Print this pageAtlas of Northern Gulf of Mexico Gas and Oil Reservoirs
SENI, S. J.,D. A. MARIN, J. R BROOKE, and ERIC KAZANIS
The U.S. Department of Energy, the Minerals Management Service, and the Gas Research Institute, through their support of The University of Texas at Austin Bureau of Economic Geology and in collaboration with other state geological surveys have analyzed geologic and engineering data on a play basis for all reservoirs in the Federal OCS and State offshore waters of Texas, Louisiana, and Alabama of the northern Gulf of Mexico. Ninety-one chronostratigraphic plays have been identified in the northern Gulf of Mexico primarily on the basis of age, depositional style, and structure. For the first time, geologic and engineering attributes of more than 10,000 sandstone-body reservoirs in the northern Gulf of Mexico may be spatially analyzed using a geographic information system (GIS) that links tabular data to spatially referenced location data such as the outline of fields and plays.
Hydrocarbons in the northern Gulf of Mexico are unevenly distributed in terms of age, location, and depositional style. Recoverable in-place hydrocarbons in the Federal OCS are hosted primarily by Pleistocene plays (40%), Miocene plays (39%), Pliocene plays (20%), and Mesozoic plays (1%). In the Federal OCS, cumulative oil production is apportioned to three primary depositional styles- progradational (58%), aggradational (23%), and submarine fan (16%). However, oil reserves are apportioned to submarine fan (44%), progradational (43%), and aggradational (10%) depositional styles. This reflects the recent discovery of large oil reserves in deep water. On the continental shelf, progradational environments are hydrocarbon rich owing to favorable sandstone-to-shale ratios and association with salt structures and faulted anticlines. Submarine-fan reservoirs dominate downdip of the modern shelf edge. Reservoir depth, pay thickness, porosity, and water saturation show statistically significant variations in play-average values.