THE MECHANISM OF PETROLEUM FORMATION

Abstract

The totality of geochemical indicators of the formation of petroleum from the disseminated organic matter of sedimentary rocks is the fundamental evidence proving the biogenic origin of oil and gas. Geochemical modeling of the processes of transformation of organic matter into petroleum hydrocarbons indicate that oil and gas are predominantly products of thermocatalytic transformation of the original organic material. A substantial role is also played by biochemical processes of formation of petroleum hydrocarbons during the early stages of lithogenesis. A large amount of data on the composition and distribution of organic matter in different petroleum-source rocks, formation water, etc., have been gathered during the present phase of investigation. It has been established that the formation of petroleum hydrocarbons in insoluble organic matter and its quantitative rate are clearly associated with the genetic type and grade of metamorphism of the original organic matter and with the depth of subsidence of the enclosing sediments. The results of these studies are of great theoretical and practical significance. It is sufficient to state that on the basis of these data, it is possible to determine more objectively the mechanism of formation and primary migration of the hydrocarbons from the disseminated organic matter in themore » sedimentary rocks. 10 references.« less