郴州市许家洞地区地热资源特征及资源量评价

Evaluation of Characteristics and Reserves of Geothermal Resources in the Xujiadong Area,Chenzhou City

为查明郴州市地下热水资源的特征及储量,本文选取许家洞地区两个典型地热田,通过地热地质调查、水质测试等方法调查了研究区的地质条件、地热流体场特征、地下热水水化学类型。基于上述研究开展了许家洞地区地热资源储量的分析评价。研究结果表明:(1)区内地下热水受断裂构造控制,是入渗地下水沿着断裂构造在深部循环过程中吸收隐伏岩体中的热能形成的;(2)地下热水水化学类型主要为HCO_(3)-Ca型、HCO_(3)-Ca·Na型或HCO_(3)·SO_(4)-Ca·Mg型,为低温、无色透明的弱碱性水;(3)热水的主要补给来源为大气降水,水分入渗后主要沿区内发育的北东向断裂构造(F24、F7、F25、F8)运移到一定深度,地下水逐渐增温变成地下热水,在断裂交汇处沿着不均匀发育的岩溶裂隙系统向上运移,以温泉形式出露于地表;(4)研究区地下热水每年可提供热能约3.23×10^(8)MJ,每年可节约标准煤资源约1.18×10^(4)t。该研究成果对郴州市地热资源的合理开发利用具有重要指导意义。

In order to find out the characteristics and reserves of geothermal water resources in Chenzhou City,two typical geothermal fields in the Xujiadong area were selected,and their geological conditions,characteristics of geothermal fluid field,and hydro-chemical types of geothermal water were also investigated by means of geothermal geological survey and water quality test.Based on the above research,an analysis and evaluation of geothermal resource reserves in this study area was conducted.The results show that:(1)The geothermal water is controlled by fault structure and is formed by the infiltrated groundwater absorbing heat energy from buried rock mass during deep circulation along fault structure.(2)The main hydro-chemical types are HCO_(3)-Ca type,HCO_(3)-Ca·Na type or HCO_(3)·SO_(4)-Ca·Mg type,and the geothermal water is low-temperature,colorless and transparent weakly alkaline water.(3)The main supply source of geothermal water is atmospheric precipitation.After water infiltration,it migrated to a certain depth along the developed NE fault struc-ture(F24,F7,F25,F8),and during this process,it absorbed heat energy and gradually warms to form hot water.Afterwards it migrated upwards along the unevenly developed karst fissure system at faults intersection,and finally emerged on the surface as hot springs.(4)The geothermal water can provide about 3.23×10^(8)MJ of thermal energy annually in this research area,which can save about 1.18×10^(4)t of standard coal resources per year.The research results are important for guiding the rational development and utilization of geothermal resources in Chenzhou City.