Research on Numerical Simulation of Gas Flow in Shale Matrix Micro Pore

摘要

In view of Longmaxi shale core in Sichuan basin, two-dimensional images of shale core were given by using scanning electron microscopy (SEM), and processed by ImageJ software to reconstruct the 3D shale matrix digital core, the digital core can reflect the nano pore structure more accurately. LBM model of gas flow in shale porous medium is established based on lattice Boltzmann method. The corresponding boundary conditions were established based on slip phenomenon for shale gas in porous medium micro flow, which can simulate gas flow in the micro pore in shale more realistic. The numerical results show that the microscale effect becomes obvious with the increase of Knudsen number, and the more obvious the non-Darcy phenomenon of gas flow in the shale matrix. The research results of this paper provide a theoretical basis for shale matrix permeability calculation, shale gas well productivity evaluation and development scheme design.