Abstract

Correlation problems have long existed between the Pennsylvanian marine clastics of the northeastern half of the Anadarko Basin and Shelf and the Pennsylvanian terrigenous washes of the extreme southwestern portion of the Anadarko Basin. These correlation problems have created nomenclature problems resulting in thousands of feet of washes often referred to on completion reports and production records as "granite wash" or "Atoka Wash" when much greater accuracy and specificity is both needed and possible.

Since few detailed cross sections are available, regional and field scale cross sections were constructed which have been correlated well by well and field by field using nearly every deep well drilled in the basin. These cross sections have been correlated from the Heebner Shale down to the deepest zones penetrated. This process has provided for a high degree of consistency. These cross sections have greatly diminished the correlation and nomenclature problems within the Anadarko Basin.

Certain markers proved to be regionally persistent from the marine clastics into the terrigenous washes making the subdivision of thousands of feet of washes possible. Those of greatest importance were the top of the Marmaton, the Cherokee Marker, the Pink "Limestone" interval, the top of the Atoka and the top of the Morrow. Once these and other subdivisions were made, production was allocated on a much more definitive basis. Additionally, detailed reservoir characterization of the reservoirs was conducted to include geologic and engineering data. Finally, a "field-specific" reservoir type log was identified.