表面活性剂对低渗透油藏渗吸敏感因素的影响

The Effect of Surfactants on Imbibition-Sensitive Factors of Low-Permeability Reservoirs

李洪 李治平 王香增 王才 白瑞婷

LI Hong LI Zhiping WANG Xiangzeng WANG Cai BAI Ruiting

非常规天然气能源地质评价与开发工程北京市重点实验室(中国地质大学(北京)), 北京 100083; 陕西延长石油(集团)有限责任公司研究院, 陕西西安 710075

Beijing Key Laboratory of Unconventional Natural Gas Geology Evaluation and Development Engineering(China University of Geosciences(Beijing)), Beijing, 100083, China; Research Institute of Shaanxi Yanchang Petroleum(Group) Co., Ltd., Xi’an, Shaanxi, 710075, China

界面张力和岩石润湿性是影响毛细管压力大小的决定性因素，因此研究表面活性剂对这两个因素的影响，可以充分发挥渗吸作用、提高低渗透油田原油的渗吸采收率。利用7块不同渗透率的亲水人造岩心，通过渗吸试验、旋滴法和动态接触角法研究了表面活性剂对油水界面张力、水湿表面润湿性、毛细管压力以及渗吸采收率的影响。试验结果发现：随着表面活性剂RS-1质量分数的增大，油水界面张力先有较大幅度降低后略有升高，最后趋于平稳；表面活性剂具有很强的改变水湿表面润湿性的能力，且能降低毛细管压力、提高渗吸采收率。研究结果表明：表面活性剂降低界面张力效果明显，并且复配表面活性剂降低界面张力的效果比单一活性剂好，岩样渗吸采收率与油水界面张力和毛细管压力的对数呈线性负相关关系。

Interfacial tension and wettability are decisive factors for capillary force. Identifying the effect of surfactants on interfacial tension and wettability can be beneficial in improving the oil imbibition recovery rate in low permeability reservoirs. In this study, the effects of surfactants on the oil-water interfacial tension, surface wettability, capillary pressure and imbibition recovery were investigated through imbibition tests, spinning drop and dynamic contact angle methods, with 7 hydrophilic artificial cores with different permeability. Research results suggest that oil-water interfacial tension decreases significantly as the mass fraction of surfactant RS-1 increases, and then increases slightly before eventually becoming stable. The surfactant is highly capable in water wet surface wettability change, and can reduce the capillary pressure and improve the imbibition recovery. Results indicate that the surfactant is ostensibly capable of reducing the interfacial tension, especially with mixed surfactants which can achieve better performance than individual surfactants. Imbibition recovery is negatively correlated with the logarithm of capillary pressures and interfacial tension.

国家自然科学“CO2驱油对储层的伤害机理研究”（编号：51174178）、北京市自然科学“超临界CO2对储层性质的改变及油气田开发的影响”（编号：3162026）资助。

https://doi.org/10.11911/syztjs.201605017