砂岩表面zeta电位与渗流过程的关系

The relationship between zeta potential of sandstone surface and porous flow process

目的研究储油砂岩表面的zeta电位对油水渗流过程的影响。方法用电渗法测量砂岩表面的zeta电位,用岩心驱替法测渗流过程。结果加入季铵盐型阳离子表面活性剂对砂岩表面的电性具有较大的影响,随着阳离子表面活性剂浓度的增加,砂岩表面的负电性逐渐减弱至不带电,最后变为正电。十八烷基三甲基氯化铵驱油实验证明:zeta电位与渗流过程关系密切,零电位时,油的渗流最好,有利于残余油的驱出。结论zeta电位影响着渗流过程,零电位对渗流过程最有利,驱油剂对砂岩表面电性的影响较大。

Aim To study the effect of surface zeta potential of reservoir sandstone to porous flow process of water and oil. Methods The zeta potential was measured by electroosmosis method, and the porous flow process was measured by core displacement test. Results Usually reservoir sandstone surface is electronegative. Inserted quaternary cationic surfactant greatly affects the surface of electrical behavior of sandstone. With the cationic surfactant concentration increasing, the surface of electrical behavior of sandstone varies from electronegative to electroneutral and to electropositive in the end. The later displacing tests using （CH3）4（CH2）18NCl showed that the relationship between zeta potential and porous flow process is close ： the porous flow of oil is the best when zeta potential is zero because the phenomenon against displacing such as electric suction and electric repulsion disappears, favor to displacing residual oil. Conclusion Zeta potential affects the porous flow process, and zero zeta potential is most favorable. So it is necessary to have a regard for the effect of oil displacement agent to sandstone surface electrical behavior.