Salt Geology and Hydrocarbon Plays in the Northeastern Gulf of Mexico
In the Northeastern Gulf of Mexico offshore, two pre-stack depth migration projects were undertaken recently to better image the salt geology and new plays. The Phase 46 survey area covers the eastern Mississippi canyon, Main Pass and Viosca Knoll, and the western Destin dome, Desoto Canyon and northern Lloyd Ridge. P-49 survey is an infill of P-46 in the Desoto Canyon and Lloyd Ridge. The surveys together comprise approximately 24,000 line miles of 2D seismic data. The surveys were pre-stack depth migrated and is currently being used for a deep-water interpretation project integrating approximately 1100 wells, including 300 biostratigrahic wells. The pre-stack depth migrated data identify major geologic sequence boundaries, associated depositional units, salt features and various hydrocarbon plays. The autochthonous Mid- Jurassic Louann (mother) salt, Upper Jurassic sediments and the overlying Tertiary sequences are well manifested in the data sets. In the Mississippi Canyon area to the west, the expanded Miocene play is characterized by broad rollover structures created by the loading of sediments, deflation and subsequent withdrawal of the mother salt. The Tertiary sections thin to the east as the basement ramps up towards the Florida Platform, at the expense of Cretaceous and Jurassic Rocks that constitute the potential plays associated with salt rollers and diapirs. The good imaging of the sedimentary section and folded structure helps delineate the Tertiary and Mesozoic plays in the survey area.
The pre- stack depth migrated data offers opportunities for conducting detailed exploration including finding new plays below the proven Miocene section in the Mississippi Canyon area. New Wilcox play, the Wilcox Paleocene-Eocene Play west of Mississippi canyon is yet to be tested in the Mississippi canyon. To the east, the Mesozoic Jurassic- Cretaceous plays have been tested by some wells. Further east, the shelf edge and carbonate Platform areas offer opportunities for these plays as well as the carbonate and reef plays as an extension of the onshore plays e.g. Jurassic/ Cretaceous Norphlet, Smackover and Cotton Valley plays.
AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009