白洋淀地表水回灌补给深部岩溶地热储层的水化学数值模拟  

Numerical simulation of the hydrochemistry for surface water injection into deep karst geothermal reservoirs in baiyangdian

作　　者：李胜涛[1,2,3,4] 施金宇 丁欣明 岳冬冬 路莹 LI Sheng-tao;SHI Jin-yu;DING Xin-ming;YUE Dong-dong;LU Ying(Key Laboratory of Groundwater Resources and Environment,Ministry of Education,Jilin University,Changchun 130021,China;Key Laboratory of Water Resources and Environment in Jilin Province,Jilin University,Changchun 130021,China;Center for Hydrogeology and Environmental Geology Survey,China Geological Survey,Tianjin 300309,China;Tianjin Geothermal Exploration and Development Engineering Research Center,Tianjin 300309,China;Yellow River Laboratory,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]吉林大学,地下水资源与环境教育部重点实验室,吉林长春130021 [2]吉林省水资源与环境重点实验室,吉林长春130021 [3]中国地质调查局水文地质环境地质调查中心,天津300309 [4]天津市地热勘查开发工程研究中心,天津300309 [5]郑州大学黄河实验室,河南郑州450001

出　　处：《中国环境科学》2024年第10期5830-5838,共9页China Environmental Science

基　　金：国家自然科学基金资助项目(42272284);地下水资源与环境教育部重点实验室开放课题资助(202207009KF);吉林省自然科学基金项目(20210101092JC);自然资源部中国地质调查项目(DD20221680)。

摘　　要：以雄安新区广泛开发的深部岩溶地热储层为研究对象,利用PHREEQC模拟了采用白洋淀地表水回灌补给主力开采地热储层-蓟县系雾迷山组岩溶地热储层后的水化学组分变化以及矿物溶解沉淀量.结果表明:回灌期内从回灌井向储层内部水化学类型依次为HCO_(3)·Cl-Na·Mg,HCO_(3)·Cl-Na,Cl·HCO_(3)-Na和Cl-Na型水,呈现由补给水向储层本源水过渡的变化趋势,主要受对流弥散影响,但Mg^(2+)、Ca^(2+)、HCO_(3)^(-)还受水岩反应和pH值等因素控制,变化趋势更为复杂;回灌后矿物的溶解沉淀现象主要发生在以回灌井为中心半径为0.5m的范围内,以方解石的沉淀和白云石的溶解最为明显,整体上会引起裂隙率降低,但其变化程度有限.对岩石渗透性影响不明显.基于回灌所引起的地热储层内部变化类型,划分了4种影响带,各影响带的范围大小依次为水化学影响带、渗流影响带、温度影响带和岩石渗透性影响带.Taking the extensively developed deep karst thermal reservoirs in Xiong'an New Area as the research object,this study uses PHREEQC to simulate the changes in hydrochemical components and the amounts of mineral dissolution and precipitation after injecting Baiyangdian surface water into the main exploited thermal reservoir—the Jixian Wumishan Formation karst thermal reservoir.According to the results,it can be seen that during the reinjection period,the chemical types of water from the reinjection well to the interior of the reservoir are sequentially HCO_(3)·Cl-Na·Mg,HCO_(3)·Cl-Na,Cl·HCO_(3)-Na and Cl-Na types,showing a transition from supply water to original reservoir water.This trend is mainly affected by advection and dispersion,but Mg^(2+),Ca^(2+),HCO_(3)^(-)are also controlled by factors such as water-rock reactions and pH,resulting in more complex trends.The dissolution and precipitation of minerals after reinjection mainly occur within a radius of 0.5m from the reinjection well,with the most obvious precipitation of calcite and dissolution of dolomite.These mineral reactions lead to a slight decrease in fracture porosity overall,but the change is limited and does not significantly affect rock permeability.Based on the types of changes in the geothermal reservoir caused by reinjection,four impact zones were delineated,namely the chemical impact zone,the seepage impact zone,the temperature impact zone,and the rock permeability impact zone,with the size of each impact zone decreasing in the order listed above.

关 键 词：地热回灌 地球化学模拟 水质演变 PHREEQC 堵塞 

分 类 号：X703.5[环境科学与工程—环境工程]