The stratigraphic and tectonic framework of the DeSoto Canyon and Lloyd Ridge protraction areas, northeastern Gulf of Mexico: implications for the petroleum system and potential play types

Pyles, D. R., Paul Weimer, Department of Geological Sciences, University of Colorado, Boulder, CO, and Renaud Bouroullec

Abstract

The ultra-deep northeastern Gulf of Mexico reflects one of the last frontier exploration areas in the U.S. Gulf. The area is tentatively scheduled to be leased in December, 2001. Analysis of 10,000 km of 2-D seismic data allows us to evaluate the six components of petroleum systems of the area. Potential reservoirs range in age from Upper Jurassic to Quaternary. Jurassic and Cretaceous strata are interpreted to be primarily fine-grained, deep water carbonate in origin. The Paleogene section is thin and condensed. Beginning during the middle Miocene, significant deep water sediment was delivered to the area from the north (Mississippi Canyon area). These sediments reflect deposition in largely unconfined turbidite systems, so the need for large stratigraphic or combined traps is important for the development of this area.

Structural traps in the lease area consist of areally large, low relief closures associated with deformation of the Louann Salt during the Cretaceous. Some of these structures include the Neogene sediments. Little to no allochthonous salt exists in the area. Adequate seals are interpreted to be present throughout the stratigraphic section because of the largely mud-dominated nature of the stratigraphic section.

Source rocks are interpreted to be present in the area. Carbonate-rich source rocks (Upper Jurassic) producing high sulfur oils are probably present. Oil seeps from the Mississippi Fan Foldbelt also indicate the presence of a mature Jurassic siliciclastic source interval. Petroleum systems modeling indicate that the deeper portions of the area are mature. The greatest risk is the presence of adequate traps and reservoirs to capture the large volumes of oil necessary for the province to be economic.