Analysis On Thermal Control Factors And Resource Potential Of Geothermal Fields In Xianxian County

With the continuous increase of energy demand and the continuous reduction of traditional energy reserves,clean energy has been gradually valued by people.In the case of increasingly serious environmental pollution caused by traditional energy,in order to healthy living environment and sustainable economic development,we urgently need energy transformation and the development and utilization of clean energy.Geothermal resource is one of the most valuable new energy resources,which plays an important role in alleviating environmental pollution and sustainable economic development.Xian county Geothermal Field is located between Jizhong Depression and Cangxian Uplift.It is rich in geothermal resources and has the characteristics of shallow burial,high temperature,large reserves and excellent location.In order to study the thermal control conditions and geothermal resources potential of the geothermal field in xian county,this paper analyzes the deep geological structure characteristics of the geothermal field in xian county from the aspects of magnetic field,gravity field and electric field through the existing regional geological data and drilling data in the study area.The hydrochemical characteristics of the thermal reservoir are obtained,and the hydrochemical type is mainly Cl-Na type.According to the geothermal well temperature measurement data,the geothermal gradient is calculated,and the isoline map of geothermal temperature and geothermal gradient is drawn.It is concluded that the horizontal geothermal gradient is higher in Cangxian uplift area and lower in Jizhong depression area,and the vertical geothermal gradient is a heat transfer process dominated by conduction.Based on the characteristics of geothermal field,the control factors of geothermal field in xian county are analyzed from the aspects of heat source,hot water supply,groundwater activity,lithology and geological structure.COMSOL Multiphysics software is used to carry out numerical simulation on geothermal field to obtain geothermal isotherm distribution map and analyze the influence of fracture on heat conduction.Based on the characteristics of geothermal field and thermal fluid chemistry,the genetic mechanism of geothermal system is analyzed.Under the normal regional thermal background(65m W/m²),atmospheric precipitation is taken as the main recharge water source,and underground water absorbs the heat of surrounding rock to upward flow along the fault during deep activities,which is restricted by the structural pattern and forms geothermal anomaly.According to the structural characteristics and different thermal reservoirs,the study area is divided into different zones,and the geothermal resources are evaluated by the methods of thermal storage and recoverable coefficient.The total geothermal resources of Xianxian geothermal field are 5169.74×10¹⁶J,the geothermal fluid storage is 97360.73×10⁶m³,and the exploitable geothermal resources are 4868.04×10⁶m³.Based on the analysis and research of the thermal control factors and resource potential of the geothermal field in Xianxian County,the appropriate development and utilization plan is made,and the comprehensive utilization and cascade utilization are adopted to realize the best use of resources.To some extent,it alleviates the environmental pollution of traditional energy in the study area,and plays a guiding role in the development and utilization of similar geothermal fields.