Study On Properties Of Sulfobetaine-type Fluorocarbon Surfactant

Fluorocarbon surfactant is the highest of the special surface active surfactant, which makethem have a good prospect in EOR area. In this paper, sulfobetaine-type Fluorocarbonsurfactant FS was synthesized, and its performance were studied, we first studied the foam ofthe complex systems(sulfobetaine type of fluorocarbon surfactant FS and anionic surfactantAOS), the best determined complex system is FS:AOS=1:5(0.2wt%). The influence ofalcohols, polymers, pH, temperature, kerosene on foam performance of the mixed systemFS/AOS were studied and results show that the mixed system FS/AOS have better foamperformance, chemical stability, salt resistance and oil resistance. Short-chain alcohols, xyloseand fructose could improve the complex system FS/AOS foaming capacity, and long-chainalcohols and polyols were not well improve their foaming capacity, the effect ofpolyacrylamide HPAM on improving the foam stabilizing ability of the FS/AOS was moreobvious than the polyvinylpyrrolidone PVP and Hydroxyethyl cellulose HEC, but HPAM,PVP and HEC had little change on the foaming capacity of the FS/AOS and even reduced itsfoaming capacity. Secondly, the adsorption properties in montmorillonite of the FS werestudied. Effects of salt, alcohol, polymers, pH, temperature, as well as kerosene on adsorptionwere researched and results show that short-chain alcohol was not conducive to FS adsorptionin montmorillonite, and long-chain alcohols and polyols were favorable. With pH valueincreasing, the FS adsorption in the montmorillonite decreased. With temperature increasing,the FS adsorption increased at first and then decreased, adsorption amount was maximum at40-50℃. With the increasing concentration of HPAM, FS adsorption in montmorillonitedeclined, and the molecular weight was more apparent. Then the FS expansion viscoelasticitywas studied at the gas-liquid surface and the oil-water interface. Effects of frequency,concentration, salt and alcohol on the FS expansion viscoelasticity were researched andresults show that with frequency increasing the FS dilational modulus and expansionflexibility were increased, salt and alcohol could reduce the original solution dilationalmodulus and expansion flexibility while increase expansion viscosity and phase angleexpansion modulus at the gas-liquid surface, but to reduce the original solution dilationalmodulus, expansion flexibility and expansion viscosity while increase phase angle expansionmodulus at the oil-water interface. Finally, the flooding system is FS:AOS=1:5(0.2wt%)+1000mg/LHPAM(molecular weight 10 million). Laboratory foam flooding and resultsshow that Fluorocarbon surfactant flooding could raise recovery by 30% based on waterflooding. Therefore, the fluorocarbon surfactant and its complex system have greatapplication potential, broad application prospect and market value in the tertiary oil recoveryfield.