离子种类和质量浓度对不同温度稠油油水界面张力影响的实验研究

为了研究在不同温度下离子种类和质量浓度对稠油油水界面张力的影响,分别配制了含不同质量浓度Na+、Ca2+、Mg2+的盐水溶液,应用旋转油滴法测量了不同温度时稠油与盐水的界面张力,分析了温度、离子种类与质量浓度对界面张力的影响规律.实验结果表明:①盐水成分为Na+和Mg2+时,随离子质量浓度的增大,界面张力先减小后增大,存在极小值;成分为Ca2+时,界面张力先增大后稳定再增大.②随温度升高,在Na+和Ca2+作用下界面张力明显减小,在Mg2+作用下先减小后稳定.③温度和离子质量浓度均影响界面张力;离子质量浓度低时界面张力主要受温度影响;离子质量浓度高时在Na+作用下界面张力受温度影响较大,在Ca2+作用下界面张力受温度的影响减弱;在Mg2+作用下界面张力受离子质量浓度的影响较大.

Experimental study on the effects of the composition and mass concentration of ions and temperature on the interfacial tension between heavy oil and brine water

The brine water containing Na+,Ca2+,Mg2+ ions of different mass concentrations were prepared for studying the effect of the composition and mass concentration of ions and temperature on the interfacial tension between heavy oil and brine water.The interfacial tension(IFT)was measured by rotating oil droplets method at different temperature.The influence rules of temperature,ion species and ion mass concentration to the IFT were discussed.The experimental results show:① the IFT between heavy oil and the brine water containing Na+ or Mg2+decreases initially and then increases with the increase of the ion mass concentration,there is a minimum IFT value;the IFT between heavy oil and the brine water containing Ca2+ increases initially,then stabilizes,and finally increases again with the increase of the ion mass concentration.②the IFT between heavy oil and the brine water containing Na+or Ca2+ decreases obviously with the rise of temperature,while the IFT between heavy oil and the brine water containing Mg2+decreases initially and then stabilizes with the rise of temperature.③ the IFT between heavy oil and brine water is controlled by both temperature and ion mass concentration.At low ion mass concentration,the IFT is mainly affected by temperature,while at high ion mass concentration,temperature has greater effect on the IFT between heavy oil and the brine water containing Na+ and it has less effect on the IFT between heavy oil and the brine water containing Ca2+,while ion mass concentration has greater effect on the IFT between heavy oil and the brine water containing Mg2+.