Geodyne Energy Income Limited Partnership I-F", (ii)
the address of the  Partnership's  principal  place of  business,  and (iii) the
address for the Partnership's agent for service of process; and

      WHEREAS,  Section 10.1 of the Amended Agreement  provides that the General
Partner may, without prior notice or consent of any Limited  Partner,  amend any
provision of this Amended  Agreement and  Certificate  if, in its opinion,  such
amendment does not have a material adverse effect upon the Limited Partners; and

      WHEREAS,  Properties  as  General  Partner  desires  to amend the  Amended
Agreement in order to (i) expedite the method of accepting  transfers of Limited
Partners' Interests in the Partnership and (ii) revise the terms of the optional
right of presentment which may be exercised by the Limited Partners.

      NOW,  THEREFORE,  in  consideration  of  the  covenants,   conditions  and
agreements herein contained, the parties hereto hereby agree as follows:

I.    The last  sentence  contained in Section 7.3A of the Amended  Agreement is
      hereby amended and restated as follows:




                                      -1-
<PAGE>





            Any sale,  assignment or transfer shall be recognized by the Limited
      Partnership as effective on the first business day of the month  following
      the General Partner's receipt of such notification.


II.   The Amended  Agreement is hereby  amended to provide for a new Article 15.
      Said Article is hereby stated as follows:


                                   Article 15

            Section 15.1.   Optional Repurchase Right
            --------------------------------------

            Any Limited Partner shall have the right, at his option,  to present
            his Interests to the General Partner or its designated Affiliate for
            repurchase on the basis set forth in this Article 15.

            Section 15.2.   Procedure for Repurchase
            -------------------------------------

            A.    As  of  December  31,  1992  and  annually   thereafter   (the
                  "Appraisal  Date") the  General  Partner  shall  appraise  the
                  Proved Reserves and other assets of the  Partnership  pursuant
                  to  the  provisions  set  forth  herein  and  shall  assign  a
                  repurchase  price  (the  "Repurchase  Price")  to the  Limited
                  Partners'  Interests in the Partnership in accordance with the
                  provisions set forth herein.

            B.    In arriving at the Repurchase Price, the General Partner shall
                  consider  those  factors  deemed  relevant  by  it  including,
                  without limitation, the following:

                  (i)   the present value of the  estimated  future net revenues
                        of  the  Production   Partnership's   Proved   Reserves,
                        calculated as described below; and

                  (ii)  the  book  value of all  other  Partnership  assets  and
                        liabilities.




                                      -2-
<PAGE>





            Section 15.3.   Calculation of Present Value of the
                            Partnership's Estimated Future Net Revenues
            -----------------------------------------------------------

            In  calculating  the present  value of the  Partnership's  Estimated
            Future Net  Revenues  the General  Partner  shall use the  petroleum
            engineering reports and other petroleum reserve information required
            to be furnished to the Limited Partners  pursuant to Section 9.4C of
            the Agreement.

            Future gross revenues expected to be derived from the production and
            sale  of  the  Proved   Reserves   attributable  to  the  Production
            Partnership's  Producing  Properties shall be estimated using either
            (i) escalations of future sales prices of  Hydrocarbons  supplied by
            the General Partner (the  "Escalated  Case") or (ii) sales prices of
            Hydrocarbons  provided by Regulation  S-X adopted by the  Securities
            and Exchange Commission (the "SEC Case"), as the General Partner may
            determine in its sole discretion.

            Future net revenues  shall be  calculated  by deducting  anticipated
            expenses  (using either (i)  escalations of future costs supplied by
            the General  Partner if the General  Partner  adopted the  Escalated
            Case with  respect to future sales  prices of  Hydrocarbons  or (ii)
            constant  future costs if the General  Partner  adopted the SEC Case
            with respect to future sales prices of Hydrocarbons)  from estimated
            future gross revenues.

            The present value of the future net revenues  shall be calculated by
            discounting the estimated  future net revenues at either 10% (if the
            General Partner  employed future pricing criteria in accordance with
            the SEC Case) or that rate per annum which is one  percentage  point
            higher than the prime rate of interest of The Chase  Manhattan Bank,
            N.A. or any successor bank, as of the Appraisal Date (if the General
            Partner  employed  pricing criteria in accordance with the Escalated
            Case, provided, however, that such discount rate will not exceed 18%
            per annum and will be no less than 10% per annum).



                                      -3-
<PAGE>




            Section 15.4.  Risk Reduction.
            -----------------------------

            In determining the Repurchase Price for Limited Partners pursuant to
            this  Section  15, the  present  value of the  Partnership's  Proved
            Developed  Producing  Reserves  shall be reduced by 25% for risk and
            the present value of all other  categories of Proved  Reserves shall
            be reduced by 35% for risk. The risk reductions  shall be subject to
            upward or downward  adjustment by the General Partner if, during the
            period between the Appraisal Date and the Effective Date (as defined
            in Section 15.5),  there has been a material increase or decrease in
            the current  price of oil or gas or in the  estimated  amount of the
            Partnership's Proved Reserves.

