In 1973 the U.S. Geological Survey initiated an oil and gas resource appraisal program having the following objectives:

1. To develop new methods for oil and gas resource appraisals that will permit the systematic collection and evaluation of basic geological and geophysical data from petroleum provinces throughout the United States and selected areas of the world;

2. to apply these methods to making detailed appraisals of the oil and gas resources, both offshore and onshore, of the United States and other specific areas of the world.

The procedures developed under this program facilitate the evaluation and use of all geological and geophysical data in reference to specific geologic provinces. As new and more detailed oil and gas data are compiled, particularly field and reservoir information on specific stratigraphic units and producing or prospective trends, the appraisal techniques become more sophisticated and their focus narrows from the total province to individual stratigraphic units. Finally, modified play-analysis techniques are employed for resource analysis, but still within the framework of each geologic province. A brief review is given of the resource appraisal procedures presently being used by the Resource Appraisal Group.

Interpretation of the geology of each potential petroleum province provides the basis for the resource appraisals discussed in this report. The geologic provinces of the offshore areas of the conterminous United States and Alaska are outlined and the basic geology is reviewed as known to date. The latest estimates of hydrocarbon potential for the offshore areas of the United States are reported in graphic form as probability distributions accompanied by updated maps and summary tables. Appraisals are made in all of the offshore areas to 200 m water depth. In areas which are thought to have greater petroleum potential, the appraisals are carried out to 2 500 m water depth.

A detailed report by Betty M. Miller and others, entitled “Geological Estimates of the Undiscovered Recoverable Oil and Gas Resources in the United States”, was published in 1975 (U.S. Geological Survey Circular 725). The report included resource estimates for all offshore provinces of the United States to 200 m water depth. Since the publication of this report, more comprehensive studies have been completed for the Gulf of Mexico out to 2 500 m water depth. The comprehensive resource appraisals of the offshore provinces of the eastern United States and Alaska that are currently in progress will incorporate more detailed geological and geophysical data than were available in 1975.