Abstract: Nanosilicon dioxide was organic modified with silane coupling agent KH550. The influence of modification conditions on surface ζpotential of nanosilicon dioxide was characterized by Zetasizer 3000. The modified nanosilicon dioxide was respectively compounded with petroleum sulfonate. The ability of the composite system for reducing the oil water interfacial tension was measured by interfacial tensiometer TX500. Turbiscan Lab was applied to analyze the stability of oilwater emulsion. The results showed that petroleum sulfonate system could reduce the oil water interfacial tension to about 2.30×10-2mN/m, and modified nanosilicon dioxide and petroleum sulfonate composite system could reduce that to about 5.42×10-3 mN/m, when the concentration of surfactant was 0.5% and the modified nanosilicon dioxide surface zeta potential was -50.1 mV. The oilwater interfacial tension change and mechanism of emulsion stability were analyzed through the changes of surface zeta potential of modified nanosilicon dioxide. 

Key words: Nanosilicon dioxide,     , Modification,    , ζ Potential,    ,  Combination flooding system,    , Emulsion stability

摘要： 使用硅烷偶联剂 KH - 5 5 0对纳米二氧化硅( N a n o - S i O2) 进行表面有机改性。使用Z e t a s i z e r3 0 0 0电位 仪, 系统分析 KH - 5 5 0的用量、 改性时间以及改性温度等因素对 N a n o - S i O2 表面ζ电位的影响, 得到不同改性条件对 N a n o - S i O2 表面ζ电位的作用规律, 从而建立改性 N a n o - S i O2 表面ζ电位与有机改性条件的关系。将改性前后的 N a n o - S i O2 与石油磺酸盐 - P S复配, 得到改性二氧化硅/表面活性剂( KH 5 5 0 - g - N a n o - S i O2 - P S) 复合体系。采用界面 张力仪( TX - 5 0 0 c ) , 系统研究该复合体系降低油/水界面张力能力, 并利用T u r b i s c a nL a b型乳状液稳定性分析仪, 系 统研究油/水乳状液的稳定性。结果表明, 当石油磺酸盐表面活性剂质量分数为0. 5%时, 该体系油/水界面张力降 低至2. 3 0×1 0-2 mN /m, 然而当KH 5 5 0质量分数为5%时, KH 5 5 0 - g - N a n o - S i O2 - P S体系能使油/水界面张力降低至 5. 4 2×1 0-3 mN /m, 达到超低界面张力, 且乳化液稳定性最大, 此时 KH 5 5 0 - g - N a n o - S i O2 - P S体系表面ζ 电位为 -5 0. 1mV, 通过表面ζ电位的变化分析了油水界面张力变化及乳状液稳定机理。

关键词: 纳米二氧化硅,  , 有机改性,  , ζ电位, 复合驱油体系,  , 提高采收率