Concepedia

Abstract

In order to enhance the oil recovery after polymer flooding,the heterogeneous phase combination flooding system(HPCF) consisting of surfactant,polymer and preformed particle gel(PPG) was designed for the strong heterogeneity of reservoir and the widely distributed remaining oil.The dilative capacity,viscoelastic properties,filterability and migration in cores for a series of synthesized PPG,and the interactions between PPG and polymer and the influences of PPG plus polymer on IFT were investigated.The results showed that PPG was a kind of viscoelastic dilative particle in brine and could be migrated under injection pressure in cores.The effective HCFS used for high temperature and salinity reservoir and post polymer flooding reservoir was as 1000 mg/L PPG+1000 mg/L polymer+0.3% Shengli petroleum sulphonate+0.1%nonionic surfactant 1709.The enhanced oil recovery was 13.6%(OOIP) after polymer flooding when 0.3 pore volume HPCF fluid was injected at water cut of 98%.