Regional Seismic Interpretations and Structural Modeling of the Onshore Northwestern Gulf of Mexico Basin

Abstract

In preparation for upcoming assessments of the undiscovered, technically recoverable oil and gas resources in several formations of the onshore coastal plain and State waters of the U.S. Gulf Coast, the U.S. Geological Survey (USGS) is continuing research on the generation, migration, and accumulation of hydrocarbons across the Gulf of Mexico Basin. This effort includes an examination of the impact of the basin's structural evolution on the Upper Jurassic-Cretaceous-Tertiary Composite Total Petroleum System. The USGS has licensed and interpreted a series of regional-scale dip-oriented 2D seismic lines that cover Texas, Louisiana, and western Mississippi. The lengths of each line range from approximately 160 km to 450 km. Each seismic line begins near the coastline and extends updip across the Lower Cretaceous shelf edge. Interpretations are shown for twelve of these regional seismic lines. Analyzing this sequence of interpreted seismic lines provides a clear perspective on how key structural elements of the northwestern Gulf of Mexico Basin (including fault zones, uplifts, interior salt basins, and coastal diapir provinces) vary along strike. Based upon interpretations of these lines, structural restorations have been constructed that model the post-Middle Triassic sequential structural evolution for this part of the Gulf of Mexico Basin. Additionally, a suite of geohistory curves have been constructed for wells along each of the seismic lines in order to model the timing of hydrocarbon generation from the Oxfordian Smackover Formation and the Cenomanian-Turonian Eagle Ford Shale. Combining the seismic interpretations and structural models with the geohistory curves highlight the differences in timing of hydrocarbon generation between different Gulf Coast structural provinces.

AAPG Datapages/Search and Discovery Article #90216 ©2015 AAPG Annual Convention and Exhibition, Denver, CO., May 31 - June 3, 2015