Bakhshian Sahar, Hosseini Seyyed A, Shokri Nima
Bureau of Economic Geology, Jackson School of Geosciences, The University of Texas at Austin, Austin, TX, 78758, USA.
School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester, UK.
Sci Rep. 2019 Mar 4;9(1):3377. doi: 10.1038/s41598-019-39741-x.
This study provides a pore-scale investigation of two-phase flow dynamics during primary drainage in a realistic heterogeneous rock sample. Using the lattice Boltzmann (LB) method, a series of three-dimensional (3D) immiscible displacement simulations are conducted and three typical flow patterns are identified and mapped on the capillary number (Ca)-viscosity ratio(M) phase diagram. We then investigate the effect of the viscosity ratio and capillary number on fluid saturation patterns and displacement stability in Tuscaloosa sandstone, which is taken from the Cranfield site. The dependence of the evolution of saturation, location of the displacement front, 3D displacement patterns and length of the center of mass of the invading fluid on the viscosity ratio and capillary number have been delineated. To gain a quantitative insight into the characteristics of the invasion morphology in 3D porous media, the fractal dimension D of the non-wetting phase displacement patterns during drainage has been computed for various viscosity ratios and capillary numbers. The logarithmic dependence of D on invading phase saturation appears to be the same for various capillary numbers and viscosity ratios and follows a universal relation.
本研究对实际非均质岩石样品一次排水过程中的两相流动动力学进行了孔隙尺度研究。采用格子玻尔兹曼（LB）方法，进行了一系列三维（3D）不混溶驱替模拟，识别出三种典型流动模式，并绘制在毛细管数（Ca）-粘度比（M）相图上。然后，我们研究了粘度比和毛细管数对取自克兰菲尔德场地的塔斯卡卢萨砂岩中流体饱和度模式和驱替稳定性的影响。已描绘出饱和度演化、驱替前沿位置、三维驱替模式以及侵入流体质心长度对粘度比和毛细管数的依赖性。为了定量洞察三维多孔介质中侵入形态的特征，针对不同的粘度比和毛细管数，计算了排水过程中非润湿相驱替模式的分形维数D。对于不同的毛细管数和粘度比，D对侵入相饱和度的对数依赖性似乎相同，并遵循一个通用关系。
