驱油剂对无碱三元复合驱采出液乳化稳定性影响

Impact of oil-displacing agent on the emulsification stability of oily wastewater in alkali-free ternary composite flooding

为探究无碱三元驱油剂对于采出液乳化稳定的机理,为采出液处理提供依据。对游离水中含油量、油水动态界面张力、液滴界面寿命与油滴粒径分布状态及粒径随驱油剂含量的变化进行了研究。加入低浓度表面活性剂(100 mg/L)时,动态界面张力、界面寿命、油滴粒径均显著降低,水中含油量显著增加,随着表面活性剂浓度增加,动态界面张力、界面寿命、粒径、含油量变化均不明显;随着NaCl浓度上升,动态界面张力与界面寿命变化不明显,油滴粒径变大,水中含油量增加;随着聚合物浓度增加,动态界面张力与界面寿命变化不明显,对于油滴粒径与含油量出现双重作用。这表明表面活性剂与NaCl有利于乳化稳定,但表面活性剂作用远大于NaCl;低浓度聚合物不利于乳化稳定,随着浓度增加,有利于乳化稳定。

In order to investigate the mechanism of alkali-free ternary oil-displacing agents in stabilizing the emulsification of produced fluids and to provide a basis for the treatment of these fluids,a study was conducted.This study focused on the oil content in free water,the dynamic interfacial tension between oil and water,the lifetime of droplet interfaces,and the distribution state and size variation of oil droplets as influenced by the concentration of the displacement agent.It was found that upon the addition of a low concentration of surfactant(100 mg/L),a significant reduction in dynamic interfacial tension,interface lifetime,and oil droplet size was observed,along with a significant increase in the oil content in water.As the concentration of the surfactant increased,changes in dynamic interfacial tension,interface lifetime,particle size,and oil content became less noticeable.With an increase in NaCl concentration,there were insignificant changes in dynamic interfacial tension and interface lifetime,but an increase in oil droplet size and the oil content in water was observed.Furthermore,an increase in polymer concentration led to insignificant changes in dynamic interfacial tension and interface lifetime,but exerted a dual effect on oil droplet size and oil content.These findings indicate that surfactants and NaCl contribute to the stabilization of emulsions,with the effect of surfactants being substantially greater than that of NaCl.Low polymer concentrations are not conducive to emulsion stability,but as their concentration increases,they become beneficial for emulsion stabilization.