泡沫封堵能力影响因素实验研究

Experimental study on the factors influencing the blocking ability of foam

按照均匀设计的实验方法进行了12组室内泡沫封堵实验,利用回归分析法,得到了泡沫的阻力因子和残余阻力因子与地层渗透率、气液比、注入量、注入速度和稳泡剂质量浓度5个因素的经验公式。研究结果表明,该公式具有较高的准确性,误差小于13%;渗透率和气液比是影响泡沫封堵能力的最主要因素,随着渗透率和气液比的增加,泡沫的封堵能力均呈现先增加后减小的趋势;泡沫封堵窜流通道的能力较弱,在气液比为1:1时可达到最好的封堵效果;泡沫注入后,岩心中气相饱和度迅速升高,在后续注水阶段,气相饱和度降低,但存在一定幅度的波动,注入6倍孔隙体积的水后,岩心中气相饱和度仍维持在45%左右。

A uniform design method is implemented to study the affecting factors relevant to foam blocking ability in lab.And,two empirical formulae of foam resistance factor and foam residual resistance factor are established with five factors:permeability,gas to liquid ratio,injection volume,injection rate and concentration of foam stabilizer.The results indicate that these formulae have a high accuracy whose error is less than 15%.Permeability and gas to liquid ratio are the most influential factors of foam blocking ability.As the rise of permeability and gas to liquid ratio,the blocking ability is improved first and then reduced.After the injection of foam,gas phase saturation increases rapidly in the core,but decreases in the phase of following water injection accompanying with fluctuation.?When 6 PV water is injected,gas phase saturation can still be kept at 45%.