Digital Simulation Of Flow Field Of Residual Oil Droplets In Microporous Channels Displaced By Viscoelastic Fluid

The production practices and indoor oil flooding test results of various oilfields at home and abroad have shown that the use of polymer solution with viscoelastic properties after water flooding is an effective method to improve oil recovery.However,this type of viscoelasticity The hydrodynamic mechanism of the displacement fluid to improve oil recovery needs to be improved.In order to further explore the hydrodynamic mechanism of the viscoelastic displacement fluid to displace the residual oil film in the micro-scale pores of the underground oil layer,promote the development of non-Newtonian fluid mechanics.Maxwell's co-rotation constitutive equation is used to describe the viscoelastic polymer solution,and the two-dimensional and three-dimensional flow equations of the viscoelastic fluid in the micro-scale flow channel are established.The Polywell co-transformation constitutive equation is introduced in Polydata.The user-defined function(UDF)makes it more suitable for numerical simulation of the flow of viscoelastic displacement fluid.The flow field is calculated and analyzed by numerical method,and the pressure of the corresponding viscoelastic displacement fluid to displace the micro residual oil flow is obtained.Distribution,velocity distribution and stress distribution;the tensor theory was used to calculate the stress of the residual oil film on the residual oil film,and the level of polymer flooding compared with water flooding was proposed.The increase of force is one of the important reasons for improving the efficiency of oil displacement.The variation law of the horizontal stress difference with the Wesenberger number We reflecting the elastic effect is given.The deformation of the residual oil film is calculated by the interface theory.The "deformation index" is used to analyze the influence of Weissenberg number on the deformation of residual oil film.The distribution of the number of capillary tubes after residual oil film deformation on the surface of residual oil film is calculated.The "critical capillary number" for judging the residual oil film rupture is proposed.The migration law of residual oil film was discussed.The calculation results show that the higher the concentration of the polymer solution,the greater the elasticity of the displacement fluid,the larger the normal deviator stress,the greater the horizontal stress difference,the more obvious the deformation of the residual oil,and the elasticity of the displacement fluid is to improve the drive.An important reason for oil efficiency.