Low Salinity Water flooding and Combination of Low Salinity Water flooding with Surfactant and Alkaline Injection to Improve Oil Recovery - Core Flooding Experiments

Several laboratory and field tests indicated that oil recovery in water flooding is dependent on the chemistry and salinity of the injected water,and that low salinity water injection can improve oil recovery. Low salinitywater is a promising method for improving oil recovery in sandstonereservoirs. Several mechanisms have known to be responsible forimproving recovery by low salinity water flooding; though the predominant mechanism has not truly been known. This paper presents laboratory results and analysis of core flood studies of an Iranian oil reservoir for understanding how the water and oil chemistryand temperature affects the final recovery in order to optimize low salinity water flooding process. Experiments was done in tertiary recovery mode,first injection of formation water and then injection of low salinity water or combination of low salinity water and chemicals like surfactant or alkaline.The results showed improving effect between ٤-٢٢% in tertiary oil recovery. It concludes that combination of low salinity water with surfactant oralkaline is drastic method for boosting the effect of low salinity water flooding. Also it deduces that decreasing the water salinity, increasingtemperature and present of divalent ions in low salinity water can boost improving effect of low salinity water flooding.