Technical Advancements and Development Suggestions of Geothermal Heat Reservoir Stimulation in Deep Formations

China has abundant geothermal resources in deep formations. Due to the characteristics of high temperature, high hardness, high stress, and high operation pressure, it is extremely difficult to economically utilize its heat energy through heat reservoir stimulation. A large number of geothermal resources in deep formations, such as high-temperature sedimentary rocks and dry hot rocks, have not been utilized on a large scale due to technical and economic limits. The latest research advancements of geothermal heat reservoir simulation in deep formations in China and overseas was summarized. It was found that the conventional injection and production mode of vertical wells or inclined wells and the general fracturing method failed to meet the needs of geothermal economical development in the deep formation. Therefore, suggestions were proposed, i.e. extensively developing combined injector and producer pattern of“vertical wells+horizontal wells”or“horizontal wells+horizontal wells”+staged fracturing technology, supporting high temperature-resistant tools and materials, and fracture system quantitative characterization technology, so as to ramp up China’s energy transformation and facilitate the achievement of “carbon peaking and carbon neutrality” goals.