超微CO2泡沫制备与表征

Preparation and characterization of the ultra-micro CO2 foam

为提高低渗透油藏原油采收率,开展了低界面张力的超微CO2泡沫的制备方式优选。通过实验对比恒速搅拌和多孔介质2种类型5种发泡方式,考虑不同搅拌速率、填料粗细及填料类型等方法制备超微CO2泡沫,优选出了适合低渗透油藏驱油的超微CO2泡沫发泡方式。结果表明:恒速搅拌发泡模型(6000 r/min)、120目石英砂充填填砂管模型产生的超微CO2泡沫效果最好,泡沫量多且尺寸细腻均匀,泡沫在地层压力条件下尺寸可达6.25~31.26μm,达到超微泡沫尺寸要求;通过低渗透岩心超微CO2泡沫注入性能实验测试,阻力系数为8.32~15.33,驱油效果良好,适合低渗透油藏CO2泡沫驱开发和应用。

In order to enhance the oil recovery in low-permeability oil reservoirs,the optimal preparing method of ultra-micro CO2 foam with low interfacial tension was developed.By comparing two types of constant speed agitation and porous media with five foaming modes,considering different stirring speed rates,the sizes of the packing material and the type of the packing material,the preparation of the superfine CO2 foam was developed,the optimal foaming mode was selected for the ultra-micro CO2 foam suitable for the oil flooding in the low-permeability reservoirs.The results show that the ultra-micro CO2 foams produced by the constant-speed stirring foaming model(6000 r/min)and 120-mesh-quartz-sand filled pipe model have the best effects,with a large number of the foams and fine-uniform sizes.The foams can reach the sizes of 6.25-31.26μm under the formation pressure,which can meet the requirements of the superfine foams.Through the experimental test of the ultra-micro CO2 foam injection performance in the low-permeability core,the resistance coefficient is 8.32-15.33,and the displaced effects are much better,which indicate that the CO2 foam flooding is suitable for the development and application in the low-permeability oil reservoir.