Study on the influence law of well location and water injection displacement on heat extraction performance of EGS

Abstract

The enhanced geothermal system (EGS) is the key to improving the heat production efficiency of hot dry rock (HDR). Due to the existence of EGS, the reservoir produces significant heterogeneity, so the optimal design of well location and injection rate has an important influence on the heat recovery effect of an EGS. To solve this problem, a calculation model for the heat output of an EGS under multifield coupling is established in this paper, and the influence of well location and injection rate on the heat recovery effect under different scales of EGS is deeply analyzed. The results show that the production well location and injection well displacement have a great influence on the heat recovery effect under different fracture‐network scales. The larger the size of the fracture network, the larger the effective utilization area of reservoir heat recovery and the better the effect of heat recovery. The closer the production well is to the fracture network and in the direction of the fracture network, the larger the effective utilization area of reservoir heat recovery is, and the better the effect of heat recovery is. The higher the injection well displacement is, the larger the effective utilization area of reservoir heat recovery is, and the better the heat recovery effect is. The research results have important guiding significance for the optimization of the scale, well placement, and water injection displacement of the EGS in the HDR reservoir.