聚氧丙烯壬基酚醚硫酸酯盐/碱体系与原油动态界面张力研究

合成了聚氧丙烯壬基苯酚醚硫酸钠,研究了有机碱、无机碱以及所合成表面活性剂和有机碱、无机碱复配体系与桩西普通稠油的动态界面张力行为.结果表明:使用碳酸钠、三甲胺、三乙胺都可改变油水界面张力.碳酸钠/原油界面张力曲线呈"S"型变化,可分为缓慢上升、迅速上升和相对平衡3个阶段,而有机胺/原油界面张力曲线呈"U"型变化,出现动态界面张力最小值.碳酸钠加量不同时,其动态界面张力曲线变化不大;胺的质量分数升高时,动态界面张力则表现出先降低、后升高的趋势,存在最佳的胺加量.对于表面活性剂与Na2CO3复配体系,当Na2CO3加量高于一定临界值时,复配体系才有明显协同效应,此时仅需添加质量分数为0.0025%表面活性剂就可以将油水界面张力降低到10-5mN/m数量级.对于表面活性剂与有机胺的复配体系,降低油水界面张力的能力取决于体系中有机胺和表面活性剂的含量.只有当复配体系中有机胺的质量分数高于0.05%、9AS-3-0的质量分数低于0.01%时,复配体系才具有协同效应.上述研究说明:由有机碱和原油组分在油水界面反应生成的表面活性物质,其界面活性以及和聚氧丙烯壬基苯酚醚硫酸钠复配体系的界面张力行为与加无机碱的情况是不同的.另外,通过驱油试验证明,具有较低动态界面张力的9AS-3-0/Na2CO3复配体系有高的提高采收率的能力.

Study on the dynamic interfacial tension between crude oil and the aqueous solution of polyoxypropylated nonylphenol sodium sulfate / alkali

A new surfactant--polyoxypropylated nonylphenol sodium sulfate is synthesized.The dynamic interfacial tensions between inorganic alkali,organic alkali and a compound system of inorganic alkali or organic alkali with the surfactant and the heavy crude oil from Zhuangxi Production Plant are studied separately.The results show that the dynamic interfacial tension between water and crude oil can be reduced by ether inorganic alkali or organic alkali.The dynamic interfacial tension between crude oil and the aqueous solution of sodium carbonate varies with time,and the interfacial tension--time curve shows the shape of "S",it includes three segments:slowly rising segment,rapidly rising segment and relatively stable segment.However,the dynamic interfacial tension curve between the aqueous solution of amine and the crude oil presents the shape of "U",there is a minimum value in the curve.For the compound system of polyoxypropylated nonylphenol sodium sulfate with sodium carbonate,interfacial tension between water and the crude oil can be reduced greatly only when the concentration of sodium carbonate is higher than a certain threshold value.In the compound system,only the mass fraction of polyoxypropylated nonylphenol sodium sulfate of 0.002 5% can make the interfacial tension be reduced to the order of 10-5 mN/m.For the compound system of polyoxypropylated nonylphenol sodium sulfat with amines,only when the mass fraction of the amine is more than 0.05% and the mass fraction of the surfactant is less than 0.01%,there is a synergistic effect between the amine and the surfactant to reduce the interfacial tension.These results indicate that the interfacial activities of the surfactants produced by the reactions of inorganic alkali and its compound system with the new surfactant synthesized with the crude oil are different from those of the surfactants produced by the reactions of organic alkali and its compound system with the new surfactant synthesized with the crude oil.Moreover,oil displacement tests show that the compound of polyoxypropylated nonylphenol sodium sulfate with sodium carbonate has low interfacial tension hither oil displacement efficiency.