Review on Low Salinity Injection in Carbonated Reservoirs and Challenges

The water injection process and flooding for many years as one of the most important practical methods to maintain reservoir pressure and improve the flow of oil to the production wells are known. The results of the studies show that the rock composition and salinity water injection have a significant impact on flooding process efficiency. Low salinity water injection because of the availability of water and its compatibility with the environment and cheaper than other methods of injection is practical. The experimental results showed that the highest oil recovery is achieved when the concentration of salt in water injection is less than the formation water. Several mechanisms to describe the low salinity water injection for enhanced oil recovery. As stated that the migration of clay particles, changing the wettability, ion exchange, expansion of the dual-layer, changing PH, dissolved minerals, and salt effect. Interactions and interactions between mechanisms have added the complexity of understanding the exact efficiency of low salinity water injection. Although it is generally believed that low salinity water injection causes enhanced oil recovery factor, but because of inconsistencies in the results of some tests there were doubts in this regard. In addition to the low salinity water injection will be referred challenge for association studies.