Preparation And Study On Novel Nonaromatic Sulphonates In Enhanced Oil Recovery

With the rapid economic developing,China's growing energy demand has become increasingly conspicuous.Now,large-scale application of new energy can't be realized and traditional energy is becoming shortage.Under this situation,greatly enhance oil recovery technology has become a major oil research topics.Obviously,the surfactant which is used in tertiary oil recovery,become one of the important research focuses.Presently,the main surfactants used in enhanced oil recovery usually possess aromatic rings and can not be bi-degraded and be harmful to environment.The primary object of this dissertation is to design and synthesize some novel nonaromatic sulphonates which can be used in enhanced oil recovery.The novel sulphonates should be environment-friendly and biodegradable.Additionally,they have excellent ability to reduce the interfacial tension between crude oil and water.The novel sulphonates which are ester sulphonate and naphthenic petroleum sulphonate,through many experiments and reaction rout optimization,were designed and prepared in laboratory using ester or naphthenic oil reacted with fuming sulfuric acid followed by hydrolysis.The structures of two products were characterized by infrared spectra and ¹H nuclear magnetic resonancemain,at the same time,the main functional groups were approved.The results showed that the double bonds in ester were sulphonated and then converted into the corresponding saturated hydroxy ester sulphonate followed by hydrolysis when ester reacted with fuming sulfuric acid and naphthenic petroleum sulphonate was obtained through substitution reaction after naphthenic oil reacted with fuming sulfuric acid.The interfacial activities of the two products were evaluated.It revealed that the two products had excellent capacities and efficiencies to lower the tensions of oil-water interface of block 1.and block 2.in Shengli oilfield to ultra-low without alkaline and any other additives.The interfacial tension between crude oil and water could be reduced as low as 10^-3mN/m and the minimum interfacial tension was up to 5×10^-4mN/m.Furthermore,the two products possessed outstanding salt-resisting capacitis as well.The ester sulphonate could reduce interfacial tension between oil and water to 10^-3 mN/m even with the concentration of NaCl between 2000mg/L～130000 mg/L or with the concentration of Ca²⁺,Mg²⁺ below 500mg/L,and the naphthenic petroleum sulphonate could reduce interfacial tension between oil and water to 10^-3 mN/m even with the concentration of NaCl between 2000mg/L～50000mg/L or with the concentration of Ca²⁺,Mg²⁺ below 500mg/L.The two products were expected to be used in enhanced oil recovery applications.The equivalent alkane carbon number(EACN) was tested in part of Shengli Oilfield Area and the minimum number of alkane carbon(n_min) of the two surfactants were measured.The relationships between surfactant molecular structure and ability in lowering surface tension were investigated.All of this could provide theoretical fundamentals for designing new surfactant molecules in enhanced oil recovery.