Li Ruru, Yang Y Sam, Pan Jinxiao, Pereira Gerald G, Taylor John A, Clennell Ben, Zou Caineng
North University of China, School of Information & Communication Engineering, Xueyuan Road 3, Taiyuan, Shanxi Province 030051, China.
CSIRO, Private Bag 33, Clayton, Vic 3169, Australia.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Sep;90(3):033301. doi: 10.1103/PhysRevE.90.033301. Epub 2014 Sep 2.
A partial-bounce-back lattice Boltzmann model has been used to simulate flow on a lattice consisting of cubic voxels with a locally varying effective percolating fraction. The effective percolating fraction of a voxel is the total response to the partial-bounce-back techniques for porous media flow due to subvoxel fine structures. The model has been verified against known analytic solutions on two- and three-dimensional regular geometries, and has been applied to simulate flow and permeabilities of two real-world rock samples. This enables quantitative determination of permeability for problems where voxels cannot be adequately segmented as discrete compositions. The voxel compositions are represented as volume fractions of various material phases and void. The numerical results have shown that, for the tight-sandstone sample, the bulk permeability is sensitive to the effective percolating fraction of calcite. That is, the subvoxel flow paths in the calcite phase are important for bulk permeability. On the other hand, flow in the calcite phase in the sandstone sample makes an insignificant contribution to the bulk permeability. The calculated permeability value for the sandstone sample is up to two orders of magnitude greater than the tight sandstone. This model is generic and could be applied to other oil and gas reservoir media or to material samples.
一种部分反弹晶格玻尔兹曼模型已被用于模拟在由具有局部变化有效渗流分数的立方体素组成的晶格上的流动。体素的有效渗流分数是由于亚体素精细结构而对多孔介质流动的部分反弹技术的总响应。该模型已针对二维和三维规则几何形状上的已知解析解进行了验证，并已应用于模拟两个实际岩石样品的流动和渗透率。这使得能够对体素不能作为离散成分进行充分分割的问题进行渗透率的定量测定。体素组成表示为各种材料相和孔隙的体积分数。数值结果表明，对于致密砂岩样品，总体渗透率对方解石的有效渗流分数敏感。也就是说，方解石相中的亚体素流动路径对总体渗透率很重要。另一方面，砂岩样品中方解石相中的流动对总体渗透率的贡献微不足道。砂岩样品的计算渗透率值比致密砂岩高出两个数量级。该模型具有通用性，可应用于其他油气储层介质或材料样品。
