Abstract: A Geochemical Study of Potential Source Rocks and Crude Oils in the Anadarko Basin, Oklahoma

Huai Da Wang, Richard Paul Philp

Source rocks and crude oils from several non-Woodford Paleozoic formations in the Anadarko Basin, Oklahoma have been characterized by organic geochemical techniques. Since the Woodford Shale is an important source rock in the basin and has been investigated intensively in previous studies, the Woodford shale and associated oils was also characterized and used as a reference formation to compare with other formations and oils examined in this study.

Based on the results of screening analyses and geological information, a new source rock evaluation model (in forms of PGI maps) has been built to evaluate five formations. Besides the Woodford (which is proved by the model to be a very good source rock) the model indicates that the Viola Limestone is a good source rocks, especially in the eastern Anadarko basin. The Sylvan shale is not a very good source rock in the basin. The black shales in the Springer and Morrow are fairly good source rocks, especially for generation of natural gas. These results support the proposal of multi-source oil and gas generation in the Anadarko basin.

Source rock and crude oil samples were characterized using more organic geochemical techniques, which included ^dgr¹³>C, GC, GC/MS, GC/MS/MS, and pyrolysis GC/MS. The variations of biomarker distribution, concentration, and quantitation with maturity, migration, and weathering were investigated. The biomarker characteristics were combined with other geochemical and geological information to interpret the sources, depositional environments, diagenesis, migration, and weathering of the source rocks and associated oils. Apparent oil-source rock correlations were found between the source rocks studied and a number of crude oils using biomarker characterization.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994