Optimization of pattern of well in hot dry rock fractured reservoirs through numerical simulation

Abstract

Objective An enhanced geothermal system (EGS) is a crucial means of extracting thermal energy from hot dry rock reservoirs, and the pattern of well plays a key role in influencing heat extraction efficiency. Currently, there is limited research on pattern of well considering fractured reservoir exploitation models. Methods This paper establishes a numerical model for heat extraction from hot dry rock fractured reservoirs and analyses the impact of four different patterns of wells on EGS heat extraction performance through a comparative analysis of the temperature decrease of the bedrock, heat extraction rate, production temperature, and heat extraction power. Results The results indicate that, compared to vertical wells, horizontal wells have a larger area for fluid heat exchange, allowing for more efficient heat development between fractures. After 30 years of production, considering the case of hydraulic fracturing fracture connectivity, the one injection and two production schemes of horizontal wells exhibit the highest heat extraction efficiency. In the vertical well direction, the temperature influence range is approximately 690 m, with an average temperature decrease of 38.09 K in the bedrock, a heat extraction rate of 24.42%, and a heat extraction power of 3.5 MW. Conclusion The research results provide a theoretical reference for enhancing the heat production of geothermal systems and achieving efficient and sustainable development of hot dry rock resources.

Keywords

• hot dry rock
• fractured reservoir heat extraction
• enhanced geotherm system(egs)
• numerical simulation
• pattern of well
• horizontal well
• sensitivity analysis