泥岩和砂岩的渗透率随围压变化特性的对比

Testing study on variational characteristics of the permeability for mudstone and sandstone with the change of confining pressure

通过试验,研究了围压升、降过程中泥岩和砂岩渗透率的变化特性。采用瞬态压力脉冲法测试泥岩的渗透率,采用定压法测试砂岩的渗透率。试验结果表明:围压加载过程中,泥岩和砂岩试样的渗透率均呈非线性减小,但泥岩的渗透率对有效围压的敏感程度远大于砂岩的;围压卸载过程中,泥岩和砂岩的渗透率发生不同程度的回升,但都不能恢复到原始值,砂岩渗透率的恢复程度大于泥岩的。

Based on permeability tests for mudstone and sandstone under loa ,the variational characterist ding-unloading of confining ics of the pressure permeability were studied. The permeability of mudstone was measured by transient pulse technique,and the permeability of sandstone was measured by constant pressure method.The test results reveal that both the permeability of mudstone and sandstone decreased nonlinearly with the increase of effective pressures.But the permeability sensitivity of mudstone to effective confining pressure was much stronger than that of sandstone.Both the permeability of mudstone and sandstone recovered when the pressure was reduced,but did not return to the original value even when the pressure was completely released.The recovery capability of permeability of sandstone was much stronger than that of mudstone.