耐垢碱/表面活性剂复合体系与桩西原油的界面张力研究

Study on Interfacial Tensions between the Compound System of Antiscale Alkali/Surfactant and Zhuangxi Oil

针对胜利油田桩西区块地层水钙、镁含量高的问题,通过测定耐垢碱与表面活性剂复合体系与桩西原油间的动态界面张力,形成了适合该区块的超低界面张力驱油体系。结果表明,单一表面活性剂和桩西原油的界面张力均无法达到超低水平,其中当质量分数为0.1%的CBET-17,降低界面张力能力最好,界面张力能达到7.5×10-2m N/m左右;由不同浓度偏硼酸钠和0.1%表面活性剂复合体系与桩西原油的界面张力表明,当浓度0.4%偏硼酸钠与0.1%CBET-17或者0.1%SLPS复配时,油水界面张力都能达到超低水平。同时由于偏硼酸钠具有耐垢性,可螯合地层水中的钙、镁离子,使得复合体系具有很好的耐垢能力,可以适合于胜利油田桩西区块的驱油。

For the high calcium and magnesium contents in the formation water of Zhuangxi block in Shengli Oil Field, the dynamic interfacial tension between anti-scaling alkali and surfactant composite system and Zhuangxi oil is measured, and ultra-low interracial tension flooding system is developed for this block. The results show that ul- tra-low interfacial tension can＇t be gained by using a single surfactant, 0. 1% CBET-17 has the better performance and the interfacial tension can reach 7.5 × 10^-2 mN/m. The interfacial tension between Zhuangxi oil and the com- posite system of 0. 1% surfactant and NaBO2 of different contents shows that, when 0. 1% CBET-17 or 0. 1% SLPS blended with 0.4% NaBO2 is used, ultra-low interracial tension can be easily got. NaBO2 exhibits good scaling re- sistance and can chelate calcium and magnesium ions in the formation water. It makes good sealing resistance of the compound system, which is suitable for the oil flooding in Zhuangxi block in Shengli Oil Field.