ABSTRACT: Geology of the Cottonwood Creek Field, Carter County, Oklahoma

Michael T. Roberts, David L. Read

In late 1987, the Cottonwood Creek field, Carter County, Oklahoma, was heralded by flows of nearly 4000 BOPD and 3 MMCFGD from the upper Arbuckle Group. The field structure is part of the buried Criner uplift along the southwest flank of the Ardmore basin. The uplift formed during a Late Mississippian/Early Pennsylvanian episode of bidirectional thrusting (northeast and southwest) probably related to convergent strike-slip

faulting. The basic field structure formed as a northeast-directed thrust plate, cored with Arbuckle Group carbonates and cut by a backthrust. The Cottonwood Creek anticline was near the crest of the uplift. It was erosionally denuded of its Simpson through Caney cover and karsted to depths of at least 1600 ft. Subthrust strata include the Woodford source rocks.

In the Middle to Late Pennsylvanian the uplift was buried by clastics (about 8000 ft thick over Cottonwood Creek). Culminating in the late Pennsylvanian, a second episode of wrench faulting sliced through the Criner uplift. About 3 mi of left-lateral slip occurred on this Criner-Healdton fault, which also dropped the anticline about 3000 ft relative to the block to the south, completing the trap at Cottonwood Creek field.

Fourteen wells have found oil in the anticline over an approximately 2.5 by 0.5-mi area. The oil column is at least 900 ft thick. Eight of the wells tested for 1200-3700 BOPD plus associated gas from a complex of fractures, Brown Zone dolomite, and karst-enhanced porosity in the West Spring Creek and Kindblade formations.

AAPG Search and Discovery Article #91003©1990 AAPG Annual Convention, San Francisco, California, June 3-6, 1990