Analysis of Geological Conditions of Hot Dry Rock Evaluation

Abstract

Hot dry rock (HDR) geothermal resources as clean energy will have a significant role in the process of the future energy revolution. However, it is still difficult to obtain effective exploitation on a large scale because of its low energy abundance, deep burial, complex in-situ stress, and characteristics such as high thermal reservoir temperature, poor drillability, and difficulty of fracturing. At present, China is still in the stage of geothermal resources evaluation assisted by methodology guidance and experimental means, and no mature geothermal resources evaluation method has been formed, and there is a lack of systematic geothermal resource exploration technology system and evaluation methods, so there is still a big gap from the development of geothermal compared with western countries rich in geothermal resources. Based on the distribution characteristics of dry hot rock in China and the implementation status of EGS project, the author establishes the following evaluation ideas in geological HDR EGS site selection: heat source evaluation is the foundation, thermal reservoir evaluation is the core, caprock evaluation is critical, and fracture evaluation is a guarantee and carry out a comprehensive geothermal exploration and target selection method with engineering and geological integration to achieve a high match between geological and engineering sweet spot and minimize the geothermal development cost.