A Study On The Flow Characteristics Of Particles In Porous Media

The geological structure of the rock's reservoir is porous,reservoir space is the place where oil and gas occur,but also the flow of fluid channels.,The porosity of the reservoir rock is defined as the gap between the particles in the rock,within the particles and in the interstitial matter,,Porosity determines the amount of stored fluid.So,the study of porous media in rock reservoir is of great significance to petroleum engineering.Based on oil and sand in porous media of petroleum reservoir,the particles flow characteristics in porous media were simulated from microscopic scale.In this paper,DEM-CFD method was used to simulate the liquid and particle phase in porous media.The Euler method is used to study the liquid flow,and the particle phase is regarded as a discrete phase.The Gidaspow drag model is used to consider the interphase interaction.In order to consider the phenomenon of deformation caused by intermolecular collision,The softball model is used to simulate particles.In the physical model,a simple straight porous media model and a branched porous media model were established.The effects of porosity,liquid viscosity,liquid velocity,sand density and oil sands ratio on the flow in porous media were studied.Compare and analyze the results,get the law of movement of liquid and particles.The simulation results show that the liquid has a great effect on the movement of the oil particles during the movement of the particles in the porous media,which have small density and large particle size.The larger the porosity of the porous medium,the larger the space of the particles moving in the porous medium,and the longer the residence time of the particles.Increasing the viscosity of the liquid will hinder the movement of the particles and affects the degree of dispersion of the particles in the porous medium.The larger the density difference of the two kinds of particles,the stronger the rotation of the particles in the porous medium.The ratio of oil and sands will affect the particle movement in the porous medium.When the oil-sands ratio is 1:2,the velocity of the particles is the fastest,and when the oil-sands ratio is 1:3,the particles move slowly and the sand particles are easy to deposited at the bottom of the porous medium.In the study of branched porous media model,The branch channel has a significant effect on the shunting of the particles.In the lower branch channel,the number of particles is large and the speed is fast,in the upper branch channel,the number of particles is small and the movement is slow,and some sand particles appear reflux phenomenon.The greater the porosity,the greater the degree of dispersion of the particles and the longer the residence time of the particles.The viscosity of the liquid can change the particle distribution,When the liquid viscosity is large,the particles are symmetrically distributed.The increase in viscosity will hinder the movement of the particles to a certain extent,the pulsation of the particle is weakened,and the granular temperature is reduced.The greater the speed of the inlet,the greater the rotational motion of the particles in the main channel,and the number of particles in the lower branch channel will significant increase.The proportion of oil and sands will affect the rotation of the particles,Compared with the oil-sands ratio of 1:2 and the oil-sands ratio of 2:1,it is found that the particles will show the opposite rotational motion in the main channel;In one model,the direction of the particles in the adjacent rotation zone is opposite.