Oil and Gas Potential of the Maritime Boundary Region in the Central Gulf of Mexico

Abstract

The U.S. Geological Survey conducted a detailed study in the first half of 1981 of the oil and gas resource potential in the Maritime Boundary region of the central Gulf of Mexico. The Maritime Boundary region encompasses a part of the Gulf where jurisdiction over natural resources by adjacent coastal countries has not yet been established. The region of investigation is divided into six assessment areas on the basis of their generally distinct geologic characteristics. Individual assessment areas comprise a total area of approximately 58,940 mi2 (152,660 km2) and contain a total estimated sediment volume of 188,140 mi3 (784,170 km3). Water depths within the overall study region range from a minimum of 98 ft (30 m) on the contin ntal shelf off the Rio Grande to a maximum of about 12,270 ft (3,740 m) in the deep abyssal plain of the west-central Gulf; more than 75% of the study region is in water depth exceeding 10,000 ft (3,048 m). The study focused on factors critical to the generation, migration, and entrapment of hydrocarbons, such as: source beds and thermal maturation, reservoir rocks, structural and stratigraphic traps, and seals and timing of hydrocarbon migration relative to formation of traps. The oil and gas potential was analyzed using all publicly available geophysical data recorded in the region supplemented by a limited amount of geologic information synthesized from reports on drill holes and bottom cores within and adjacent to the region of study. A variety of evidence suggests that favorable conditions exist for the occurrence of crude oil and natural gas resources in the Maritime Boundary region. Estimates of the in-place resources (recovery factors were not applied) of crude oil and natural gas range from 2.24 to 21.99 billion bbl and from 5.48 to 44.4 tcf, respectively. The individual assessment areas appear to have the most attractive petroleum potential in the following order: Perdido Foldbelt, Sigsbee Knolls, Abyssal Gulf Basin, Campeche Escarpment, Rio Grande Margin, and Sigsbee Escarpment. Estimates of the amount of petroleum resources that might be ultimately recoverable were not calculated because not enough is known at present about reservoir properties, economics, and the technology needed to develop the deep-water areas. However, exploitation of these deep-water areas. However, exploitation of these deep-water resources is expected to be technically feasible within the next 20 to 30 years.