Two-phase flow in correlated pore-throat random porous media

• 来源期刊: 中国物理（英文版）
• 学科: 物理学
• 关键词: correlation parameter fractal dimension sweep efficiency scaling function
• 年，卷（期）: 2002,（4）
• 页码范围: 358-365
• 页数: 8页
• 分类号: O4
• 语种: 英文

摘要

We have constructed a porous media model in which there are percolation clusters with varying percolation probability P and correlated site-bonds. Taking into account both the pore and the throat geometry, the viscous fingering (VF) in porous media has been investigated by using the standard over-relaxed Gauss-Seidel scheme. The simulation results show that the VF structure varies with the correlation parameter ε, the viscosity ratio M and the percolation probability P. The smaller the correlation parameter ε, the greater thedeviation of the normalized size distribution of the invaded throat Ninv(r) from the truncated Rayleigh distribution.For a larger viscosity ratio M,the VF pattern looks like a diffusion-limited-aggregation structure in percolation clusters. The fractal dimension D increases with the increase of the percolation probability P and the correlation parameter e. The velocity distribution f(α) of VF in percolation clusters is of a parabola-like curve. The tail of the distribution (large α) is longer for a larger correlation parameter ε. For a smaller ε, the distribution is very sharp. The sweep efficiency E decreases along with the decrease of the correlation parameter ε and the increase of the network size Lnz. E has a minimum as Lnz increases up to the maximum no matter what the values of P, M and ε. The E ～ Lnz curve has a frozen zone and an active zone. The geometry and the topology of the porous media have strong effects on the displacement processes and the structure of VF.