A new method to reconstruct structured mesh model from micro-computed tomography images of porous media and its application

Pore-scale modeling of porous media has been emphasized as a platform to study the mechanical properties, fluid storage and transport properties in it. A universal and easy-to-realize approach of structured mesh model is presented in this paper to reconstruct the three-dimensional (3D) pore scale models from the micro computed tomography (micro-CT) images. By substituting the structured hexahedron elements for the voxels in the 3D images, codes are developed to reconstruct the micro structure of porous media. The structured model is tested by the micro-CT images of four rock samples. The advantages of topology and mesh quality of this model is validated by comparisons between the PNM and unstructured mesh models. Then numerical simulations of single- and two- phase flow are conducted in Fluent software. The models are validated between the experimental data and simulation results of PNM on the absolute permeability and relative permeability curves under different conditions of sample wettability.