Petroleum Geology of Ouachita Uplift Region of Oklahoma

Jock A. Campbell, Neil H. Suneson

Oil has been produced in the Ouachita uplift for more than 70 years, having first been discovered at Redden field in 1914. However, as recently as 1971, workers considered the region a poor prospect because of complex structure and the effects of low-grade metamorphism on source and reservoir rocks, despite the presence of surface and shallow hydrocarbons. Consequently, systematic exploration and deep drilling in the region have occurred rarely. Curiale demonstrated that most of the Oklahoma Ouachita rocks are not overmature. Six Middle Ordovician through Mississippian black shale units contain adequate organic carbon to generate petroleum and are within the lower part of the oil window.

Two major petroleum plays are found in the Ouachita uplift region. Folded and thrusted strata constitute the shallower, and possibly the more extensive, of the two. Developed reservoirs include Bigfork Chert (Ordovician), Arkansas Novaculite (Devonian-Mississippian), sandstones within Stanley (Mississippian) and Jackfork (Morrowan) Groups, and Wapanucka Limestone-Spiro Sandstone (Morrowan-Atokan). The deeper play is characterized by underlying basement fault blocks. Development in the Arkoma basin indicates that major reservoirs will include Arbuckle group carbonates. This play is limited to the south by increasing depth and by seismic resolution of the fault blocks. Other potential reservoirs in both plays include Crystal Mountain and Blakely Sandstones (Ordovician), and Blaylock San stone (Silurian), with progressively older strata involved in thrusting southward across the uplift. The eastward extent of the "Arbuckle facies" of lower Paleozoic strata remains a major question.

AAPG Search and Discovery Article #91025©1989 AAPG Midcontinent, Sept. 24-26, 1989, Oklahoma City, Oklahoma.