原油/表面活性剂体系界面扩张流变性影响因素研究

Influence Factors Study of Interfacial Dilatational Rheology between Crude Oil and Surfactant Solution

郑玉飞 蒋 平 裴海华 张贵才 姜瑞忠 汤明光

ZHENG Yu-Fei JIANG Ping PEI Hai-Hua ZHANG Gui-Cai JIANG Rui-Zhong TANG Ming-Guang

使用德国KRüSS公司生产的DSA100界面扩张流变仪，采用小幅周期振荡法考察了55℃时ORS-41表面活性剂溶液与桩西原油接触界面的界面扩张流变性。通过测量界面扩张模量、弹性模量和黏性模量等参数，研究了实验条件和表面活性剂对界面性质的影响。结果表明：油滴大小和振幅对实验结果的影响较小；界面上发生的主要弛豫过程为扩散弛豫，扩张模量、弹性模量和黏性模量均随着振荡频率的增大而增大。适宜的实验条件为：ORS-41表面活性剂溶液质量分数0.01%，油滴振幅1.0 μL，振荡周期10 s，表面活性剂平衡时间300 s。未加表面活性剂时，界面膜可以看作是弹性模，弹性模量和扩张模量分别为2.8409 mN/m和2.8490 mN/m，黏性模量近似为0。加入表面活性剂后，界面膜的弹性模量和扩张模量迅速降至0.1503 mN/m和0.1786 mN/m；而黏性模量则先增大后减小。

Interfacial dilatational rheology of the interface between ORS-41 surfactant solution and Zhuangxi crude oil was investigated by small periodic oscillation method at 55°C using DSA100 interfacial dilatational rheometer. The influence of experiment conditions and surfactant on interface properties was studied by measuring the parameters of interfacial dilatational modulus, interfacial elastic modulus and interfacial viscous modulus. The results showed that the droplet size and amplitude had slight influence on the experiment results. The main relaxation process which occurred on the interface was diffusion relaxation. Dilatational modulus, elastic modulus and viscous modulus increased with increasing oscillation frequency. The appropriate experiment condition was obtained as follows: 0.01% mass fraction of ORS-41, 1 μL amplitude of oil drop, 10 s oscillation period and 300 s equilibrium time of surfactant. The interfacial film could be seen as elastic film without ORS-41, and elastic modulus and dilatational modulus was 2.8409 mN/m and 2.8490 mN/m respectively, while viscous modulus was approximately zero. Dilatational modulus and elastic modulus of the interface film decreased sharply to 0.1503 mN/m and 0.1786 mN/m after adding ORS-41, but viscous modulus increased at first then decreased.