Application of a Matrix-Fracture Transfer Pseudofunction in Geothermal Reservoir Simulation

Abstract

A fine-grid, single porosity model of a matrix-fracture system was used to visualize the pressure response and mass transfer mechanisms in a vapor-dominated geothermal reservoir. The observed pressure response and saturation distributions were used to generate a pseudofunction representing the product of vapor phase relative permeability and matrix-fracture transfer shape factor for a dual-porosity model. The pseudofunction was found to be a function of vapor saturation. It was used in place of the gas relative permeability curve. With the application of the pseudofunction, the dual-porosity model produced pressure decline trends similar tothose observed in the fine-grid models. The pseudofunction approach was successfully applied in the history matching of a single Geysers producing well. The TETRAD simulation code was used in this study.