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为研究低渗透岩石的非 Darcy渗流现象 ,采用FDES- 6 4 1三轴驱替评价系统进行了稳定渗流实验 ,测定了盐水和蒸馏水在低渗透砂岩和砾岩岩样中的渗流特性。岩样抽真空后水平放置于岩样夹持器中 ,通过多级驱替泵控制密闭岩样中水的渗流速度 ,所产生的压力差由压力传感器测定。结论为 :1)在空气渗透率非常低并且孔隙度非常小的砾岩中 ,明显存在着非 Darcy渗流现象 ,但由渗流曲线后退趋势所得出的启动压力梯度非常小 ,以致于在生产应用中可以忽略 ;2 )低渗透介质中的微粒运移是低速非 Darcy渗流现象存在的主要原因 ;3)岩石的非均匀性降低了岩石的渗透率。
In order to study the non-Darcy seepage phenomenon of low-permeability rock, steady-state seepage test was conducted by FDES-6 4 1 three-axis displacement evaluation system. The seepage characteristics of brine and distilled water in low-permeability sandstone and conglomerate samples were measured. After the sample is evacuated, the sample is placed horizontally in the sample holder. The multi-stage displacement pump controls the seepage velocity of the water in the closed sample, and the pressure difference is measured by the pressure sensor. The conclusions are: 1) In conglomerates that have very low air permeability and very low porosity, there is a clear non-Darcy seepage but the starting pressure gradient resulting from the tendency of the seepage curve to recede is so small that in production applications Negligible; 2) Particle migration in low-permeability media is the main cause of low-velocity non-Darcy seepage phenomena; and 3) Rock heterogeneity reduces rock permeability.