In unconventional reservoir rocks, pore anisotropy and gas high Knudsen number (Kn) effect are prominent, while gas slippage factor is a crucial parameter to evaluate their apparent permeability. To analyze the correlation of gas slippage factor with pore anisotropy of porous media and Kn, two-dimensional bundle models and anisotropic porous media with same characteristic length were skillfully constructed in this work. A multi-relaxation-time Lattice Boltzmann model combining diffusive reflection boundary condition and Bosanquet-type viscosity model was applied to simulate gas high-Kn flow (Kn = 0.05–0.53) in them. The results showed that Kn and pore-scale anisotropy jointly determine gas slippage factor of anisotropic porous media, which has nothing to do with porosity, specific surface area, and intrinsic permeability in nature. Pore-scale anisotropy leads to the distinct nonlinear changes of gas slippage factor with Kn. When pore-scale anisotropy factor is between 5.37 and 14.58, gas slippage factor of porous media is positively correlated with Kn. But as pore-scale anisotropy factor is in a range from 1.0 to 5.37, gas slippage factor decreases with an increase of Kn. In addition, gas slippage factor of porous media increases with an increase of pore-scale anisotropy as Kn is in a range of 0.18 to 0.53. This work further improves the understanding of gas slippage factor and gas high-Kn effect in anisotropic porous media.

在非常规储集岩中，孔隙各向异性和天然气的高努森数（K n）效应非常突出，而瓦斯滑移因子是评估其表观渗透率的关键参数。为了分析气滑系数与多孔介质和K n的孔隙各向异性的相关性，在此工作中，熟练地构造了具有相同特征长度的二维束模型和各向异性多孔介质。结合扩散反射边界条件和Bosanquet型粘度模型的多重弛豫时间格子Boltzmann模型被用来模拟其中的气体高K n流量（K n = 0.05-0.53）。结果表明，Kn和孔隙尺度各向异性共同决定了各向异性多孔介质的气滑系数，与孔隙率，比表面积和自然界的固有渗透率无关。孔隙尺度各向异性导致气体滑移因子随K n的明显非线性变化。当孔尺度各向异性因子在5.37和14.58之间时，多孔介质的气体滑移因子与K n正相关。但是，由于孔隙尺度各向异性因子在1.0到5.37之间，气体滑移因子随K n的增加而减小。另外，随着K的增加，多孔介质的气滑系数随孔隙尺度各向异性的增加而增加。n在0.18至0.53的范围内。这项工作进一步提高了对各向异性多孔介质中气体滑移因子和气体高K n效应的认识。