A Comprehensive Review of Smart Water Injection in Carbonate and Sandstone Reservoirs with a Special Focus at Carbonate Reservoirs in South of Iran

In recent years, research activities on smart water flooding in oil industry have been increased significantly. Smart water injection, by optimizing the ionic composition and salinity of the injected water, is a promising technique to increase oil recovery. Studies over the past two decades have shown the benefits of smart water flooding over other oil recovery methods. So far, several mechanisms have been proposed to describe the performance of smart water process in literature. However, due to the complex chemical and physical reactions, the contribution of each mechanism in increasing oil recovery factor has not been determined; therefore, it is difficult to predict the performance of reservoirs behavior under smart water flooding. In this paper, smart water injection in carbonate and sandstone reservoirs has been comprehensively investigated. This study includes a review of effective mechanisms, laboratory and field observation and the challenge of smart water flooding in both carbonate and sandstone reservoirs. Finally, the screening criteria of candidate reservoirs for smart water injection are presented and based on that, smart water injection in carbonate reservoirs in southwestern Iran has been assessed.