Salt Geology and New Plays in Dee p-Water Gulf of Mexico*
In deep-water Gulf of Mexico, two pre-stack depth migration projects were undertaken recently to better image the deep-water salt and sub-salt geology. The Phase 45 Too (P-45) survey area, stretching from Corpus Christi/Port Isabel in the west to Atwater Valley in the east, comprises approximately 100,000 line kilometers of 2D seismic data. It was pre-stack depth migrated and is currently being used for a deep-water interpretation project integrating approximately 1100 wells, including 300 biostratigrahic wells. In the Mississippi Canyon area, approximately 900 OCS blocks (4.8 km x 4.8 km each) of 3D seismic data were pre-stack depth migrated. More than 80 salt penetration wells were integrated in the Mississippi Canyon salt model interpretation project. The pre-stack depth migrated data identify autochthonous and allochthonous salt and associated archetypes. The autochthonous Jurassic Louann (mother) Salt, Jurassic sediments, and the overlying Cretaceous and Paleogene sequences are well manifested in the data sets. The new Lower Tertiary play is typically characterized by broad rollover structures created by the loading of sediments, deflation and withdrawal of the mother salt, and subsequent collapse of the sediments. The good imaging of the sedimentary section and folded structure below the salt helps delineate the new Lower Tertiary play, which has proven successful in many parts of the P-45 area, and can possibly be tested in Mississippi Canyon. Introduction Salt and sediment interactions play a major role in producing reservoir rocks and traps for hydrocarbon accumulation in the Gulf of Mexico (GOM). Advanced seismic technology, specifically pre-stack depth migration, and deep-water wells drilled recently have provided better understanding of salt geology and new plays for hydrocarbon accumulations. This deepwater regional study extends from the Corpus Christi/Port Isabel protraction areas in the west, eastward to the Mississippi Canyon protraction area, northward to the shelf/slope break and southward to the US-Mexico border. Data Two seismic pre-stack depth migrated data sets (Figure 1) were used to better understand the deep-water salt and associated geology. Phase 45 Too (P-45), a regional 2D project, integrated approximately 1100 wells, including 300 biostratigraphic wells, in the interpretation of salt and regional geology. Mississippi Canyon, a large 3D project, utilized a significant number of wells to enhance the velocity model for migration. The data sets are described below: