井周高渗透性多孔介质对多筛孔井修复效果的影响

IMPACT OF SURROUNDING HIGH-PERMEABLE POROUS MEDIA ON REMEDIATION EFFICIENCY OF MULTI-SCREEN WELLS

为探究井周介质非均质性对多筛孔井修复地下水效果的影响,利用二维数值模拟,通过在井周设置高渗透性透镜体并改变其位置、尺寸和渗透系数,探究井周存在高渗透性多孔介质的情况下多筛孔井的修复效率和最优注入间距。结果表明:井周高渗透性透镜体的存在及其位置、尺寸、渗透系数的变化均影响多筛孔井的修复效率,其结果取决于溶质羽因透镜体产生的聚集和绕流程度;井周高渗透性介质的存在可显著提升修复效率;多筛孔井最优注入间距因井周非均质性的存在而改变,一般来说,井周高渗透性多孔介质的存在将增大最优注入间距。该研究结果可为利用多筛孔井在非均质含水层中的修复提供理论指导,并为进一步提高多筛孔井修复效率提供一种新思路。

To investigate the impact of surrounding heterogenous media on the remediation efficiency of the multi-screen wells,two-dimensional numerical simulations were performed.In the numerical model,high-permeable lenses were constructed around the well and the location,size and hydraulic conductivity of the lenses were changed in different setups.The results showed that the surrounding high-permeable lenses and their position,size and hydraulic conductivity had impact on the remediation efficiency of the multi-screen wells,and its value depended on the effect of flow focusing and meandering introduced by the high-permeable lenses.The high-permeable porous media surrounding the well could significantly enhance remediation efficiency.The optimal injection interval changed due to the existence of heterogeneity surrounding the well.In general,optimal injection interval was enhanced with the surrounding high-permeable porous media.This study provides theoretical instruction for the groundwater remediation using multi-screen wells in heterogeneous aquifer.Furthermore,it offers a new idea on further enhancing remediation efficiency by the multi-screen wells.