Heat Mining Process of Enhanced Geothermal Systems, a Numerical Study of Gonghe Basin, China

Abstract

Enhanced Geothermal System can achieve the development and utilization of Hot-dry Rock, which will be one of the most important resources in the future. There are very abundant Hot-dry Rock resources in Gonghe Basin, Qinghai province. There are complex water-thermal coupling processes when water flow in the reservoir, and power generation capacity dependents on the EGS operation scheme. Based on the deep geological condition of Qiabuqia in Gonghe Basin, we established a numerical model to characterize the hydrothermal features of EGS, researched the temporal and spatial distribution of temperature field, pressure field, and analyzed the influence of injection temperature and flow rate on heat extraction rate. The results show that the maximum heat extraction rate can be 11Mw under the base scheme, reservoir life is 22 years. Heat extraction rate will increase by about 10% as 10oC increase of injection temperature, while reservoir life remain the same. Increased flow rate will lead to a greater rate of heat extraction but shorter reservoir life. The research results can provide a theoretical basis for the implementation of the EGS Project in the future.