August 18, 2004




TO:         All Limited Partners in the Geodyne Energy Income
            Limited Partnership III-D

RE:         Election to extend term of Partnership



      As previously  described to you, the limited  partnership  agreement  (the
"Agreement")  for the Geodyne  Energy  Income  III-D  Limited  Partnership  (the
"Partnership")  provides that the Partnership will  automatically  terminate and
dissolve on September 5, 2004.

      The Agreement gives Geodyne Resources, Inc., as General Partner, an option
to extend the term of the  Partnership for up to five additional two year terms.
Four years ago Geodyne  exercised  the first such  extension,  and two years ago
exercised the second such extension.

      The General Partner is hereby  notifying you that it has decided to extend
the term of the  Partnership  until  December  31,  2005.  Accordingly,  the new
termination date for the Partnership will be December 31, 2005.

      If you have any questions concerning the Partnership's  extension,  please
contact Geodyne Investor Services at 918-583-1791 or 888-436-3963.

                                    Very truly yours,

                                    GEODYNE RESOURCES, INC.
                                    General Partner



                                    Dennis R. Neill
                                    President