PMOD - A FLEXIBLE MODEL OF OIL AND GAS GENERATION, CRACKING, AND EXPULSION

A new computer program, PMOD, is used to develop and test a wide variety of global models of varied complexity for the generation and destruction of hydrocarbons from petroleum source rocks. Chemical reaction models are constructed interactively by supplying the empirical formula of the reactants and products, desired reactions, and reaction constraints. PMOD calculates stoichiometric coefficients that conserve elemental balance. The chemical reactions are integrated into two compaction and bulk-flow expulsion models in order to predict the amounts and compositions of products expelled from the source rock under geological conditions. A variety of published and unpublished experiments are used to show when various model types are required and to derive the parameters for the various models. This exercise provides a good means to compare the strengths and weaknesses of the various models and provides guidance on the types of information needed to calibrate them. Chemical properties calculated by PM OD for all models include apparent Rock-Eval parameters and other common geochemical measurements.