Abstract: Favorable Hydrocarbon Potential Predicted for Ouachita Mountains

Robert C. Morris

The Ouachita Mountains of Oklahoma have considerable potential for hydrocarbons, particularly dry gas. The exploration key will be the utilization of a deep-sea fan model for E-log and outcrop data of Stanley-Jackfork clastic rocks. Dark shales from many zones have been brought to stages of diagenesis adequate to generate oil and gas. Sandstones have undergone reduction in porosity and permeability by pressure solution as well as development of quartz overgrowths yet many still have adequate textures when compared with producing zones in the Arkoma basin. The more favorable sandstones were sandy debris flows within distributary channels and proximal turbidites forming suprafan depositional lobes of deep-marine fans. Blanket distal turbidites of the active outer fan are un avorable. Thick, favorable sandstones are present at many stratigraphic horizons in both the Stanley and Jackfork but shift laterally as well as up or down the fan axis. Anticlinal axes are crushed, shattered, and faulted with substantial decrease in favorable sandstone textures whereas broad synclines are altered least by tectonism. Ideal exploration "fairways" will combine effective sand development, minimal sandstone diagenesis, and best structural position, probably intermediate between anticlinal and synclinal axes. Surface mapping and photogeology will be a more effective tool than seismic reflection surveys because of lack of reflections under surface anticlines. Search for gas in fractured cherts of older zones will require a thorough understanding of the development of multiple, transcurrent thrust faults and folds from compressional overburden tectonics.

AAPG Search and Discovery Article #90968©1977 AAPG-SEPM Annual Convention and Exhibition, Washington, DC