Stress And Deformation Analysis Of Residual Oil Droplets In The Micro Pores

Polymer flooding is a complicated problem,which analyzed can improve oil recovery and get great economic benefit. In recent years, the technology has developed rapidly, oil production of polymer flooding wells has possessed certain proportion in Daqing oilfield. The residual oil film distributed in different forms with its cohesion,adhesion of rock to the residual oil,interface free energy between oil film and driving fluid. Rely on visoelasticity the Polymer flooding can improve oil recovery. According to the existence of residual oil film of oil polar rock after the polymer flooding and viscoelasticity of polymer solution, adopting common conversion Oldroyd-Maxwell constructive equation, in this paper, the flow physical model of viscoelastic fluid in the micro-pore was established, and was calculated with the Polyflow, the stress and deformation analysis of residual oil droplets were analyzed, the force of different interfacial tension of residual oil displacement fluid were researched, elastic and unelastic displacement effect on residual oil liquid in the micro force were calculated. By using the result simulated, analyzing the influence of elastic behavior to micro force, calculating deformation of residual oil film. The result shows that unelastic displacement solution is hardly able to make oil droplets deformation; the normal stress which the elastic displacement solution produce can make oil droplets larger deformation and let oil droplets produced a prominent part of the rear in the oil droplets after deformation; in the same pressure gradient situation, the larger deformation of the oil film with increase in elastic behavior of fluid, and the micro force of the rear also change. When oil film become deformed to a certain extent will burst (isolated droplets). It can be inferred that the viscoelastic fluid displacement effect on oil film can separate more oil droplets from oil film, forming a free droplets and drived for displacement solution, which can improve the displacement efficiency.