矿井水深层回灌过程量质耦合模拟分析  

Coupling simulation of groundwater dynamics and solute transfer in the process of deep reinjection of mine water

作　　者：赵春虎 杨建 王世东 周建军 许峰 刘基 ZHAO Chunhu;YANG Jian;WANG Shidong;ZHOU Jianjun;XU Feng;LIU Ji(Xi’an Research Institute Co.Ltd.,China Coal Technology and Engineering Group Corp.,Xi’an 710077,China;Shaanxi Key Laboratory of Prevention and Control Technology for Coal Mine Water Hazard,Xi’an 710077,China)

机构地区：[1]中煤科工集团西安研究院有限公司,陕西西安710077 [2]陕西省煤矿水害防治技术重点实验室,陕西西安710077

出　　处：《煤田地质与勘探》2021年第5期36-44,共9页Coal Geology & Exploration

基　　金：陕西省自然科学基础研究计划项目(2020JM-715);天地科技股份有限公司科技创新基金项目(2018-TD-MS069,2018-TD-QN052)。

摘　　要：矿井水深井回灌是矿井水“转移存储”处理的主要形式,根据鄂尔多斯盆地煤矿区地质和矿井水特征,从回灌目的层地下水与矿井水的匹配性、上下岩层的隔水性、回灌层的渗透性以及封闭性角度提出了矿井水回灌目的层选取依据。并以地下水达西定律和Dupuit理论为基础,建立极坐标系完整注水井稳定流数学模型,得出在稳定注水条件下,回灌量与注水层渗透系数、厚度、回灌压力、水位埋深以及回灌井直径正相关,与影响半径负相关,与回灌层埋深无关。提出了矿井水深层回灌水动力和溶质运移耦合仿真模型构建方法,并以矿井水回灌试验案例为分析对象,模拟得出矿井水回灌过程中含水层水压形成以注水井为中心的“高位水丘”,且注水压力越大,回灌量增加较为明显,模型分析结果与现场试验结果基本一致。溶质运移范围形成以注水井为中心的“圆柱状”弥散形态,特征离子浓度沿回灌井两侧变化剧烈,回灌层特征离子浓度被迅速稀释,随着时间的延伸,弥散稀释范围增加相对较小,说明矿井水回灌对深部高浓度含水层地下水水化学影响程度不大,研究成果可为西部煤矿区矿井水高效回灌处理提供科学依据。The deep well reinjection of mine water is a main form of“transfer storage”treatment of mine water.According to the geological and mine water characteristics of the coal mine area in Ordos Basin,the paper puts forward the basis for selecting the target layer of mine water reinjection from the perspective of good matching between groundwater and mine water in the target layer of reinjection,the water isolation of upper and lower strata,permeability and sealing of the reinjection layer.Based on Darcy’s law of groundwater and Dupuit’s theory,a mathematical model of steady flow of water injection well in polar coordinate system is established.It is concluded that under the condition of steady water injection,the reinjection quantity is positively correlated with the perme-ability coefficient,thickness,reinjection pressure,water level burial depth and reinjection well diameter of water injection layer,negatively correlated with the influence radius,and it has nothing to do with the burial depth of water injection layer.The construction method of coupling simulation model of groundwater dynamics and solute transfer in the process of deep mine water reinjection was put forward,and mine water reinjection test was taken as the analysis object.The simulation results show that the formation of water injection well is the“high water mound”in the process of high-pressure mine water reinjection;the higher the injection pressure is,the more obvi-ous the reinjection amount is.The model analysis results are basically consistent with the field test results.More-over,the solute transfer range forms a“cylindrical”dispersion shape centered on the water injection well;the ion concentration changes sharply along both sides of the reinjection well;the ion concentration of the aquifer is rap-idly diluted.With the extension of time,the increase of dispersion dilution range is relatively small,which indi-cates that the relative recharge of mine water has little effect on groundwater chemistry of deep high concentration aqui

关 键 词：矿井水处理 回灌 溶质运移 渗流 数值模拟 

分 类 号：TD32[矿业工程—矿井建设]