二维非均匀多孔介质中不可压两相驱替的有限分析算法

为提高油藏数值模拟算法的计算效率,在求解单向稳态渗流的有限分析算法基础上,构建二维非均匀多孔介质中不可压两相渗流的有限分析算法.算法中,网格界面上的平均渗透率不是简单地取为相邻网格渗透率的调和平均值,而是通过奇点邻域解析解积分求得.相比于传统的数值算法,有限分析算法随着网格的加密,能够很快地收敛(仅需将原始网格细分至2×2或3×3),并且其计算精度和收敛性不依赖于介质的非均匀强度,从而计算效率得到提高.

Finite Analytic Numerical Method for Two-Phase Incompressible Flow in 2 D Heterogeneous Porous Media

A finite analytic numerical scheme is constructed for two-dimensional two-phase flow in heterogeneous porous media. Compared with traditional numerical methods, FAM makes convergence faster as refinement parameter increases, and accuracy is independent with heterogeneity. In contrast, as using traditional numerical schemes to simulate flow through a strong heterogeneous porous medium, refinement ratio for grid cell needs to increase dramatically to get an accurate result. Compared with the proposed scheme, traditional numerical scheme underestimates greatly breakthrough time under coarse grids. However, to get a saturation distribution with high resolution even employing the proposed scheme, relative fine grids are still needed. This is different from FAM for solving a single phase flow, where coarse grids provide rather accurate results.