Numerical Simulation Of Flow Behavior Of Particles In A Porous Media

The movements of particles in a porous media exist in various modules of oil field development and production.The existence of solid fine particles influence oil velocity and free path,such as clay minerals,sandstones and quartz,with the change porosity of the microchannel altered by fine particle deposition,therefore an irreversible and permanent impairment of reservoir porosity and permeability are caused.It is hard to get standardized experimental results because of the diversity of porous media.Therefore,the migration of fine particles in anisotropic porous media is analyzed under the microscale condition in this study.The CFD-DEM approach and Kinetic Theory of Granular Flow(KTGF)are used to simulate the flow behavior of particles in a three-dimensional anisotropic porous media.The Euler and Lagrange methods are used to solve the flow field of continuous phase and the particle field of discrete phase,respectively.Huilin-Gidaspow model is used to solve the interphase between fluid and particle.The effects of porosities of porous media,pore structures,particle size,fluid viscosity and initial velocity of fluid on the charicteristics of particle migration and deposition are studied,which provides theoretical support for the development of liquid-solid two-phase flow in the pore and the development and application of actual reservoirs.The numerical simulation results show that particles will be blocked and resident in the porous media at a relatively low porosity.Increasing porosity prolongs the trajectory of particles,and particles do reciprocating motion and flow out the microchannel.Simulated results indicate that with an increase of porosity,the residence time and granular temperature are decreased,and then increased.The contact force between particles and the instantaneous axial/radial velocity of particles decrease with the increase of porosity,while the axial velocity is greater than the radial velocity.The velocity of fluid decreases along the axial position of micro-channel.The oblate ellipsoid particles which fixed randomly in the microfracture prolong the residence time and of particles and increase the fraction of trapped particles.With the increase of aspect ratio,the fluctuation frequency increases,while the instantaneous velocity,contact force and granular temperature of particles decrease.The deposition of particles occur with the increase of particle size,the same as the effect on the residence time and fraction of trapped particles.While the fluctuating velocity of particles decreases,the contact force,instantaneous axial,radial velocity and granular temperature of particles decrease with the increase of particle size.The predicted axial velocity of particles and the granular temperature decrease with an increase of liquid viscosity,while the mean residence time and contact force increase with an increase of liquid viscosity.Simulations indicate that the granular temperature and the contact force are increased,and the residence time and the fraction of trapped grains is reduced with an increase of liquid velocity.