Study On The Geothermal Field Features And Coupling Numerical Simulaiton Bewteen SeePage And Temperature In Qiongbei Basin

Thermal groundwater is not only the water resources but also energy．Theexploitation and utilization of thermal groundwater resources has a stimulating effecton economic，social and environmental benefit．Qiongbei Basin geothermal fieldbelongs to the pore type layered thermal mineral water，the hot mineral water which ismainly contains in the fifth、sixth、seventh、eighth aquifer of the Loosely consolidatedrocks in Tertiary system．The hot mineral water is rich and it is benefit to people’shealth with most of the water quality is silicon confined water and radonmetasilicicacid fluoridated water．In recent years，with the rapid development ofHainan economy，especially the tourism industry，the demand of geothermal water inarea is increasing．Therefore，the further study of the sustainable development andutilization of geothermal field in Qiongbei Basin is imminent．This paper investigated the characteristics of Qiongbei Basin geothermal field，and discusses the genetic model of geothermal field．Qiongbei Basin geothermal fieldbelongs to the non-volcano type of medium-low heat convective system；The heatsource is made up of the decay of radioactive elements and mantle source，and mantlesource plays a leading role in the deep geothermalenergy；Thermal convection is theprincipal agent of heat transfer；The mean value of geothermal gradient is3.84℃/100m．This paper gave evaluate of geothermal fluid and geothermal energy deposits ofthe northern part of Haikou：the reserve of geothermal fluid is16.36×109m3、thenatural recharge ofgeothermal fluid is35189m3/d、the permit exploitation ofgeothermal fluid is30749m3/d、 and abundant geothermal energy is1625.28×1012kcal．According to the groundwater seepage theory and saturatedwater-bearing medium thermal transport theory，the coupling numerical simulaitonbewteen seepage and temperature which can describe the abundant regular andcharacteristics of geothermal water was established with the tool of FEFLOW．Themodel was inverted with the estimation-correction method．This paper also discussed the change regulation of the seepage field andtemperature field of geothermal field，which is under the method of increasing theexploitation of the single well and arranging the different group miningwell：①theborehole water level and temperature decreases with the increasing exploitation of asingle well．In general，the increasing exploitation mainly have a greater impact on the aquifer seepage field than the temperature field．②The water level decrease amplitudeis proportional to the decrease magnitude of the temperature in the same borehole，while in the different borehole，the result is opposite．③based on the group wellsarrangement of the same quantity，the decrease magnitude of borehole water level andtemperature is gradually slowing down belongs to the increasing of well space．④arranging of the different group wells，well quantity and single well exploitation havea greater impact on the water level and temperature than well space．...