Preliminary Data on the Mechanisms and Kinetics of the Formation of Petroleum in Sediments. Computer Simulation of a Reaction Flowsheet

Recent studies investigated the formation of oil compounds in sediments, as a function of burial depth, in some geological settings of the Toarcian in the Paris Basin and the Mio-Pliocene in California. In the formations examined, these observations served to identify favorable zones where oil was generated by organic matter. To extend these results to other formations and other basins, an attempt was made to fit them into a synthetic reaction flowsheet and to determine the kinetics corresponding to this flowsheet. The computer simulation of the way in which the reaction flowsheet evolves helps to calculate the amount of oil formed from one gramme of original organic matter, at any point of a basin. The necessary data are the geological reconstruction of the burial history and a set of constants representing the type of original organic matter concerned.In the case of the Toarcian in the Paris Basin, the results show close agreement between the valuescalculated in this manner and the values actually observed.This also clarifies the problem of the period and the oil formation rate, allowing comparison with the ageof the structural movements which determined the formation of the traps