The abiogenetic petroleum origin hypothesis and its application in China

Abstract：The abiogenetic petroleum origin hypothesis argues that the crude oil and natural petroleum gas have no intrinsic connection with biological matter originating near the surface of the Earth. They are primordial materials which have been erupted from great depths. Therefore, they are renewable resources instead of non-renewable resources. The abiogenetic hypothesis has been supported by geological, physical and chemical evidence. Geologists found that no source rocks could form enormous volumes of hydrocarbons in many huge oil fields, and that therefore the most plausible explanation is abiotic deep petroleum. Besides, oil and gas have been found in basal rocks or in sediments directly above basal rocks, which could hardly be explained by biogenetic hypothesis. In chemical aspect, the Fischer–Tropsch process (or Fischer–Tropsch synthesis) has converted a mixture of carbon monoxide and hydrogen into liquid hydrocarbons. By thermodynamical analysis, the most significant conclusion is that methane is the only hydrocarbon that is stable at STP. The formation of normal alkanes from methane is thermodynamically possible only at pressures >30 kbar and temperatures >700°C which correspond to a depth of ~100 km below the Earth's surface (equivalent to the depth of the upper mantle). As a result, higher hydrocarbons such as those found in natural petroleum at the Earth's surface are metastable. By contrast, the formation of higher hydrocarbons from oxidized organic molecules is not thermodynamically possible under any conditions. Based on deep structure study, the authors hold that East China and West Pacific area, where mashroom cloud mantle is developed, are favorable for finding abiogenetic oil fields. The authors suggest drilling deep boreholes to evaluate oil potential and strengthening geophysical exploration, especially for basal structure.