Abstract: Considering the special nature of CO₂ and the behavior of CO₂ foam in the porous medium different from foams of other gases, CO₂ foam stability, decay property of CO₂ foam and effect of partially hydrolyzed polyacrylamide (HPAM) on CO₂ foam properties were studied. The gas-flow method was used for foaming and sodium dodecyl benzene sulfonate (SDBS) was used as the foaming agent. The stability of CO₂ foam was worse than that of N₂ foam under the same conditions and was nearly not influenced by surfactant concentration. Besides, the decay curve of CO₂ foam was approximately a straight line and the volume of CO₂ foam decreased rapidly after foaming. An important factor leading to the poor stability of CO₂ foam lay on the large film permeability coefficient because of higher solubility of CO₂ in water, which further led to the different propagation behavior of CO₂ foam from N₂ foam in the core. The adding of polymer HPAM enhanced the stability of CO₂ foam to a certain extent, but reduced the foaming property of surfactant solution. Therefore, both foam stability and foaming property of surfactant solution should be considered to determine the optimal concentration of polymer in the actual application.

Key words: carbon dioxide, foam, surfactants, polymers, foam film permeability

摘要： 基于CO₂气体性质的特殊性以及CO₂泡沫在多孔介质中表现出不同于其他气体泡沫的现象，利用气流法，选用十二烷基苯磺酸钠（SDBS）作为起泡剂，研究了CO₂泡沫的稳定性和衰减规律，以及聚合物部分水解聚丙烯酰胺（HPAM）对CO₂泡沫性能的影响。结果表明，在相同条件下，CO₂泡沫的稳定性比N₂泡沫差，并且CO₂泡沫的稳定性基本不受表面活性剂浓度的影响；CO₂泡沫的衰减曲线近似一条直线，泡沫形成后体积迅速减小。CO₂在水中具有较大的溶解度，泡沫的液膜渗透率系数大，因而泡沫稳定性差，也是造成CO₂泡沫在岩心内渗流规律区别于N₂泡沫的一个重要原因。HPAM的加入可以在一定程度上增强CO₂泡沫的稳定性，但同时也会使溶液起泡性能降低，所以实际应用时需要综合考虑泡沫特性，选择最佳的聚合物浓度。

关键词: 二氧化碳, 泡沫, 表面活性剂, 聚合物, 液膜渗透率