The set of 4 CD-ROM discs, documents the U.S. Geological Survey World Petroleum Assessment 2000 and includes estimates of the quantities of conventional oil, gas, and natural gas liquids outside the United States that have the potential to be added to reserves in the next 30 years (1995 to 2025). Two components, undiscovered resources and reserve growth, are estimated. One hundred and forty nine total petroleum systems and two hundred and forty six assessment units (subdivisions of total petroleum systems) were assessed. The supporting maps, data, text and tables produced by the World Energy Assessment Team during this five-year project (1995-2000) are included in the set.