A Study on Particle Suspension Flow and Permeability Impairment in Porous Media Using LBM-DEM-IMB Simulation Method

The paper studies the particle retention and permeability impairment in porous media. This problem results from the re-injection of produced groundwater during oil production into the oilfields in order to reduce environmental damage. The lattice Boltzmann method (LBM) is used to simulate the fluid flow. The discrete element method (DEM) is adopted to simulate the particle motion. The fluid-solid interactions are simulated using the immersed moving boundary method (IMB). Based on the coupling LBM-DEM-IMB method, the paper studies the effect of particle diameter, flow rate, particle volume fraction and injection amount on the particle retention and permeability impairment. Results indicate that larger particle diameter, lower flow rate, higher volume fraction and more particle injection lead to more severe permeability impairment. In order to further study the effect of particle suspensions on heterogeneous reservoirs, a two-channel model with different permeabilities is established. The simulations show that smaller particles tend to retain in the low permeable channel and its permeability impairment is more severe. On the contrary, larger particles can reduce the permeability of high permeable channel, but they can protect the permeability of low permeable channel due to the mechanism of membrane filtration. Therefore, the sweep efficiency and oil recovery of the heterogeneous reservoirs can be improved by re-injecting produced groundwater after reasonable pretreatment. The re-injection also reduces environmental damage resulting from the large amounts of produced water in petroleum engineering. This paper provides some references for general studies on the flow of particle suspension in porous media.