A Numerical Simulation Model for Thermal Recovery Processes

This study describes a model for numerically simulating thermal recovery processes. The primary focus is on the simulation of in situ combustion, but the formulation also represents fire-and-water flooding, steam flooding, hot water flooding, steam stimulation, and spontaneous ignition as well. The simulator describes the flow of water, oil and gas and includes gravity and capillary effects. Heat transfer via conduction, convection, and vaporization- condensation of both water and hydrocarbons is included. The rigorous but general nature of the simulator is obtained by employing conservation balance equations for oxygen, inert gases, a light hydrocarbon pseudo-component, a heavy hydrocarbon pseudo-component, water, coke, and energy. Vaporization-condensation is governed by vapor- liquid equilibrium using temperature- and pressure-dependent equilibrium coefficients. Four chemical reactions are accounted for: formation of coke from the heavy hydrocarbon component and the oxidation of coke and both heavy and light hydrocarbon components. Formulation details, numerical solution procedures, and computational results are presented. (39 refs.)