碱对超低界面张力形成及界面膜扩张流变性的影响  

THE EFFECT OF ALKALI ON THE FORMATION OF ULTRA LOW INTERFACIAL TENSION AND DISTENTION RHEOLOGY BEHAVIOR OF INTERFACIAL FILM

作　　者：马丽[1] 侯吉瑞[1] 赵凤兰[1] 刘立伟 

机构地区：[1]中国石油大学提高采收率研究中心,北京102249 [2]中海石油研究中心,北京100027

出　　处：《大庆石油地质与开发》2010年第6期149-154,共6页Petroleum Geology & Oilfield Development in Daqing

基　　金：基金项目：国家重点基础研究发展计划（“973”计划）（2005CB221303）资助.

摘　　要：对于HABS（重烷基苯磺酸盐）／碱二元体系，水相中的碱能与原油中的酸性物质反应生成具有活性的石油酸皂，石油酸皂与HABS分子都能吸附到界面上，通过二者的协同作用，使界面张力达到超低。表面活性剂分子扩散进入水相和油相，其吸附和脱附的相对扩散速率大小与动态界面张力有很大关系。在某一时间油水吸附层吸附的活性剂分子个数最多，对应的界面张力达到最低值。通过研究原油与二元体系预接触时间对动态界面张力的影响程度，得到了酸性物质在油水界面上的扩散规律，并利用线性拟合证明σ（界面张力）与t-1/2（时间）成直线关系，得到相应的预测模型，证明该过程实际是一个动态的扩散过程，而生成的石油酸皂有助于HABS在界面上的吸附排列；另外，探讨了加入碱前后的油水界面扩张黏弹模量的变化实验，实验发现，加入碱之后界面膜扩张模量升高3～4倍，可以推测碱的加入使更多的活性剂离子聚集在界面上使界面膜强度增大，而且该界面膜界面扩张黏性和弹性也与界面附近及界面上各种微观弛豫过程的特征时间密切相关。实验结果对于明确碱在超低界面张力形成中的作用机理具有一定意义。For the HABS/alkali system, the alkali of aqueous phase can react with the acidic materials in the oil to produce the active petrol-soap, both which and HABS can be absorbed to the interface, causing ultra low IFT. When the surfactant molecules disperse into oil phase and water phase, the relative adsorbing and stripping diffusion rates are controlled by dynamic IFT. At some time the adsorption layer adsorbs the largest number of surfactant molecules, and then the corresponding interracial tension can reach the lowest value. The effect of the pre-contact time of oil and the binary system on the dynamic IFT has been studied, and the diffusion rules of the acidic materi-als on the OWC have been obtained. Based on linear matching, it has been proved there is linear relationship between σ （interracial tension） and t-1/2 （time） with the corresponding forecast model. It has been demonstrated that the above process is one kind of dynamic diffusion process and the petro-soap produced contributes to the adsorbing alignment of HABS on the interface. Moreover, the changes of the viscoelastic modulus caused by the oilwater interfacial dilation with and without alkali have been discussed. The experimental results demonstrate, after adding alkali the dilation viscoelastic modulus of interfacial film increase 3 -4 times. So, it can be supposed that with the existence of alkali more active agent irons will focus on the interface, leading to higher interfacial film intensity, and the interracial distension viscosity and elasticity of this interfacial film are closely related with the characteristic time for various microcosmic relaxation processes on the interface and near the interface. The experimental results are significant for determining the mechanism about alkali contributing to the formation of ultra low interfacial tension.

关 键 词：超低界面张力 石油酸皂 界面膜扩张模量 重烷基苯磺酸盐 

分 类 号：TE357.46[石油与天然气工程—油气田开发工程]