Bulletin of the Geological Society of Malaysia, Volume 33, Nov. 1993, pp. 5-19
US Geological Survey, Reston, VA 22092, USA
Abstract: With some confidence, we are now in a position to estimate the location, geologic rationale, and general quantities of the world petroleum resources. Clearly, the last barrel has not been discovered, but the broad geologic factors that control large occurrences are recognized and incorporated into an hypothesis of Petroleum Realms which recognizes three broad regions of the world (Boreal, Tethyan, and South Gondwana - from north to south), wherein climate conditions, over geologic time, controlled the quality of source rock, the presence or absence of carbonate reservoir rock, and the existence of salt seals. Because South Gondwana has experienced such low latitude conditions since post Jurassic time, it is poorly endowed with petroleum resources. A fourth Petroleum Realm, the Pacific Realm, likewise is poorly endowed with petroleum resources but for reasons of tectonism and volcanic activity. As an outgrowth of these controlling geologica/climatic conditions, combined with analyses of exploration history and estimates of Undiscovered Resources, we would propose that, by the year 2010, more than 50% of the world‘s oil will be produced by OPEC, up from 33% in 1990.