ABSTRACT

The Southeast Thomas Oil and Gas Field is located in Custer County, west-central Oklahoma. This field produces from the Desmoinesian Red Fork Sandstone at depths between 10,000 and 11,000 feet.

The Red Fork Sandstone is part of the Middle Pennsylvanian (Desmoinesian) "Cherokee" Group. This group consists of limestones and sandstones deposited by transgressive-regressive cycles of the Cherokee Sea. Four lenticular sand bodies, the Prue, Upper Skinner, Lower Skinner, and Red Fork, mark periods of maximum regressions of the Cherokee Sea. These sands were deposited by a fluvially-dominated deltaic system. The Red Fork Sandstone shows a typical multi-lateral distributary channel pattern. The non-channel deposits include distributary mouth bars and delta front sands and muds.

Delineation of the Red Fork distributary channel system provides information valuable in development of exploration trends in the Southeast Thomas Field.