Oil components in Smart water processes

Due to its potential as an economical and simple method of increasing oil recovery, there has been an increasing interest in low salinity water flooding. A significant number of coreflooding studies and field trials have confirmed that oil recovery can be improved by injecting water with a salinity less than 5000ppm. Different hypotheses regarding the underlying mechanism for low salinity waterflooding have been proposed by various researchers, but contradictory results can be found for each of these mechanisms. However, researchers agree that additional oil recovery by low salinity water can be attributed to wettability alteration. This study aims to highlight the importance of brine composition, rock mineralogy and oil composition on rock wettability. For this purpose, modified flotation tests were carried out with different crude oil/brine/rock systems. As clay minerals have been reported to be decisive for observing increased oil recovery by low salinity water in sandstones, two of the selected minerals are clay minerals. Polar compounds as well as acid and base ratio of crude oil are believed to play a crucial role in altering rock wettability. Hence, besides synthetic oil, stock tank oil was used to study the impact of polar compounds. The influence of acidity and basicity of oil were investigated by adding acid and bases to the system. Beyond this, the most important interactions between crude oil and the solid surface have been identified and discussed thoroughly.