A Novel Numerical Method for Geothermal Reservoirs Embedded with Fracture Networks and Parameter Optimization for Power Generation

Geothermal recovery involves a coupled thermo-hydro-mechanical (THM) process in fractured rocks. A fluid transient equilibrium equation, considering thermal conduction, convection, and heat exchange, is established. The evolution of the reservoir permeability variance fracture aperture due to change stress field are derived simultaneously. THM coupling accomplished through iterative hydromechanical thermo-hydro processes. To overcome difficulty geometric discretization, three-dimensional coupler model embedded with discrete networks, using zero-thickness surface line elements simulate fractures injection/production wells, established evaluate geothermal production. reliability method verified by case study. Then, this applied influence topological characteristics networks on temperature extraction effectiveness. results show that power generation efficiency depletion rate significantly affected injection–production pressure. Injection wells production pressures higher than initial pressure can be used increase generation, but consumption energy loss significant rapid. achieve better benefits for system, an optimization algorithm based simultaneous perturbation stochastic approximation (SPSA) proposed; it takes as objective function, corresponding program developed MATLAB optimize position values each well. transfer entire EGS becomes more uniform after optimization, greatly improved.