An Efficient Procedure for the Numerical Simulation of Geothermal Reservoirs

Abstract

Much computing time is spend when a numerical simulator is used to study a geothermal reservoir. An effort was made to develop and efficient methodology to solve to non linear system of equations in each time step of the initial value problem. Advantage was taken from the experience reported in the literature and some improvements were introduced: an algebraic manipulation to reduce the number of equations, a different treatment to equations for regions under and above the saturation curves and a simple procedure to shift from one treatment to the other. The resulting system of equations is almost linear and its exact solution is approached through Newton Ramphson corrections to the main variables and updating of other variables in each iteration. A computer code was developed and it was validates applying it to the six problems posed by the US Department of Energy in 1980. Computing times were significantly lower than those of other codes.