| Surfactant oil displacement is an important technique in Enhanced Oil Recovery(EOR). According to the actual reservoir conditions, the surfactant with high oil displacement efficiency and low cost is a prerequisite condition for practical application.There are few oil displacement agents for reservoirs with high salinity and low permeability. In this paper, in order to find the surfactants with high salt tolerance and low interfacial tension, three series of surfactants were synthesized, two of which belong to zwitterionic surfactants, while another one cationic gemini surfactants with ten different types. The surfactants were characterized by elemental analysis, infrared spectrum and ESI-Mass spectrometry.According to the requirements of surfactants used in enhanced oil recovery technology, physico-chemical properties including surface tension, critical micelle concentration (cmc), contact angle, oil-water interfacial tension, compatibility with formation water were fully studied. Under the condition of solution salinity 65430 mg/L, the two series of zwitterionic surfactants were all transparent and cationic gemini surfactants LZ-1?LZ-3 were also transparent. Cationic gemini surfactant LZ-3 could reduce the interfacial tension to 10-3 mN/m order.The salt tolerance, adsorbability, formulation experiment and flooding experiment of cationic gemini surfactant LZ-3 were also measured. Under the condition of 50? and 0.1% concentration,LZ-3 solution could keep transparent with 80 g/L salinity. The ? of LZ-3 was 6.3?11.5 mg/g. In formulation experiment, the oil-water interfacial was changed without significant decrease. Gemini surfactant LZ-3 could improve the oil displacement efficiency by 11.09%. |
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