Mechanism of oil layer damage resulted from chemical flooding and their solutions

This paper discusses the mechanism of formation damage and solutions in respects of polymer flooding, alkaline waterflooding and surfactant flood, and introduces the trend of study of formation damage resulted from chemical flooding. Formation damages in polymer flooding are mainly caused by solubility of polymers, its compatibility with fluids and absorptive retention in oil layers. Therefore, polymer's solubility and compatibility should be improved and absorptive retention should be properly controlled. Formation damages in alkaline waterflooding are mainly resulted from swell and dispersion of clay and formation plugging due to precipitation of alkaline in combination with cations, therefore swell and scale preventions should be performed. Formation damages in surfactant flood are mainly caused by sulfonate precipitation, e-mulsion plugging, as well as enrichment of surfactant.