Study on the geothermal production and reinjection mode in Xiong County.

The large karst geothermal field of Xiong County, which is located to the south of geothermal field in Niutuozhen, features huge geothermal resources and favorable condition for development and utilization. Because of the long-term extensive production, the pressure of geothermal reservoir continues to decline and some geothermal wells even face the danger of scrapping. To relieve the fall in pressure of geothermal reservoir and achieve the sustainable development and utilization of geothermal field in the long run, reinjection experiment is conducted in the geothermal field of Xiong County and a three-dimensional hydrothermal coupled numerical model was constructed. The reinjection experiment showed that the mode of one production well and one reinjection well can be achieved in this geothermal field. The numerical simulation is used to forecast and compare the change in pressure field and temperature field under different production and reinjection modes and concludes that the most opotimized production and utilization mode is the concentrated production-reinjection mode, and the most opotimized production-reinjection combination mode is the shallow production and shallow reinjection mode which can ensure the sustainable development and utilization of geothermal resources in the long run.