水文地球化学方法在地热资源勘查中的应用:以湖北省应城市为例  

Application of hydrogeochemical methods in geothermal resource exploration:A case study of Yingcheng City,Hubei Province

作　　者：卫兴 师红杰 陈松 尚建波 刘明亮 WEI Xing;SHI Hongjie;CHEN Song;SHANG Jianbo;LIU Mingliang(Hubei Key Laboratory of Petroleum Geochemistry and Environment,Yangtze University,Wuhan 430100,China;College of Resources and Environment,Yangtze University,Wuhan 430100,China;Hubei Key Laboratory of Resources and Eco-Environment Geology,Xiaogan Hubei 432000,China;Six Geological Team of Hubei Geological Bureau,Xiaogan Hubei 432000,China)

机构地区：[1]长江大学油气地球化学与环境湖北省重点实验室,武汉430100 [2]长江大学资源与环境学院,武汉430100 [3]湖北省地质局资源与生态环境地质湖北省重点实验室,湖北孝感432000 [4]湖北省地质局第六地质大队,湖北孝感432000

出　　处：《地质科技通报》2024年第3期68-80,共13页Bulletin of Geological Science and Technology

基　　金：国家自然科学基金项目(41902257);地热资源勘查与开发利用山西省重点实验室开放基金项目(SX202205);宁夏回族自治区重点研发计划项目(2022BEG03060);自然资源部深部地热资源重点实验室开放基金项目(KLDGR2022G01)。

摘　　要：地热流体水文地球化学研究在指示地热资源的形成机制、赋存环境以及预测地热资源有利勘查区等方面具有广泛应用。为了探究湖北省应城市地热系统的热源以及成因机制,并对其地热异常区进行圈定。基于研究区内地热水与浅层地下冷水的水化学及同位素特征,探讨了地热流体中主要组分的地球化学起源,评估了地热流体的热储温度。结合区内浅层地下冷水的温度与水化学数据,对地热异常区进行了圈定。研究结果表明,地热水水化学类型主要为SO 4-Ca型,地热系统主要的热储围岩为海相碳酸盐岩,通过地热温标计算热储温度约112.2℃。大气降水入渗和碳酸盐岩热储层中的水-岩相互作用是地热水中化学组分的主要来源。地热水的水化学和氢氧同位素特征指示地热水的补给来源为研究区西部山区的大气降水,大气降水由补给区入渗后向东南盆地中心不断运移,循环深度为3436.7~5030.2 m。通过与典型岩浆热源型地热系统的对比以及岩石样品中放射性元素的数据结果,得出应城地热系统是由地温梯度正常加热而形成的。结合区内浅层地下冷水的温度与水化学数据,最终圈定地热异常区位于应城市区西南陈河镇以北地区,但仍需考虑井深、人为污染等客观限制因素对圈定结果的影响。Hydrogeochemical studies of geothermal fluid are widely used to determine the formation mechanism and occurrence environment and predict favourable exploration areas for geothermal resources.[Objective]In order to understand the heat source and causative mechanisms of the geothermal system,the areas of geothermal anomalies are delineated in Yingcheng City,Hubei Province.[Methods]This study examines the geochemical origins of major components in geothermal fluid and evaluates the thermal reservoir temperatures of geothermal fluid based on the hydrochemical and isotopic characteristics of geothermal water and shallow groundwater.By integrating the temperature and hydrochemical data of shallow groundwater in the area,the geothermal anomaly zones are delineated.[Results]The results show that geothermal water hydrochemistry is mainly SO 4-Ca,and the main thermal storage enclosing rock of the geothermal system is marine carbonate rock,with a thermal reservoir temperature of approximately 112.2℃.Atmospheric precipitation infiltration and water-rock interactions in carbonate thermal reservoirs are the main sources of chemical components in geothermal water.The hydrochemical and hydrogen-oxygen isotope characteristics of the geothermal water indicate that the recharge source of the geothermal water is the precipitation from the mountainous areas in the western part of the study area.The atmospheric precipitation infiltrates from the recharge area and then continuously moves to the centre of the southeastern basin with a circulation depth of 3436.7 m to 5030.2 m.[Conclusion]Comparisons with the typical magma-heat source type of geothermal system as well as the results of the data of radioactive elements in the rocks,this study showed that the geothermal system of Yingcheng is formed by the heating of geothermal temperature gradient.Combined with the temperature and hydrochemistry data of the shallow underground cold water in the area,the final geothermal anomaly area is located in North of Chenhe Town Southwest of Yingch

关 键 词：水文地球化学 地热温标 地热异常 地热资源勘查 地热系统 应城市 

分 类 号：P314.3[天文地球—固体地球物理学] TK521[天文地球—地球物理学]