【摘要】 以地热砂岩回灌中存在的物理堵塞问题为研究背景,开展微小颗粒在含水多孔介质内运移特性的渗流实验研究。通过圆管中填充玻璃珠构造多孔介质实验段,搭建含微小颗粒流体在多孔介质圆管内的渗流特性实验台。对比研究颗粒直径d_p分别为12.96和22.81μm、多孔介质平均粒径D_p分别为408.9和659.2μm、含颗粒流体质量浓度在0.3~2.0 g/L范围下,颗粒在多孔介质界面处及内部各段沉积的影响规律。实验结果表明:当d_p=12.96μm时,颗粒在多孔介质内部的沉积量远大于在界面处的沉积量;当d_p=22.81μm,流体浓度C<0.3g/L时二者相差不大;C>0.5 g/L时颗粒在介质内部的沉积量小于界面处沉积量,且二者差值随着流体浓度的增大而增大,说明此时"筛滤"作用产生。研究结果可为下一步的数值模拟提供实验验证。更多还原

【Abstract】 In this work,we carried out experimental study on migration of micro particles in porous media,taking physical clogging in sandstone during geothermal reinjection as research background.Underground aquifer was simulated by filling the cylindrical pipe with spherical glass beads. Particle deposition in the porous and at the fluid/porous media interace was respectively analyzed,with the particle size d_pvalues of 12. 96 and 22. 81 μm,porous medium particle diameter D_pvalues of 408. 9and 659. 2 μm,and carrier fluid concentrations ranging from 0. 3 to 2. 0 g/L. The results shows that the amount of particles deposited inside the porous medium is much larger than at the interface of porous medium when d_p= 12. 96 μm. However,when d_p= 22. 81 μm,there is little difference between the two depositions as C < 0. 3 g/L,whereas this difference increases as the concentration of the carrier fluid increases,indicating that more particles deposited at the fluid/porous medium interfaces and the "sieve " effect occurs. The results would be useful in the next numerical simulations.更多还原