Impact of well placement on heat production from complex fracture networks in enhanced geothermal systems: A semi-analytical model

Understanding of the effective fracture path between a producer and an injector in complex fracture networks plays a key role in successful geothermal heat extraction from an enhanced geothermal system (EGS). Therefore, there is a need to investigate the impact of well placement on EGS heat extraction performance. An efficient thermal model is developed to simulate fluid and heat flow in fractured reservoirs with complex fracture networks. A general Green's function for fractures oriented at any angle is used, which reduces problem dimensions by one. The effect of fracture types on heat production performance is investigated and the impact of well placement on the efficiency of extracting geothermal energy is demonstrated. Results indicate that the rate of energy extraction depends on the number of backbone fractures connecting the injector and producer, emphasizing the need for well placement that creates more backbone fractures to allow for fluid circulation. These findings provide valuable guidance on well placement strategies to optimize geothermal heat extraction efficiency.