泡沫在多孔介质中的生成过程和形态研究

Study on the Generation Processes and Shapes of Foam in Porous Media

通过高温高压泡沫驱系统,模拟了油藏压力条件下泡沫在多孔介质中的生成过程,并借助于高温高压观察窗和CCD摄像装置对泡沫生成过程和形态进行观察。泡沫在多孔介质中的生成具有周期性,每个周期包括生成封堵、开始运移、稳定运移和结束4个阶段;多孔介质结构影响发泡器两端压差的形成,从而影响泡沫的生成,压差适中时泡沫生成好,兼具封堵和运移的能力,压差过小时不能生成很好的泡沫,压差过大时泡沫全部被封堵在发泡器中,不能进入岩心发挥作用。不同压力、气液比对泡沫形态的影响较大,压力增高时泡沫变小,在最优气液比时生成泡沫形态最好。

Foam generating process in porous media is simulated under oil reservoir condition by high temperature high pressure(HTHP) foam flooding system.The generation processes and shapes of foam are observed by the HTHP visual cell and CCD camera device.The results indicate that the foam is generated periodically,and every generation cycle includs four stages——generating and plugging,moving gradually,stable migration,and the end. The structure of porous media influences the differential pressure between foam generators and then influences the generations of foam.A minimum differential pressure is required to produce high performance foam which has better capabilities of plugging and migration.And if the differential pressure is too low,high performance foam will not be produced,if the pressure is too high,it indicates that the foam is all plugged in foam generator and thus will not enter in the core to performance.Then different experiment conditions—pressure,ratio of gas and liquid are studied.The result shows that the experimental pressure has a significant influence on the shapes of foam, higher pressure produce smaller foam.And an optimized ratio of gas and liquid to produce high performance foams has been confirmed.