Gas permeability calculation of tight rocks based on laboratory measurements with non-ideal gas slippage and poroelastic effects considered

摘要: Abstract Permeability measurements on low-permeable rocks in the laboratory require much higher pressure gradients than those real reservoirs to produce detectable flow rates finite time. This may result a high effective stress gradient that can cause non-uniform deformation of pore system. To better understand measured data, theoretical model has been developed for calculating gas permeability tight rock from measurements, which couples effect poroelastic with non-ideality and slippage effects. The proposed characteristic considers effects calculation, improves accuracy calculated under large gradients. new is validated by independent multiscale simulations, are captured scale while behavior core scale. numerical results also indicate mainly affects high-pressure region variation properties dominates low-pressure region. then applied calculation based coal shale samples non-ideal considered. be important as well apparent will overestimated if these two neglected.