Study on oil-water interfacial tension of anionic gemini surfactant

In order to probe the oil-water interfacial activity and feasibility of enhancing oil recovery by a new-type Anionic Gemini surfactant (GA series). The experiment was conducted under the circumstance of simulated formation water and Donghetang thin oil at the temperature of 45 ℃. Interfacial tension between Anionic Gemini surfactant with different structures and thin oil were tested through “rotating drop method”. By taking GA12-4-12 as an object, its dynamic interfacial tension in different concentrations was recorded. Also, the blending performance with nonionic surfactant ANT was explored. Results showed that the longer length of linking group is and carbon chain, the lower is interfacial tension between Gemini surfactants solution and oil. As GA12-4-12 concentration increased, the interfacial tension first decreased to a certain point and then increased. Water-oil interfacial tension of 0.3% of GA12-4-12 was only 0.00885 mN/m while the time stability got worse. The synergetic efficiency of GA12-4-12 /ANT mixed system was obvious. When ratio came to 4∶1, concentration of (GA12-4-12+ANT) was 0.1% and water-oil interfacial tension dropped to ultralow (0.00884 mN/m), which obviously reduced the amount of GA12-4-12. It can be seen that GA12-4-12 /ANT mixed system has the possibility to enhance oil recovery in a low amount. It is recommended to make experimental research on water flooding recovery of this formula.