Enhancing geothermal wells by CO2 utilization

Abstract

Generally, geothermal production and injection wells of a geothermal doublet have different performances. To maximize energy production rate the well with higher performance should be used for production. One of the disadvantages of this option is the raise of costs for energy during production caused by increasing injection pressure over time. A potential method to enhance well performance by means of increase the permeability of carbonate rocks is the injection of CO2 enriched water during heat and/or electrical power production.Together with Geoenergie Bayern GmbH the Department of Hydrogeology of the Technische Universitaet Bergakademie Freiberg in cooperation with Hydroisotop GmbH have started a research project (LERWTG) to investigate the potential and the opportunities for CO2 injection at the geothermal pilot project Kirchweidach. This presentation will report first results about the feasibility and the requirements of CO2 water injection. Simulation results show the positive effects on permeability enhancement inside the carbonate reservoir.