Study On The Performance Variation Law Of Hydrophobically Associating Polymer ASP Compound System In Long Distance Migration After Polymer Flooding

HPAM that commonly used in the oil field is very sensitive to temperature and salinity so it cannot applied to high temperature and high salinity reservoirs well.HAWP is a new kind of polymer with temperature-resistant,salt-resistant and shear-resistant properties,it can increase viscosity efficiently with wider range of temperature and salinity.In order to study the change law of various performances of HAWP ASP compound system after polymer flooding during the long distance migration process in porous media,first of all,static performances like rheological behavior,shear resistance,heat resistance,salt resistance of the HAWP ASP compound system are evaluated.Then through the 30 m long physical sand-packed model oil displacement experiment in laboratory,the change laws of system viscosity,component concentration,oil-water interfacial tension and emulsifying effect are studied and compared with HPAM ASP compound system of relative performances.The change rules of dynamic performance in HAWP ASP compound system in long distance migaration,enhanced oil recovery effect and mechanism of HPAM ASP compound system after polymer flooding are analyzed comprehensively.Research has shown that the shear resistance,viscoelasticity and effect of reducing the interfacial tension of HAWP solution is not as good as that of HPAM polymer solution,but it has high efficiency of increasing viscosity,temperature resistance and salt tolerance,and it has no negative effect on reduction in oil-water interfacial tension.The loss of the viscosity and component concentration of HAWP ASP compound system is serious at the early stage of injection which is affected by adsorption,retention and dilution,the farther distance from the entrance,the lower the concentration and viscosity of the system.The ultra-low oil-water interfacial tension of the ASP system can be reached to 10-3mN/m at the 1/3 distance of the model.The emulsifying effect near wellbore area of model was not ideal,and better emulsion was formed at the middle of the model,and a large number of demulsification and coalescence emerged at the 2/3 distance of the model.The injection of ASP system can greatly increase the injection pressure,and the residual oil in the near wellbore zone can be easily started up.Final recovery of the ASP compound system in oil displacement experiment is 67.95%,and it is increased by 12.17% on the basis of polymer flooding.The use of HAWP can reduce the usage of polymer,and reduce the production cost greatly.The results of research have guiding significance for the optimization and design of ASP system on the field application.