USGS World Petroleum Assessment and the Total Petroleum System (TPS)

The critical geologic controls on petroleum distribution are encompassed by the Total Petroleum System (TPS) and were studied using this approach. Assessment Units (AU), within the TPS, were the basic units for assessment. Overall, 159 TPS and 270 AU were identified in 96 countries and 2 jointly held areas.

Of these, 149 TPS and 246 AU in 128 geologic provinces were quantitatively assessed. The assessed areas were those judged to be significant on a world scale in terms of known petroleum volumes, geologic potential for new petroleum discoveries, and political or societal importance. In the course of our geologic analyses, 24 AU were identified as containing continuous (nonconventional) resources, but these were not quantitatively assessed.

For each AU, allocations of undiscovered resources were made to the countries, geologic provinces, regions, and offshore areas (if any) involved. From these allocated portions, aggregations of estimates were made for higher levels such as to countries, geologic provinces, and groups of countries including the Organization of the Petroleum Exporting Countries (OPEC) and the Organization for Economic Co-operation and Development (OECD).

The United States was not reassessed in this study; estimates previously made by the USGS in 1995 and the Minerals Management Service in 1996 were used for comparative purposes. To access the data and assessments, see "pubs.usgs.gov/dds/dds-060/"