November 1, 2005




TO:         All Limited Partners in the Geodyne Energy Income
            Limited Partnership II-A

RE:         Election to extend term of Partnership



      As previously  described to you, the limited  partnership  agreement  (the
"Agreement")  for the  Geodyne  Energy  Income  Limited  Partnership  II-A  (the
"Partnership")  provides that the Partnership will  automatically  terminate and
dissolve on December 31, 2005.

      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.
To date, the General Partner has exercised two of those options.

      The General Partner is hereby  notifying you that it has decided to extend
the term of the  Partnership  for a third two-year term until December 31, 2007.
Accordingly,  the new termination  date for the Partnership will be December 31,
2007.

      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

                                    //s// Dennis R. Neill

                                    Dennis R. Neill
                                    President