Abstract In this work, petroleum sulfonate (PS), which can be used for enhanced oil recovery (EOR), was synthesized by sulfonation of distillate oil using gaseous SO3 in a rotating packed bed. The prepared PS was characterized by FT-IR, NMR, negative electrospray ionization fourier transform ion cyclotron resonance mass spectrometry [(−) ESI FT-ICR MS] and thermal gravimetric analysis (TGA). Results showed that the PS contains N1, O1, O2, O3, N1O2, O3S, O4S, and N1O3S classes, among which O3S, O4S, and N1O3S are the three main classes. And the chemical composition of the PS was obtained by the combined analysis of the double-bond equivalent (DBE) and carbon number (CN). TGA results showed that PS is thermally stable at the conventional reservoir temperature (less than 200 °C). In addition, the EOR performance of PS was studied by measuring surface tension, interfacial tension (IFT), wettability alteration and core-flooding experiments. Critical micelle concentration (CMC) of the prepared PS with a value of 0.2% was also determined by surface tension method. An ultra-low oil-water IFT value 1.327 × 10−3 mN/m was obtained at the CMC of PS solution. It was also found that adding PS into brine can decrease the contact angle below 90°, indicating that it can alter the rock wettability from oil-wet to water-wet surface which contributes to enhancing oil recovery. Finally, core-flooding experiments were carried out with different PS concentrations. The results showed that an additional recovery of about 30% after conventional water flooding can be obtained at a PS concentration of 0.3%. This study indicated that the PS synthesized by gas-phase SO3 sulfonation in RPB has good EOR performance, and the work is helpful for the learning of the relationship between PS composition and EOR performance and give the guidance for PS’s synthesis.

中文翻译：

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旋转填充床气相三氧化硫磺化合成石油磺酸的表征及其在提高采油率中的应用

摘要 在这项工作中，通过在旋转填充床中使用气态 SO3 磺化馏出油，合成了可用于提高石油采收率 (EOR) 的石油磺酸盐 (PS)。制备的 PS 通过 FT-IR、NMR、负电喷雾电离傅立叶变换离子回旋共振质谱 [(-) ESI FT-ICR MS] 和热重分析 (TGA) 进行表征。结果表明，PS包含N1、O1、O2、O3、N1O2、O3S、O4S和N1O3S类，其中O3S、O4S和N1O3S是三个主要类。并且通过双键当量（DBE）和碳数（CN）的组合分析得到PS的化学成分。TGA 结果表明 PS 在常规储层温度（低于 200 °C）下是热稳定的。此外，通过测量表面张力、界面张力（IFT）、润湿性改变和岩心驱油实验研究了PS的EOR性能。所制备的 PS 的临界胶束浓度 (CMC) 值为 0.2%，也采用表面张力法测定。在 PS 溶液的 CMC 处获得了超低油水 IFT 值 1.327 × 10−3 mN/m。还发现在盐水中加入 PS 可以将接触角降低到 90°以下，表明它可以将岩石润湿性从油湿表面改变为水湿表面，有助于提高石油采收率。最后，用不同的 PS 浓度进行了岩心驱油实验。结果表明，在0.3%的PS浓度下，常规注水后可获得约30%的额外采收率。