Mesozoic ultra-deep water potential of the U.S. Gulf of Mexico – conceptual play development and analysis

Post, P. J., P. F. Harrison, G. L. Whittle, Minerals Management Service, New Orleans, LA; and J. D. Hunt, Bureau of Indian Affairs, Division of Energy and Mineral Resources, Lakewood, CO

Abstract

A series of conceptual Mesozoic plays was defined in the ultra-deep water U.S. Gulf of Mexico (GOM) by interpreting a 2x2 mile grid of 2-D seismic data covering an area of approximately 39,000 square miles basinward of the Sigsbee salt canopy. Time maps on the seafloor, approximate Cretaceous/Tertiary boundary, Mid-Cretaceous Sequence Boundary, approximate Jurassic/Cretaceous boundary, top autochthonous salt, and "basement" seismic events were constructed and converted to depth using regional interval velocities.

Conceptual plays in the western and central planning areas of the GOM include fold belts and buried hills; the latter have been subdivided into structural, stratigraphic-detrital, and drape plays.

In the eastern planning area, a structural play characterized by salt rollers, autochthonous salt swells, pinnacle salt structures/vertical salt welds, and salt growth and/or salt withdrawal (turtle) features was delineated in the West Florida Salt Basin.

Searching worldwide for fields having similar trap type, and reservoirs with comparable depositional environment identified reservoir analogs for each play. Monte Carlo simulations were run to analyze and develop distributions of the analog data. Petroleum system analysis was performed to incorporate, describe and display the elements (source, reservoir, and seal) and the processes (trap formation, generation–migration–accumulation, and critical moment) associated with each play. Play risks were evaluated, described, and presented using a "traffic light" ranking system.

The results of this study suggest that in the ultra-deep water GOM, these and other conceptual Mesozoic plays may offer a variety of future high-potential exploration opportunities.