Karpyn Zuleima T, Piri Mohammad
Department of Energy and Mineral Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802-5000, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2007 Jul;76(1 Pt 2):016315. doi: 10.1103/PhysRevE.76.016315. Epub 2007 Jul 31.
This paper presents a two-dimensional pore-scale network model of a rough-walled fracture whose inner structure had been mapped using x-ray microtomography. The model consists of a rectangular lattice of conceptual pores and throats representing local aperture variations. It is a two-phase model that takes into account capillary, viscous, and gravity forces. Mapping of fluids and fracture topology was done at a voxel resolution of 0.027 x 0.027 x 0.032 mm(3) , which allowed the construction of realistic fracture representations for modeling purposes. This paper describes the necessary data conditioning for network modeling, a different approach to determine advancing and receding contact angles from direct x-ray microtomography scans, and the network model formulation and methods used in the determination of saturation, absolute and relative permeabilities, capillary pressures, and fluid distributions. Direct comparison of modeled results and experimental observations, for both drainage and imbibition processes, is presented in the companion paper [M. Piri and Z. T. Karpyn, following paper, Phys. Rev. E 76, 016316 (2007)].
本文提出了一种粗糙壁面裂隙的二维孔隙尺度网络模型，该裂隙的内部结构已通过X射线显微断层成像技术进行了测绘。该模型由代表局部孔径变化的概念性孔隙和喉道的矩形晶格组成。它是一个考虑了毛细管力、粘性力和重力的两相模型。流体和裂隙拓扑结构的测绘是在0.027×0.027×0.032 mm³的体素分辨率下完成的，这使得能够构建用于建模目的的真实裂隙表征。本文描述了网络建模所需的数据处理、一种从直接X射线显微断层成像扫描中确定前进和后退接触角的不同方法，以及用于确定饱和度、绝对渗透率和相对渗透率、毛细管压力和流体分布的网络模型公式和方法。在配套论文[M. Piri和Z. T. Karpyn，后续论文，《物理评论E》76，016316(2007)]中给出了排水和吸水过程的模拟结果与实验观测的直接比较。
