A PERSPECTIVE OF EXPLORATION FOR PETROLEUM

Abstract The first petroleum prospecting technique, based on the recognition of visible seeps of oil and gas, was rational and direct. The exhaustive application of megascopic geochemical prospecting led to diminishing returns, and a period of rule-o'-thumb prospecting ensued. Geological prospecting appeared on the scene, and, as a result, the anticlinal theory was evolved, to become a bone of contention for years within that profession. Eventually, however, the anticlinal theory was accepted by petroleum geologists, and so structural prospecting developed. The exhaustive application of structural prospecting by geological methods led to the discovery of many oil fields, but, eventually, diminishing returns ensued. A period of pessimism as to the nation's reserve followed, as rule-o'-thumb prospecting became the only possible prospecting procedure. Geophysical prospecting appeared on the scene in 1923, and was successful in the solution of a highly specialized problem without reliance upon depth estimations. With the passage of time, geophysical prospecting took on a structural complexion, and with the development of the reflection seismograph, a renaissance in structural prospecting took place. The geophysical phase of structural prospecting opened the vast basins for prospecting, and so revolutionized exploration for petroleum. However, geological prospecting did not experience a similar renaissance. Structural prospecting, in both its geological and geophysical phases, has been a rational but indirect prospecting method. Outstandingly successful, its exhaustive application is leading to diminishing returns. However, it has imposed a specialization upon both geological and geophysical prospecting which has stifled the natural development of geochemical prospecting from geological prospecting, has directed geophysical prospecting into an unduly narrow path, and, in permitting prospecting to greater depths, has resulted in an impasse wherein its success involves capital investments with prohibitive payouts. Though tacitly neglected in the past, there exists a geochemistry of a petroleum deposit, depending primarily upon the effects of the slow effusion of hydrocarbons through the sedimentary environment of the petroleum deposit throughout geologic time. Geochemical prospecting depends upon the chemical and physical measurement of one or more of the geochemical manifestations of a petroleum deposit, and the interpretation of the resulting data in terms of the local geology. Since structure is a necessary but not a sufficient condition for the accumulation of petroleum, geochemical prospecting is a rational and direct approach to exploration for petroleum, and in its turn will revolutionize prospecting to at least the extents that geological and geophysical prospecting did in the phases of structural prospecting which they initiated.