Numerical Simulation and Design Optimization of Large-Scale Geothermal Production Based on a Multiwell Layout in Xianxian Geothermal Field

Large-scale geothermal production based on a multiwell layout has been promoted by the development of clean energy. However, the theories about the effects of this geothermal production pattern on the temperature field of geothermal reservoirs are yet to be improved, which hinders the design optimization of the deployment schemes of geothermal wells. This study proposed a 3D geothermal multiwell simulation method covering the heat transfer in wellbores by introducing the geothermal well theory of 1D line elements, thus improving the calculation efficiency without reducing the calculation accuracy. By taking the geothermal development using multiple wells in the Xianxian geothermal field, China, as an example, this study firstly analyzed the evolution of the temperature field in geothermal reservoirs during the geothermal exploitation based on a multiwell layout. Then, it revealed the influencing mechanisms of geothermal multiwell effect, reinjection depth, and well spacing on the thermal breakthrough of exploitation wells. Finally, it proposed an optimized design method for the geothermal development based on a multiwell layout. All these will provide scientific support for the large-scale geothermal production based on exploitation-reinjection combination using multiple wells.