Fifth Amendment to
             Agreement and Certificate of Limited Partnership of
               Geodyne Energy Income Limited Partnership III-G


     This Fifth Amendment to Agreement and Certificate of Limited Partnership of
Geodyne Energy Income Limited  Partnership III-G (the  "Partnership") is entered
into  by  and  between  Geodyne  Resources,   Inc.  ("Resources"),   a  Delaware
corporation,   as  successor  General  Partner,   Geodyne   Depositary   Company
("Depositary"),  a  Delaware  corporation,  as  the  Limited  Partner,  and  all
Substituted Limited Partners admitted to the Partnership.

     WHEREAS, on September 20, 1991, Geodyne Production Company  ("Production"),
as General  Partner,  and  Depositary  executed  and entered  into that  certain
Agreement  and  Certificate  of  Limited  Partnership  of the  Partnership  (the
"Agreement"); and

     WHEREAS,  on February 25, 1993,  Production  executed and entered into that
First  Amendment  to the  Agreement  whereby  it  changed  (i)  the  name of the
Partnership from  "PaineWebber/Geodyne  Energy Income Limited Partnership III-G"
to "Geodyne Energy Income Limited  Partnership  III-G",  (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,  on August 4, 1993,  Production  executed  and  entered  into that
Second Amendment to the Agreement  whereby it amended certain  provisions to (i)
expedite  the  method  of  accepting  transfers  of Unit  Holders'  Units in the
Partnership  and (ii)  provide  for an optional  right of  repurchase/redemption
which may be exercised by the Unit Holders; and

     WHEREAS,  on August 31,  1995,  Production  executed  and entered into that
Third Amendment to the Agreement whereby it amended certain  provisions to allow
transfers  of Units  facilitated  through a matching  service to the extent that
such  transfers   otherwise   comply  with  Internal  Revenue  Service  transfer
regulations  applicable  to  non-permitted  transfers  for  non-publicly  traded
limited partnerships; and

      WHEREAS,  on  July  1,  1996,  Resources,   as  successor  via  merger  to
Production,  executed and entered into, as General Partner,  that certain Fourth
Amendment  to the  Agreement  of Limited  Partnership  whereby  it  amended  the
Agreement to provide that Resources,  as successor via merger to Geodyne, is the
General Partner of the Partnership; and

      WHEREAS,  Section 2.3 of the Agreement provides that the Partnership shall
continue  in full  force and effect for a period of ten (10) years from the date
of its  Activation  (as  defined in the  Agreement),  provided  that the General
Partner  may extend the term of the  Partnership  for up to five  periods of two
years each if it believes  each such  extension is in the best  interests of the
Unit Holders or until  dissolution  prior thereto  pursuant to the provisions of
the Agreement, and

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      WHEREAS,  Resources  as General  Partner has elected to extend the life of
the Partnership an additional two years.

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

      Section 2.3. is hereby amended and restated as follows:

                  The  Partnership  shall  continue  in force and  effect  until
            September 20, 2003, provided that the General Partner may extend the
            term of the  Partnership for up to four periods of two years each if
            it believes  such  extension  is in the best  interests  of the Unit
            Holders,   or  until  dissolution  prior  thereto  pursuant  to  the
            provisions hereof.

      IN WITNESS WHEREOF, the parties hereto have hereunto set their hands as of
this 6th day of September, 2001.

                                    GEODYNE RESOURCES, INC.,
                                    as General Partner

                                    By:   /s/ Dennis R. Neill
                                          ---------------------
                                          Dennis R. Neill
                                          President

                                    GEODYNE DEPOSITARY COMPANY,
                                    as the Limited Partner

                                    By:   /s/ Dennis R. Neill
                                          ---------------------
                                          Dennis R. Neill
                                          President

                                    GEODYNE RESOURCES, INC.
                                    as Attorney-in-Fact for all
                                    Substituted Limited Partners

                                    By:   Dennis R. Neill
                                          ---------------------
                                          Dennis R. Neill
                                          President


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