基于非离子表面活性剂的高压CO_2泡沫稳定性试验

Experiment on high pressure CO_2 foam stability of nonionic surfactants

针对壬基酚聚氧乙烯醚系列非离子表面活性剂,利用高温高压可视化泡沫仪,在不同温度、压力和矿化度条件下对CO2泡沫性能进行测试,分析(聚氧乙烯基)EO聚合度、矿化度、压力和温度对CO2泡沫性能的影响。同时通过驱替试验对CO2泡沫作为驱油剂的封堵和流度控制能力进行测试,并与高温高压泡沫仪的试验结果进行对比,分析泡沫仪测试的泡沫综合性能指数与泡沫在驱替试验中的阻力系数的相关性。结果表明:随着EO聚合度的增大,表面活性剂的亲水性增加,所产生CO2泡沫的性能及稳定性提高;泡沫液矿化度增大、压力增大和温度升高都会导致CO2泡沫性能下降。驱替试验结果揭示了表面活性剂分子结构对CO2泡沫的影响,对CO2泡沫用非离子表面活性剂的设计和性能提高具有指导意义。

The performance of nonionic surfactants （nonylphenol ethoxylate series） used as CO2 foam agents was investigated using a high temperature and high pressure foam visualization meter under different temperature, pressure and salinity condi-tions. The influences of the polymerization number of ethylene oxide （EO） , temperature, pressure and salinity on foam per-formance were evaluated. The foam＇s blockage and mobility control ability were also tested in sandpack flooding experiments and the results were compared with the corresponding results obtained from the foam visualization meter. The correlation be-tween the comprehensive foam performance index tested by foam apparatus and resistance coefficient in displacement test was analyzed. The results show that the surfactant＇s hydrophilicity increases with the EO numbers increasing, which can improve CO2 foam performance and foam＇s stability. While the foam performance declines with salinity, pressure and temperature in-creasing. The displacement experimental results reveal some influences of surfactant＇s molecule structure on its foam perform-ance, which can provide guidance on designing and improving nonionic surfactants used as CO2 foam agents.