渤海某油田驱油用超低界面张力表面活性剂研究

Research of ultra-low interfacial tension surfactant for oil displacement in an oilfield of Bohai

关键词:  碳原子数分布  超低界面张力  表面活性剂  采收率 

Key words:  carbon atom number distribution  ultra-low interfacial tension  surfactant  oil recovery

摘要:

目的 为改善渤海X油田注水开发效果,对该油田进行了驱油用超低界面张力表面活性剂研究。方法 在分析油田原油饱和分和芳香分碳原子数分布基础上,结合“相似相溶”原理和疏水端空间位置互补效应,对表面活性剂进行优选和复配。结果 从5种表面活性剂中优选出了十六烷基二甲基甜菜碱和烷基糖苷APG1214两种表面活性剂,二者按最佳质量比1∶2复配后可获得超低界面张力表面活性剂。该表面活性剂在岩心中滞留损失率小,仅为11.2%；在质量分数为0.1%~0.3%时,原油的乳化和破乳率均高于90%；当质量分数为0.20%时,可在水驱基础上提高原油采收率9.4%。结论 复配表面活性剂降水增油效果明显,可用于实现油田水驱后“挖潜提采”的目的。 

Abstract:

Objective In order to improve the water flooding efficiency, a study on ultra-low interfacial tension surfactant for oil displacement in Bohai X Oilfield was carried out. Methods According to the carbon atom number distribution analysis results of the saturated fraction and aromatic fraction of the crude oil, combining the principle of "similar phase dissolution" and the spatial complementary effect of hydrophobic end, the selection and mixing experiments of surfactants were carried out. Results Hexadecyl dimethyl betaine and alkyl polyglycoside APG1214 were selected out from 5 surfactants. The ultra-low interfacial tension surfactant can be obtained by mixing the two surfactants at the mass ratio of 1∶2. The retention loss rate of obtained composite surfactant in core was small, which was only 11.2%. The emulsification and demulsification rates of crude oil were higher than 90% when the concentration of the composite surfactant was 0.1%-0.3%. The oil recovery can be increased by 9.4% over water flooding at the concentration of 0.2%. Conclusion sThe field test results showed that the composite surfactant can obviously decrease water cut and increase oil production, it can be used to realize the purpose of "tapping the potential and increasing production" after water flooding in the oilfield.