不同界面性质表面活性剂体系提高采收率作用效果和机理

Enhanced Oil Recovery Effect and Mechanism of Surfactants with Different Interfacial Property

刘倩 张金晶 石华强 李小玲 管保山 梁利

LIU Qian ZHANG Jinjing SHI Huaqiang LI Xiaoling GUAN Baoshan LIANG Li

为明确不同界面性质对提高采收率作用效果和机理的影响，以长6 低渗致密储层为研究对象，选用两种具 有不同界面性质的自制表面活性剂体系S1（改善润湿性能力强）和S2（超低界面张力），分别用核磁共振方法表 征其静态渗吸和动态渗吸效果，并采用2.5 维微观模型研究其驱油过程，分析了具有不同界面性质表面活性剂体 系的提高采收率作用效果和作用机理。结果表明，S1 和S2 均具有较好的增采效果，渗吸为水进入小孔隙将油置 换到大孔隙的过程，表面活性剂可大幅促进小孔隙采出；驱油时形成优势通道明显，可实现润湿反转，存在附加 渗吸作用，大幅增大波及体积和洗油效率，并能将原油分散为小尺度状态。改善润湿性能力更强的S1 的毛细管 动力更大，对小孔隙的动用程度更高，但采出速度较慢，驱替时存在的附加渗吸作用更强；可实现超低界面张力 的S2油相流动阻力更小，渗吸速度快，采收率可更快达到平衡。

In order to clarify the effect and mechanism of different interface properties on EOR，taking the low permeability tight reservoir of Chang 6 as the research object，two self-made surfactants S1（strong modification wettability）and S2（ultra-low interfacial tension） with different interfacial property were selected. Their static and dynamic permeability effects were characterized by nuclear magnetic resonance（NMR），and their oil displacement process was studied by 2.5-dimensional micro model. The EOR effect and mechanism of S1 and S2 were analyzed. The results showed that both S1 and S2 had good enhanced production effects. Imbibition was a process in which water entered small pores to replace oil to large pores. Surfactants could greatly promote the production of small pores. During oil flooding，the dominant channel obviously formed，which could realize wettability reversal. The additional imbibition effect greatly increased the sweep volume and oil washing efficiency，and could disperse the crude oil into small scale state. Among them，the capillary force of S1 with stronger wettability ability was more powerful and had a higher degree of mobilization of small holes，but the recovery rate was slower. While the additional imbibition during displacement was stronger. The S2 with ultra-low interfacial tension could achieve smaller oil phase flow resistance，faster imbibition speed，and faster recovery to reach equilibrium.

10.19346/j.cnki.1000-4092.2022.04.019