围压对峰后岩石非Darcy流渗透特性影响的试验研究

Experimental Study on the Influence of Confining Pressure over Non-Darcy Flow Permeability in Post-failure Rocks

研究围压对峰后岩石非Darcy流渗透特性的影响对峰后岩石非Darcy渗流系统的失稳具有十分重要的意义。本文基于岩石渗透试验装置与MTS815.02岩石力学伺服试验系统,研究给出了峰后砂泥岩、灰岩、砂岩在不同围压下的非Darcy流渗透特性。以上试验研究表明,峰后岩石非Darcy流渗透率随着围压的增大而下降,其关系可近似用指数函数拟合;而峰后岩石非Darcy流β因子的绝对值随围压的增大呈增大趋势,其关系可近似用对数函数拟合。

The research on the impact of confining pressure on the non-Darcy flow permeability in post-failure rocks plays a significant role in the instability of non-Darcy flow system in post-failure rocks. A patented device, combined with MTS815.02 Rock Mechanical System was used to make the measurement of non-Darcy flow per- meability under different confining pressures. The experimental principle and system of non-Darcy flow permea- bility in post-failure rocks were presented. The non-Darcy flow permeability characteristics in post-failure rocks of sand shale, limestone and sandstone were obtained with different confining pressure, The experimental data indi- cates that the permeability rate of non-Darcy flow decreases with the increasing of the confining pressure which could be fitted by exponential function, while the results show that the value of ~ factor of non-Darcy flow is neg- ative and its absolute value increases with the increasing of the confining pressure, which could be fitted by loga- rithmic function.