Gulf Coast Section

The northern deep-water Gulf of Mexico is one of the most active deep-water petroleum provinces in the world. This paper introduces the regional geologic setting for the northern deep-water Gulf of Mexico and briefly discusses the importance of technology in developing the area’s resources.

The 86 fields and discoveries in the central Mississippi Canyon, Atwater Valley, western DeSoto Canyon, and Lloyd Ridge protraction areas are summarized with production characteristics and representative seismic profiles and wire-line logs. Three trap styles are recognized: four-way closure, three-way closure, and stratigraphic.

The structural history of the Mississippi Canyon, Atwater Valley, western DeSoto, and western Lloyd Ridge protraction areas in the northeastern deep-water Gulf of Mexico is of a basin influenced by complex salt tectonics that controlled the formation of intraslope minibasins and sediment distribution.

The structural framework and evolution from the Middle Jurassic to the present of the Mississippi Canyon, Atwater Valley, western DeSoto Canyon, and western Lloyd Ridge protraction areas consist of a complex history influenced by basement fabric, multiple stages of salt movement, and gravitational gliding.

The petroleum geology of the Mississippi Canyon, Atwater Valley, western DeSoto Canyon, and western Lloyd Ridge protraction areas, offshore northern Gulf of Mexico, is controlled by the interaction of salt tectonics and high sedimentation rate during the Neogene and resulted in a complex distribution of reservoirs and traps.

Thunder Horse and Mensa are two of the largest fields of oil or gas, respectively, in the northern deep-water Gulf of Mexico. The fields are present in adjacent intraslope minibasins, located approximately 12 mi (19 km) apart in Mississippi Canyon. Both fields illustrate important complexities of deep-water sedimentation.

The Mensa and Thunder Horse intraslope minibasins in south-central Mississippi Canyon, northern deep-water Gulf of Mexico, had a linked structural evolution from the Early Cretaceous through the late Miocene. Analysis of the two minibasins illustrates the complexities of deep-water sedimentation and salt tectonics in intraslope minibasins.

The petroleum systems of two adjacent Miocene intraslope minibasins in the northern deep-water Gulf of Mexico are modeled to investigate why one of them produces primarily gas but the other produces oil. Specifically, the Mensa field produces gas from a faulted four-way closure that overlies a turtle structure, whereas the adjacent Thunder Horse field produces from a turtle structure with four-way structural closure.