Study Of Flow Characteristics Of Suspended Particles In Porous Media Based On LBM-DEM

Most oilfields in China have entered a period of high water cut,and the produced water is often reinjected in the production process.In practice,problems such as the increase of injection pressure and the decrease of fluid flow rate will be encountered,which are caused by impurities in the reinjected water.The deposition of sand particles caused by water flooding,the deposition of gel particles and microorganisms caused by chemical flooding and microbial flooding will lead to a decrease in permeability of reservoirs.Therefore,it is of great significance to grasp the movement law of particles in porous media in particle suspension to improve the development performance of petroleum.In this study,the flow process of suspended particles in porous media is simulated by LBM-DEM.The liquid phase is solved by Lattice Boltzmann Method(LBM),and the granular phase is calculated by Discrete Element Method(DEM),and the coupling effect between the two phases is considered.A three-dimensional model of porous media is established to study the influence of flow characteristics in porous media under different porosity,fluid viscosity,flow velocity,particle size and quantity etc.The trajectory,deposition position,escape rate and granular temperature of suspended particles in porous media are simulated.The simulation results show that with the increase of fluid viscosity,the average velocity of particles increases,the escape rate of particles increases,the increase range of escape rate slows down,the pulsation of the instantaneous axial velocity of particles decreases,and the location of deposited particles changes little.Some of the particles are located at the entrance of porous media,while others are evenly distributed along the direction of fluid flow in porous media.With the increase of fluid velocity,the average velocity of particles increases,the escape of particles increases first and then decreases,the pulsation of the instantaneous axial velocity of particles increases,and the number distribution of deposited particles decreases along the direction of fluid flow.With the increase of porosity of porous media,the average velocity of particles increases,the escape rate of particles increases,the pulsation and frequency of instantaneous axial velocity of particles decrease,and the quantity distribution of deposited particles tends to be average gradually along the direction of fluid flow.With the increase of particle size,the average velocity of particle motion decreases,the escape rate of particle decreases,and the granular temperature of particles decreases linearly.With the increase of the number of particles,the change of the average velocity of particles is not obvious,which is consistent with the experimental results,the escape rate of particles decreases,while the granular temperature of particles increases.