Warm Moist Conditions Research Articles

The earlier struggles in petroleum geology were directed to solving theorigin and method of accumulation of petroleum. We are now fairly well agreedon those subjects. Most of us think that the great mass of petroleumcommercially produced comes from plants or animals, or possibly from both. Weare confident that the oil was not produced where it is now found but hasaccumulated in reservoirs of various kinds. The types of reservoirs arecertainly variable but they just as certainly follow definite geologic laws.Some of these types of reservoirs can be determined from surface study; otherscannot. We know, too, that these types of reservoirs (largely structures suchas anticlines, domes, and terraces) are much more widespread than the oilpools. In other words, there are many places where good sands and goodstructures exist but where oil is not found. It is the purpose of this paper, therefore, to attempt to analyze, from a regional standpoint, some of theconditions that control the presence or absence of oil pools and to group themin a regional way, hence the term "Petroliferous Provinces." The paperlays no claim to presenting new facts but attempts to group and classify theinformation that so many have expressed again and again. The essential factors for an oil field are petroleum, a reservoir material, andconditions under which the petroleum can enter the reservoir but cannot escapeexcept through the drill holes. The paper will first discuss the source ofpetroleum as it occurs in definite regions, then the regional arrangement ofreservoir strata, and finally the areal arrangement of structures. To have petroleum, there must be a source. Since living matter is consideredthe source of the petroleum, geological conditions must have been such thatliving organisms were abundant. Arid regions on the earth's surface have notgiven rise to living things in sufficient abundance to produce oil; similarly, too cold regions and saline inland lakes. The converse of this is that warmmoist conditions must prevail to produce an abundance of vegetable matter. AIME 065–22