The geological consensus is a useful method for estimating undiscovered oil and gas resources because the optimists balance the pessimists. Such group averages, however, are limited by the participants’ local expertise. Estimates of undiscovered oil and gas by petroleum geologists and engineers are much more conservative for areas where the experts have been humbled by dry holes and more optimistic wherever they have no direct experience. It is impossible to judge any expert’s degree of optimism or pessimism until his estimates are compared with those of a group of his peers. All group appraisals should be plotted on graphs, wherein each individual’s estimates are identified by a unique symbol to show the range of opinions. Estimates for virgin basins where no one has first-hand experience will normally be on the optimistic side.
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.