EGS design and production capacity evaluation of hot dry rock considering complex cracks

• Published in: Journal of Applied Science and Engineering Vol. 29; no. 2; pp. 347 - 358
• Main Authors: Yong Liu, Chunyu Yu, Zhongkuo Lin, Xiao Liu, J Zhang
• Format: Journal Article
• Language: English
• Published: Tamkang University Press 2026
• Subjects: capacity evaluation; complex crack; enhanced geothermal system; fracturing method
• ISSN: 2708-9967; 2708-9975
• DOI: 10.6180/jase.202602_29(2).0010

This paper analyzes the heat extraction performance of EGS (Enhanced Geothermal Systems) under complex fractures based on Darcy’s law and porous media heat transfer theory, and investigates the effects of reservoir parameters, injection and extraction parameters, fracture distribution, fracture thickness and well placement parameters on the production performance of EGS under complex fractures. The results show that: with the increase of EGS operation time, the cold front of the thermal storage temperature field expands continuously, and the temperature of the production wells decreases at a faster rate, while the changes around the pressure field are not significant; when the injection temperature increases continuously, the higher the injection temperature is, the higher the production temperature is, and the cumulative heat extraction rate of the system is lower; when the injection and extraction well spacing increases continuously, the heat extraction performance of the system and the pressure difference between injection and extraction wells increase subsequently, and the heat extraction performance of the system decreases with the injection volume The thicker the artificial fracture, the lower the production temperature, the lower the heat extraction performance of the system with the increase of the thickness of the artificial fracture, the thicker the natural fracture, the higher the production temperature of the system; the heat extraction performance of the system with horizontal fracture is higher, and the pressure of the vertical fracture around the injection well is larger.