Study Of Heterogeneous Combination Flooding System Based On The Dispersed Particle Gel

The heterogeneity of the reservoir became strong and the remaining oil distributed universally after polymer flooding,meanwhile the existing chemical compound flooding systems had limited application problems,the heterogeneous combination flooding system based on dispersed particle gel are developed for enhancing oil recovery after polymer flooding.In this paper,the design and characterization of heterogeneous combination flooding systems was carried out,and the application performance and flooding mechanism was analyzed.Based on the viscosity and interfacial tension for determining,the flooding system is optimized,and the appropriate ingredient of the combination flooding system is that the mass concentration of 300⁶00mg/L THSB surfactant,the SDYF polymer is 1000²000mg/L,and the dispersed particle gel is 1000³000mg/L.The viscosity of the flooding system is 12.1¹7.3mPa·s,the oil-water.interfacial tension maintains at 10^-3mN/m.The temperature and salinity resistance property of the flooding system is good,the retention rate of viscosity was more than 83.5% and the oil-water interfacial tension still reached 10^-3mN/m after aging 60 days at 80?.Because of the competition adsorption between the polymer and surfactant,the adsorption of the system is less compared with the single flooding system of polymer or surfactant.The application performance are studied by physical simulation experiment,showing that the heterogeneous combination flooding system has a good injectivity and a good plugging capability in the course of migration,with the performance of plugging the high permeability layer while not the low permeability layer.The heterogeneous combination flooding system could migrate to the deep formation and enhance the oil recovery by 19.35% after polymer flooding.The study of visual simulation experiments on the mechanism of flooding show that the heterogeneous combination flooding system has the best profile control property after polymer flooding.The profile control and oil displacement function of the heterogeneous flooding system is mainly depended on the increasement of viscosity by polymer,the plugging performance of dispersed particle gel,the film solubilization of surfactant,the emulsification of surfactant,the drag brushed effect,the pulling of the polymer and extrusion of the dispersed particl gel.