experimentally investigated the dependence of coal permeability on effective stress and gas slippage under cyclic loading and discussed the relationship between permeability and effective stress.
Yuan, "The impact of effective stress and gas slippage on coal permeability under cyclic loading," Journal of Natural Gas Science and Engineering, vol.
By measuring pore size of the sample suite using gas slippage measurements, we show that the largest drops in ethane relative permeability take place in rocks with the smallest pores.
Pore size estimates from gas slippage measurements could also be made assuming pores have slot-shaped cross-sectional geometries .
At mean pore pressures less than 2.3 MPa, the decreases in permeability closely match the predicted permeability decreases due to gas slippage (Figure 7).
At higher pore pressures, all samples have lower permeability than what is predicted due to gas slippage, but the magnitude of the difference between measured permeability and predicted permeability varies within the sample suite; at 3.45 MPa mean pore pressure (the highest mean pore pressure measured), the difference between measured permeability and permeability predicted due to gas slippage ranges from 28 to 84 percent (Table 1, column 6).
The impetus for this work was a concern that finding the relation between limit pressure of eliminating gas slippage effect and pore structure parameters can help obtain the limit pressure of specific pore structure rock.
It has been observed experimentally that pore structure has influence on gas slippage. In Figure 8, limit pressure and mean pore throat radius have logarithmic relation.
Liu et al., "Research on the critical index of considering gas slippage effect," Journal of Wuhan Polytechnic University, vol.
In the first model, gas slippage is considered; we could find that the matching result is not good.
Yang, "Pore scale network modelling of gas slippage in tight porous media," Fluid Flow & Transport in Porous Media Mathematical and Numerical Treatment, vol.
Wang, "Experimental investigation on the coupled effect of effective stress and gas slippage on the permeability of shale," Scientific Reports, vol.