NEHRING, RICHARD , NRG Associates, Colorado Springs, CO

The recent past of the Gulf of Mexico 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 1990 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 primarily from reserve growth (essentially extensions and new pool discoveries) in older fields, not from new field discoveries. Recent (19891998) 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 50% 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 (67 of 687) 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 broad depth slice, and by play (combinations of reservoirs by chronostratigraphic age and depositional style). Combining this analysis with an evaluation of drilling density by broad depth slice highlights the more likely areas for successful future exploration and development.

AAPG Search and Discovery Article #90908©2000 GCAGS, Houston, Texas