Abstract

The recent past of the Gulf of Mexico OCS Shelf provides the best indicator of its future. This paper examines that past in detail to provide strategic directions for the future exploration and development of the federal shelf.

From 1991 to 1998, reserve additions on the federal shelf totaled an impressive 6.66 billion barrels oil equivalent, nearly 70% of which was natural gas. These additions came predominantly from reserve growth (essentially extensions and new pool discoveries) in older fields, not from new field discoveries. Recent (1989-1998) discoveries accounted for less than 16% of total reserve additions on the shelf. Reserve growth from older fields was so predominant that average absolute growth in older fields was more than 25% larger than the average size of recent discoveries. Moreover, reserve growth by field was often substantial. Nearly 10% of the older fields on the shelf (65 of 681) had recent reserve additions greater than 25 million barrels oil equivalent.

Further insight into future possibilities is provided by an examination of recent shelf reserve additions by broad groups of lease areas, by geologic age, and by play type (combinations of reservoirs by chronostratigraphic age and depositional style). This analysis highlights the most likely possibilities for successful future exploration and development.