            Section 15.5.   Tender Procedure
            ------------------------------

            Upon completion of the appraisal of the  Partnership's  assets as of
            the Appraisal  Date,  the General  Partner shall notify each Limited
            Partner of the Repurchase Price and his proportionate  share thereof
            and either the General  Partner or one of its Affiliates  will offer
            to purchase  such Limited  Partner's  Interests in exchange for such
            Unit  Holder's  proportionate  share  of  the  Repurchase  Price  (a
            "Repurchase  Offer").  Any  Limited  Partner  desiring  to do so may
            accept such Repurchase Offer by notifying the General Partner of his
            election. Limited Partners so notifying the General Partner shall be
            referred  to herein as  "Electing  Limited  Partners".  The  General
            Partner or its designated  Affiliate shall thereupon promptly pay to
            each Electing  Limited  Partner,  his proper share of the Repurchase
            Price,  calculated as herein set forth, within 30 days from the date
            which a properly drawn assignment of such Electing Limited Partner's
            interest, free and clear of all liens and encumbrances,  is tendered
            to and accepted by the General  Partner or its designated  Affiliate
            (the "Effective Date").  Upon the acquisition of an Electing Limited
            Partner's Interests, the General Partner or its designated Affiliate
            shall, as of the Effective Date of such acquisition,  succeed to all
            the rights and obligations attributable to such interest.




                                      -4-
<PAGE>





            Section 15.6.  Monthly Adjustment to Repurchase Price
            ----------------------------------------------------

            The  Repurchase  Price  shall  be  recalculated   monthly  with  the
            Repurchase   Price   being   reduced  by  the  amount  of  any  cash
            distributions  to  Limited  Partners  during  the  period  from  the
            Appraisal  Date to the date of the payment of the  Repurchase  Price
            and shall  otherwise  be  adjusted to reflect the effect of material
            operations  during such  period,  including  a material  increase or
            decrease  in the  current  price  of oil or gas or in the  estimated
            amount  of the  Partnership's  Proved  Reserves.  In the  event  the
            Repurchase  Price is adjusted  for any reason  other than to reflect
            the payment of cash distributions, the General Partner shall provide
            written  notification of such adjustment to the Limited  Partners at
            least  ten (10)  business  days  prior to  acceptance  of Units  for
            purchase.

            Section 15.7.  Limitation on Units Repurchased
            ----------------------------------------------

            A.  At the sole  discretion  of the  General  Partner,  the  General
                Partner  or its  designated  Affiliate  may either (i) limit the
                time  period  in  which  it  will  accept   tendered  Units  for
                repurchase  or (ii) limit the amount of Units to be accepted for
                repurchase;  provided,  however,  that in any event  the  annual
                repurchase  offer will (i) remain open for at least  thirty (30)
                days and (ii) the General  Partner or its  designated  Affiliate
                will offer to annually  repurchase  (and will  purchase  validly
                presented  Units) at least 10% of the  outstanding  Units of the
                Partnership.  In the event the General Partner or its designated
                Affiliate imposes a limitation,  the General Partner will either
                (i) specify such  limitation(s)  in the annual  Repurchase Offer
                mailed to the  Limited  Partners  or (ii)  provide  all  Limited
                Partners  with written  notification  of such  limitation(s)  at
                least thirty (30) days prior to the  effective  date of any such
                limitation(s).

            B.  In the event the General  Partner  imposes a limitation upon the
                number of Interests to be  repurchased in the  Partnership,  and
                the amount of Interests tendered,  but not repurchased,  exceeds
                such  limitation,  such tendered  Interests will be accepted for
                repurchase by lot.




                                      -5-
<PAGE>





            C.  In  addition,  in order to avoid  certain  possible  adverse tax
                consequences,  the General  Partner may, in order to comply with
                the  regulations  or  procedures  under  Section  469(k)  of the
                Internal Revenue Code of 1986, as amended, relating to "publicly
                traded  partnerships,"  (i) delay or defer the Effective Date of
                any  repurchase  and (ii) limit the total number of Interests of
                any  Partnership to be repurchased in any 12-month period to the
                maximum number provided in such  regulations and procedures.  In
                the event of such delay or deferral,  the General  Partner shall
                notify the Electing  Limited Partner of the reasons therefor and
                shall  provide the Electing  Limited  Partner with the option to
                withdraw his tender of Interests for repurchase.

      IN WITNESS WHEREOF, the parties hereto have hereunto set their hands as of
the 4th day of August, 1993.

                                       Geodyne Properties, Inc.
                                       as General Partner


                                       By:  // C. Philip Tholen //
                                            ----------------------
                                            C. Philip Tholen
                                            President

                                       Geodyne Properties, Inc.,
                                       as Attorney-in-Fact for
                                       the Limited Partners

                                       By:  // Dennis R. Neill //
                                            ---------------------
                                            Dennis R. Neill
                                            Sr. Vice President