Journal of Petroleum Geology, Vol.8, No.2, pp. 221-228, 1985

©Copyright 2000 Scientific Press, Ltd.

A GRAPHICAL METHOD FOR STUDYING MODELS OF OIL GENERATION

W. H. Burke and D. U. von Rosenberg*

*Mobil Research and Development Corporation, PO Box 819047, Dallas, TX 75381, USA.

Abstract

Various types of mathematical models are used to represent the natural processes of oil generation from kerogen. One type models the generation process as consisting of several independent, parallel, first-order reactions, each of which is defined by an Arrhenius relation. We present here a graphical method for studying predictions of models of this type. Each point on a plot of log10 A versus E represents a reaction, and the order of occurrence of these reactions with increasing temperature is shown by rotating a line across the graph. The greatest value of the plot is that it enables one to see at a glance many of the deductions that follow from assuming the correctness of a particular model and also to see quickly many of the effects of changing the model's assumptions. As an example, we present a plot of this type for reactions of Tissot and Espitalié (1975) Type II kerogen undergoing natural maturation, and also undergoing laboratory pyrolysis. For comparison, we include numerical computations for these reactions.