聚驱后超低界面张力泡沫复合驱实验研究

Experimental study on foam compound flooding of ultra-low interfacial tension after polymer flooding

为研究聚驱后超低界面张力泡沫复合驱提高采收率的效果,在大庆油田的油水条件下,用界面张力仪和泡沫评价仪评价了二元发泡剂体系的界面性能和泡沫性能,用泡沫驱油装置研究了聚合物浓度和交替周期对泡沫复合驱效果的影响.实验结果表明,二元发泡剂体系在较宽的表面活性剂和聚合物浓度范围内可以与原油形成超低界面张力.同时二元发泡剂体系具有非常好的泡沫综合指数.聚驱后二元泡沫复合驱可提高采收率15%以上.聚驱后二元泡沫复合驱的气液交替周期越小采收率越高,且气液同注泡沫驱效果最好.在表面活性剂和聚合物用量相同条件下,二元泡沫复合驱效果好于三元泡沫复合驱、二元液驱及高浓度聚驱,且避免了强碱带来的腐蚀、结垢等问题.

In order to study the result of enhancing recovery factor by ultra-low interfacial tension foam compound flooding after polymer flooding,the interfacial activity and foam stability of binary foaming agent system were studied under Daqing oil reservoir condition by interfacial tension instrument and foam evaluation instrument.The effects of polymer concentration and alternate cycle on flooding result were discussed.The results show that,the ultra-low interfacial tension between crude oil and binary foaming agent system is acquired in the wide concentration range of surfactant and polymer,and that the binary foaming agent system has a very good foam composite index.The binary foam compound flooding can enhance oil recovery factor more than 15%.The shorter the gas/liquid alternate cycle is,the higher the enhanced recovery factor is.The result of the foam compound flooding is the best when gas and liquid is simultaneously injected.Under the same dosage of surfactant and polymer,the binary foam compound flooding is better than that of ternary foam compound flooding,binary liquid flooding and high concentration polymer flooding.And the binary foam compound flooding can avoid alkali corrosion,scaling and other problems.