Simulation of the Erosion Process in Porous Media Based on Particle-Seepage Coupling

In response to the migration, deposition, and blockage of particles in porous media, this paper explores the microscopic mechanisms of fine particle migration and deposition based on the particle - seepage coupling coupled numerical method. PFC3D is used to construct porous media samples, and a flow program is written in Python to achieve bidirectional coupling between particles and fluids. This article derives the governing equations for particles and fluid phases in a saturated state, and verifies the mechanical parameters of the microscale model by comparing microfluidic experimental data. Using the JKR contact model to consider the gravitational interaction between fine particles, a numerical simulation was conducted on a cylindrical porous medium model. The results showed that considering the interaction between particles, there was a large agglomeration in the pores of the model, and fine particles were easily adsorbed on the surface of the porous medium, making the model more prone to blockage. Additionally, a particle stacking arch structure appeared in the pores of the porous medium; In addition, considering the influence of the type of JKR contact bond formed on the permeability changes within the interparticle interaction model, and the permeability curve eventually tends towards a flat stage; Finally,the internal particle mass distribution within the model exhibits spatial heterogeneity. The middle layer region (L2) of the model forms a blocking layer, while the bottom region (L3) demonstrates steady-state clogging when considering particle interactions. In contrast, models disregarding particle interactions manifest dynamic immigration/emigration equilibrium.