Effects of Salt on Interfacial Tension of Surfactant-Brine-Oil System

The concept of interfacial tension is very important surfactant flooding under the field of chemical enhanced oil recovery. Using the spinning drop tensiometer, this work aims to determine the interfacial tension between the mixture of brine with surfactant and oil, using different salts at different concentrations and temperatures. It is found that the oil-brine interfacial tension increases with decreasing salt concentration, increasing temperature, and use of NaCl instead of MgCl2; while it decreases with use of surfactant and decreases further with use of surfactant added with salt.