三元复合驱采出液稳定机理研究

Stabilizing Mechanism Study on the Produced Liquid of ASP Flooding

三元复合驱采出液是一种复杂的水包油型乳状液,残留的驱油药剂使其破乳十分困难。为此,采用微观液滴群测试系统捕捉油滴群的粒径分布,用来表征不同驱油剂浓度对采出液的稳定性的影响。结果表明:采出液稳定性随连续相pH值的增大呈现先增强后减弱趋势,当pH=10.0时,采出液稳定性最强;表面活性剂对采出液稳定性的影响与其临界胶束浓度有关,浓度低于临界胶束浓度时,增大表面活性剂浓度有利于采出液的稳定,但超过临界胶束浓度后,增大表面活性剂浓度反而使得采出液稳定性变差;聚合物对采出液稳定性的影响是双重的,浓度较低时,其絮凝作用起主导作用,聚合物浓度增大,采出液稳定性变差,但其浓度较高时,空间位阻、双电层作用以及连续相的高黏度使得采出液稳定性增强。

The produced liquid of Alkali-Surfactant-Polymer flooding is a complicated O/W emulsion.Residual flooding agents make it hard to demulsify.The micro droplet test system is used to seize its distribution in order to research different agents which have influence on the stabilizing mechanism.Results show that if the continuous phase pH value increases,the stability of the produced liquid will rise and then weaken.When the pH value is 10,the produced liquid has the strongest stability.The influence of surfactant on the stability of the produced liquid is related to its critical micelle concentration.If surfactant concentration is less than critical micelle concentration,increasing surfactant concentration is good for the stability.However,if its concentration exceeds CMC,increasing surfactant concentration is bad for the stability.Polymer has a double influence on the stability of the produced liquid.When its concentration is low,flocculation effect plays a leading role,and the stability is weakened.If its concentration is high,steric hindrance,electric double layer,and the high viscosity of continuous phase will strengthen the stability of the produced liquid.