The Study Of Numerical Model For Aging Of Polymer Flooding

Polymer flooding technology is the way to drive out oil by injecting poly-mer solution into the formation,which has been widely used in chemical flood-ing technology of tertiary oil recovery.The viscosity of polymer solution is particularly important for polymer flooding.Polymer aging refers to the phe-nomenon that the polymer is affected by physical or chemical factors,with constant concentration and reduced viscosity,so it is not perfect to simply use concentration to characterize viscosity.Moreover,it is dificult to characterize the process of aging and flowing of polymer,because the polymer solution is mobile,and there is a process of new old alternation in the fixed area.The main content of this paper is:the flow of polymer solution in porous media under incompressible and miscible conditions is single-phase and multi-component,and the whole convection diffusion process is dominated by con-vection.Based on the pressure equation,concentration equation and modified polymer aging equation,the mathematical model of polymer aging degradation under reservoir conditions is established.The characteristic difference method is used to solve the model,and the error estimation is given.The model is as follows:and give the characteristic difference scheme.It is testified that the scheme has a convergence rate of O(h)in the space of l2(?)using piecewise bilinear inter-polation,and a convergence rate of O(h2)using local quadratic interpolation,which provide theoretical support for the study of numerical model of poly-mer displacement aging.In this model,viscosity,as an independent variate,is no longer affected by the concentration,and directly affects the permeability through viscosity,which is more consistent with the physical fact that the con-centration of polymer is constant dduring the aging process and the viscosity is reduced.Through numerical simulation,polymer flooding improves the oil recovery from 31%to 55%.Due to the influence of polymer aging,the final recovery is significantly lower than that of conventional simulation(polymer without aging).The influence of polymer aging on oil recovery can not be ignored.Numerical simulation technology provides reference for polymer ma-terial research and development as well as oil field production and development program.In this paper,the coupling system is established,the difference scheme is given and the convergence is analyzed.And the numerical simulation is carried out..The paper is divided into four chapters:Chapter 1:The background of the three equations in the coupled system the research status at home and abroad and the model knowledge are intro-duced.Chapter 2:The characteristic difference scheme of the system is given and its convergence is analyzed.Chapter 3:The numerical simulation of polymer aging was carried out.Chapter 4:A summary and outlook of this paper are given.