Investigating Enhanced Geothermal Systems Feasibility in a Low-Permeability Sedimentary Formation

Abstract

Geothermal energy is a vital energy resource for the evolving energy mix. This is especially true with the potential inherent in enhanced geothermal systems to harness heat from hot rocks that do not have sufficient permeability and working fluids. This study presents a preliminary evaluation of EGS feasibility in sedimentary formations. We investigate the Schuler formation in the Brazos Basin. This formation is estimated to have temperatures between 200 and 250 oC. Preliminary petrophysical data indicated that the targeted layers have very low porosity with no natural fractures, low permeability, and no hydrocarbons, thus making them candidates for EGS. This study includes geological modeling, reservoir modeling, and production-reinjection scenarios simulation. We examined the impact of well spacing, well perforation at different levels, number of producers, and production time. Preliminary results indicate that more production wells resulted in better thermal performance. The wells with the same perforation level between the injector and producer resulted in better heat extraction.