3D numerical reconstruction of well-connected porous structure of rock using fractal algorithms

Natural rock, such as sandstone, has a large number of discontinuous, multi-scale, geometry-irregular pores, forming a complex porous structure. This porous structure essentially determines the rock’s physical and/or mechanical properties, which are of great significance to a variety of applications in the fields of science and engineering. As a supplement to experimental observation, a reliable reconstruction model of porous structure could provide an effective and economical way to characterize the physical and mechanical properties of a porous rock. In this paper, we present a novel method for reconstructing the well-connected porous structure of sandstones, which are often intractable to handle for current reconstruction methods. A fractal descriptor is here proposed for better characterizing complex pore morphologies. The reconstruction procedure of a 3D well-connected porous structure is optimized by integrating the improved simulated annealing algorithm and the fractal system control function. The proposed reconstruction method enables us to represent a large-size 3D porous structure. To verify the accuracy of reconstruction, we have analyzed the geometrical, topological, and mechanical properties of the reconstructed porous medium and compared them with those of prototype rock samples. The comparisons show good agreement between the reconstructed model and the real porous sandstone.