3D Poro-Thermo-Elastic Numerical Model for Analyzing Pressure Transient Response to Improve the Characterization of Naturally Fractured Geothermal Reservoirs

Abstract

This paper presents an innovative three-dimensional fullycoupled poro-thermo-elastic numerical model for simulation of pressure-transient response of naturally fractured reservoirs. One of the main purposes of the approach is to improve the reservoir characterization by reducing the uncertainties associated with subsurface fracture mapping. In this paper an innovative methodology of tracking the fracture backbone in microseismic cloud events is used to generate the subsurface map. The coupled fluid-flow and heat-transfer model is based on a hybrid of the single-continuum and the discrete-fracture approach. The 3D-numerical simulation model is validated against an analytical pressure-transient solution for a dual-porosity system and then applied to the Habanero enhanced geothermal system (EGS) in Central Australia. The results of the study also show that the simulated pressure change and pressure derivatives agree well with the field production data, which makes the innovative approach of tracking of fracture backbone in microseismic cloud events and simulation of pressure derivatives highly effective in predicting the fracture network along with its inherent properties.