摘要
【研究目的】冀中坳陷地区地热资源丰富,地下热水中氟分布特征及其风险评估对地热资源开发利用具有重要意义。【研究手段】本文以冀中坳陷地区地下热水为研究对象,通过分析砂岩热储层和碳酸盐岩热储层地热流体水化学数据,研究地热流体中氟的分布特征和富集规律,评价地热流体质量,提出地热流体开发利用相关建议。【研究结果】研究区地热流体以Na-Cl和Na-Cl-HCO_(3)型水为主,基本为碱性水,优势阳离子为钠离子,氟含量较高,尤其碳酸盐岩热储地热流体氟离子含量集中分布在7.5~9.5 mg/L,最高达13.9 mg/L;弱碱性环境、水温和水岩作用是影响研究区氟离子富集的主要因素,砂岩热储中氟离子浓度与Ca^(2+)、Mg^(2+)浓度呈显著负相关,而碳酸盐岩热储中其相关性并不显著。氟的富集受到萤石等含氟矿物的控制,砂岩热储地热流体萤石饱和指数全部小于零,而氟离子浓度较高的碳酸盐岩储层地热流体萤石饱和指数普遍分布在零附近。【结论】研究区高氟地热流体不能直接用于生活饮用水、农田灌溉和渔业用水,在进行地热资源综合梯级利用时解决地热尾水除氟问题至关重要。
This paper is the result of hydrogeological survey engineering.[Objective]The geothermal resources of Jizhong Depression are rich.The distribution characteristics and risk assessment of fluorine in geothermal waiter are of great significance to the development and utilization of geothermal resources.[Methods]This study takes the geothermal water in Jizhong Depression as the research object.The distribution characteristics and enrichment regularity of fluorine in geothermal fluid were studied by analyzing the hydrochemical data of geothermal fluid in sandstone and carbonate reservoirs,and the quality of geothermal fluid was evaluated,and furthermore some suggestions on the development and utilization of geothermal fluid were put forward.[Results]The results show that the geothermal fluids in the study area are mainly Na-Cl and Na-Cl-HCO_(3) type water,basically alkaline water,with high fluorine content.In particular,the concentration trend of fluorine ion content in the geothermal fluids of carbonate reservoir is 7.5-9.5 mg/L,and the highest is 13.9 mg/L.Weakly alkaline environment,water temperature and water-rock interaction are the main factors affecting fluoride ion enrichment in the study area.The F-concentration in sandstone geothermal reservoir has a significant negative correlation with Ca^(2+) and Mg^(2+) concentrations,while the correlation is not significant in carbonate geothermal reservoir.Fluorine enrichment is controlled by fluorite and other fluorine-bearing minerals.Fluorite saturation index of the geothermal fluids in sandstone reservoirs is all less than 0,while fluorite saturation index of the geothermal fluids in carbonate reservoirs with higher fluoride ion concentration is generally distributed around 0.[Conclusions]The high fluorine geothermal fluid in the study area cannot be directly used for drinking water,farmland irrigation and fisheries.It is of great importance to solve the problem of fluoride removal in geothermal tail water at the situation of conducting gradient utilization of geothermal resources in the study area.
作者
李曼
邢林啸
王贵玲
张薇
赵佳怡
靳孟贵
LI Man;XING Linxiao;WANG Guiling;ZHANGWei;ZHAO Jiayi;JIN Menggui(Institute of Hydrogeology and Environmental Geology,Chinese Academy of Geological Sciences,Shijiazhuang 050061,Hebei,China;Technology Innovation Center of Geothermal&Hot Dry Rock Exploration and Development,Ministry of Natural Resources,Shijiazhuang 050061,Hebei,China;China University of Geosciences(Wuhan),Wuhan 430074,Hubei,China)
出处
《中国地质》
CSCD
北大核心
2023年第6期1857-1870,共14页
Geology in China
基金
中国地质调查项目(DD20190555)资助。
关键词
氟
地下水
地热尾水除氟
碳酸盐储层
地热流体质量评价
水文地质调查工程
冀中坳陷
河北省
fluorine
groundwater
defluorination of geothermal tail water
carbonate reservoir
geothermal fluid quality evaluation
hydrogeological survey engineering
Jizhong depression
Hebei Province
