Abstract

The Gulf of Mexico Basin is one of the richest hydrocarbon basins of the world, with estimated ultimate recoverable hydrocarbon reserves exceeding 140 billion barrels of oil equivalent. However, opportunity space in the primary Paleogene subsalt play of the ultra-deepwater is beginning to narrow and operators are looking more closely at the Mesozoic in offshore areas, particularly in the eastern Gulf of Mexico. This is timely as emerging new ideas are leading to a reevaluation of the Mesozoic framework history, including how the Chicxulub impact event at the end of the Cretaceous altered the deep Gulf of Mexico seascape and set up subsequent deepwater deposition. New models have been formulated for the timing and distribution of salt deposition and sea-floor spreading. Our understanding of the Mesozoic source to sink system transport system and basin entry points continues to evolve. Onshore Gulf of Mexico drilling and new biostratigraphic data from deep-water wells has reinvigorated Mesozoic biostratigraphy work. Wells drilled in the deep subsalt province have altered our view of the Mesozoic source to sink depositional pathways (Figs. 1 and 2), leading us to question previous North American paleogeographic maps. Onshore, exploitation of source rocks as shale gas plays in the Jurassic Haynesville, and Cretaceous Eagle Ford and Tuscaloosa Marine Shale (Fig. 3) have generated significant drilling activity and this in turn has stimulated a reexamination of interpreted Mesozoic source rock distributions, including offshore areas of the Gulf of Mexico. Our perspective on the Mesozoic exploration potential is likely to change as well, given new and ongoing seismic refraction and reflection work.