MANCINI, ERNEST A., and D. JOE BENSON, Center for Sedimentary Basin Studies and Department of Geology, University of Alabama,Tuscaloosa,AL

Abstract: Integration of 3-D Seismic Reflection Data with 3-D Geologic Visualization Modeling for Petroleum Reservoir and Trap Delineation, Eastern Gulf Coastal Plain, USA

In the eastern Gulf Coastal Plain of the United States, Upper Jurassic petroleum traps are related to salt movement or basement features. The carbonate petroleum reservoirs associated with these traps are reef and shoal lithofacies. Although potential petroleum traps can be defined using 3-D seismic reflection technology, the delineation of the associated carbonate reservoir-grade rock requires an integration of 3-D seismic imaging and 3-D geologic visualization modeling. Case studies of North Choctaw Ridge Field and Appleton Field, southwestern Alabama demonstrate the importance of using an integrated geoscientific approach. The petroleum trap at North Choctaw Ridge Field is the result of salt uplift which is related to salt movement associated with the extensional Gilbertown fault system. The petroleum reservoirs are Upper Jurassic Smackover grainstones and dolograinstones. The trap for this field is primarily structural in nature. The petroleum trapping mechanism in Appleton Field is a combination of structure and carbonate stratigraphy.The structural component is an anticline associated with a Paleozoic basement ridge. The stratigraphic component involves localization of favorable Smackover reef boundstones and doloboundstones and shoal grainstones and dolo-grainstones around and over the basement ridge. Distribution of reservoir grade rock, which is a result of depositional and diagenetic processes, is a critical part of the petroleum trap. These fields represent 2 of over 90 Smackover fields in the eastern Gulf Coastal Plain. Further study of these existing fields using integrated 3-D seismic imaging and 3-D geologic visualization modeling should result in the drilling of successful development wells in these fields and in the discovery of additional Smackover fields in the region.

AAPG Search and Discovery Article #90923@1999 International Conference and Exhibition, Birmingham, England