The World Energy Resources Program of the ILS. Geological Survey applies an assessment technique to international petroleum provinces that was established initially for purposes of domestic analysis. Additions to the procedures that permit quasi quantitative evaluations of exploration maturity are being evolved for the assessment process, as are methods of disaggregating the assessment into a field size distribution. Program results to date indicate that while oil reserves are high, they are also declining steadily because of continued production in excess of discovery such that a deficit of ~ 70 billion bbl has accumulated in the 10-year period between 1971 and 198L More disturbing than the discovery/production deficit, however, is the assessment that the distribution of world crude oil has been established, and no new areas with undiscovered resources of > 20 billion bbl of oil have a most likely probability of being discovered.
Figures & Tables
There is a continual need to update estimates of oil and gas resources remaining to be discovered, and also to refine the methodologies for making these assessments. In 1974, AAPG sponsored a research conference dealing with the above topics, and many of the papers presented there were published in AAPG Studies in Geology 1. As a follow-up to that volume, a U.S. Geological Survey workshop was held in 1983, and many papers from talks presented there, in addition to several other papers, are contained within this volume. The 22 papers have been grouped into two types: those describing methodologies for evaluating resources and those presenting assessments of both conventional and unconventional resources.