表面活性剂提高致密油藏渗吸采收率研究

Improvement of Spontaneous Imbibition Oil Recovery in Tight Oil Reservoir by Surfactants

沈安琪 刘义坤 邱晓惠 卢拥军 崔伟香 梁爽

SHEN Anqi LIU Yikun QIU Xiaohui LU Yongjun CUIWeixiang LIANG Shuang

为了明确表面活性剂改变岩石润湿性及降低界面张力的特性对致密油藏渗吸采油的作用效果，获得表面活性剂渗吸采油的有利条件，通过测量岩心接触角和表面活性剂溶液与油间的界面张力，研究了3 种常用表面活性剂重烷基苯石油磺酸盐（ZPS）、十二烷基苯磺酸盐（SDBS）和磺基甜菜碱（SB）对致密岩心渗吸采收率的影响，分析了自发渗吸机理。结果表明，阴离子表面活性剂改变岩心润湿性的能力好于非离子表面活性剂，两种阴离子表面活性剂（ZPS、SDBS）将岩心表面由油湿反转为水湿，非离子表面活性剂（SB）降低了岩心表面接触角，但未达到润湿反转的效果；油湿岩心介质在注入水溶液中不发生渗吸，表面活性剂引起的接触角改变可实现油湿岩心渗吸采油；岩心原始润湿性影响渗吸采收率，渗吸采收率增幅从大到小依次为水湿岩心>中性岩心>油湿岩心；三种表面活性剂均可使界面张力降至最佳渗吸界面张力范围10-1～10-2mN/m，油水界面张力的降低有利于提高岩心自发渗吸采收率。图1 表1 参12

In order to determine the effect of lower interfacial tension and wettability alteration upon tight oil cores imbibition，and obtain favorable condition of surfactant imbibitions，the effects of three kinds of surfactants，including heavy alkylbenzene petroleum sulfonate（ZPS），dodecyl benzene sulfonate（SDBS）and sulphobetaine（SB），on the imbibition efficiency of tight cores and the mechanism of spontaneous imbibition were studied by measuring the contact angle of cores and the interfacial tension between oil and surfactant solution. The results showed that the three kinds of surfactants solution improved oil recovery in some degrees contrasted with injected water solution. Two anionic surfactants（ZPS，SDBS）had the effect of wettability alteration， nonionic surfactant（SB）reduced the contact angle，but was not able to make the core water-wet. Oil-wet core did not occurred imbibition in water solution，while it realized imbibition when the wettability alteration caused by surfactant. The original wettability of cores affected the imbibition efficiency. Three cores were arranged according to their effect on the increase of imbibition efficiency in following order: water-wet core>neutral-wet core>oil-wet core. Three kinds of surfactant could lower the interfacial tension to the best range of interfacial tension of imbibitions which was 10-1—10-2 mN/m. The decrease of oil-water interfacial tension was beneficial to the increase of spontaneous imbibition efficiency.

10.19346/j.cnki.1000-4092.2016.04.025