针对气体在致密多孔介质中低速渗流时,其渗流规律在渗流曲线的低压段表现出对达西定律线性关系的偏离,存在着非达西现象。采用格子Boltzmann方法,研究气体和多孔介质的特性对气体渗流Klinkenberg效应的影响因素。结果表明:在气体渗流曲线的低压力梯度段,随着气体黏度系数、净围压、渗透率和孔隙率的变小,渗流曲线的非线性临界点向压力梯度增大的方向移动,对达西定律线性关系的偏离更明显。说明在低渗和低压情况下Klinkenberg效应不能被忽略,气体黏度系数和孔隙率对Klinkenberg效应作用有影响;当净围压或渗透率很大时,气体渗流流量和压力梯度符合达西定律线性关系。
The characteristics of gas flow at low velocity in a tight porous media deviate from the linear relationship of Darcy law within low pressure section,which is called non-Darcy phenomena.The impact of gas and the porous media characteristics on gas flow Klinkenberg effect is investigated in this study using lattice Boltzmann method.The results show that at the low pressure gradient,with the decreases of gas viscosity,net confining pressure,permeability and porosity,the nonlinear critical point moves toward the direction of pressure gradient increase.The deviation from Darcy phenomena linear relationship is even significant.It proves that Klinkenberg effect cannot be neglected under the conditions of low permeability and low pressure.In particular there are some impact on Klinkenberg effect from gas viscosity and porosity.The relationship between gas seepage flow rate and pressure gradient is in line with Darcy phenomena when net confining pressure or permeability is high.