ABSTRACT

In the area of investigation, T20-23N, R7-10E, the Arbuckle Group consists almost entirely of dolomite and limestone; minor amounts of shale, sandstone and chert are included. The mounting of bit cuttings in the center of electric logs and correlation of the logs allows division of the Arbuckle Group into ad hoc units.

Locally, exploration for Arbuckle hydrocarbon production has centered around positive structural features with 20 feet or more of closure at the Pink Limestone level. Structural contour maps of the Pink Limestone marker bed and the top of the Arbuckle Group were compared and analyzed statistically to determine if a useful relationship exists with regard to structural closure, areal extent, dip and displacement of the axes of folds. Results indicate that structure at the top of the Arbuckle Group can be predicted by the Pink Limestone marker bed.

Positive structural features that existed prior to deposition of Mississippian sediments may be delineated by use of isopachous maps from the top of the Pink Limestone marker bed and base of the Mississippian to the top of the Arbuckle Group. These maps should be used in conjunction with structural contour maps of the Pink and Arbuckle. Thinning of the Arbuckle to Mississippian interval apparently is due to positive anticlinal and domal folds having existed before Mississippian time.

Four basic types of hydrocarbon traps in the Arbuckle Group are due to (1) folding, (2) faulting, (3) facies changes, and (4) combinations of folding and stratigraphic changes. Production strictly related to facies changes has not been demonstrated in the study area.