Hydraulic and thermal interaction between rock and fluid in an artificial geothermal reservoir

The paper aims at developing a mathematical model to describe the hydraulic and thermal behavior of an artificially created reservoir (a.k.a. HDR). The investigated system consists of an injection well, through which high-volume water is injected downhole, an artificially created fracture system used to extract the geothermal heat of the earth, and a production well through which heated water reaches the surface. The energy content of the produced water is removed by suitable surface heat exchangers. Spent water is re-injected through the injection well thus making the system a closed one. The computer program developed by the authors is used to investigate the feasibility of the described process in Hungary. The authors select the site best suited for such kind of heat extraction, then, using several assumed fracture configurations calculate the hydraulic and thermal parameters of the proposed system.