单裂隙增强型地热储层的产热能力数值模拟分析OA

Influenced by anisotropic in-situ stress and natural fractures,deep geothermal reservoirs often exhibit preferential fracture development during hydraulic stimulation,resulting in the formation of artificially created geothermal reservoirs that approximate a single-fracture system.Whether such single-fracture geothermal reservoirs can provide commercially viable thermal energy remains a topic of considerable debate.This paper,based on the assumption of a single-fracture geothermal system,investigates the system's heat generation capacity under the influence of varying fracture structural parameters and well location parameters.The simulation results indicate that reducing the fracture aperture from 1.0 to 0.1 effectively delays thermal breakthrough and decreases the heat loss rate by 37.7％.Furthermore,increasing the distance between injection and production wells from 141 m to 424 m,or optimizing the injection flow rate from 1 m3/min to 3 m3/min,enhances the system's heat recovery capacity by 3.1 MW and 10.6 MW,respectively.With detailed characterization of fracture structures and optimization of well field configurations,single-fracture geothermal systems can achieve favorable thermal recovery performance.Assuming a horizontal fracture with an aperture less than 0.1 mm,the system can maintain a thermal loss rate of less than 15％over 30 years of operation and sustain a heat extraction capacity above 12 MW,under the conditions that the well spacing exceeds 420 m,the injection rate is below 1 m3/min,and the injection temperature is above 30.0℃.