Foam is used in CO₂-enhanced oil recovery due to its potential high benefits in mitigating all three causes of CO₂ poor sweep efficiency, as it provides a means to lower the effect of permeability heterogeneity, overcome viscous instability, and minimize the occurrence of gravity override. The conventional foaming surfactants are not suitable in contact with oil due to premature lamellae rupture, need for copious amounts of water to generate foam, surfactant loss due to adsorption on the rock or partitioning between water and oil, and less tolerance against salinity, pressure, and temperature. The surfactant blending and addition of CO₂-philic functionalities in surfactant structure are suggested to mitigate the above problems, enhance foam stability, improve mobility control, and accelerate foam propagation. However, there is a lack of general guidelines on the evaluation of CO₂-philic surfactant properties and applications and the surfactant structure–performance analysis. In the present work, tailor-made laboratory tests and simulation analysis were conducted on CO₂-philic surfactants with different structures and chain lengths in conditions close to a Malaysian reservoir case and in the presence of oil. The results from experiments combined with analytical analysis of foam flow parameters are used to provide a comprehensive simulation model of a CO₂-philic surfactant alternating gas process. A meaningful correlation between the CO₂-philic surfactant structure and the sensitivity of foam model to different parameters was observed. On the basis of sensitivity analysis results, optimization of CO₂-philic surfactant activity at gas–water and oil–water interfaces can improve the system recovery through macroscopic and microscopic displacement.

中文翻译：

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CO _2-泡沫辅助CO _2-强化采油的综合性能分析

泡沫可用于减轻CO ₂吹扫效率的所有三种原因，因此具有潜在的高效益，可用于提高CO _2的采油率，因为泡沫可降低渗透性非均质性的影响，克服粘性不稳定性并最大程度地减少泡沫的发生。重力优先。常规的发泡表面活性剂由于片层过早破裂，需要大量的水来产生泡沫，由于吸附在岩石上或在水和油之间分配而导致的表面活性剂流失，以及对盐分，压力，和温度。表面活性剂的共混和CO _2的添加建议使用表面活性剂结构中的亲电官能团来减轻上述问题，增强泡沫稳定性，改善流动性控制并加速泡沫传播。但是，在评估亲CO ₂表面活性剂性能和应用以及表面活性剂结构性能分析方面缺乏通用指导原则。在目前的工作中，在接近马来西亚储层的情况下，在有油的情况下，对具有不同结构和链长的亲CO ₂表面活性剂进行了量身定制的实验室测试和模拟分析。实验结果与泡沫流动参数的分析分析相结合，可用于提供CO ₂的综合模拟模型-亲液表面活性剂交替气工艺。观察到CO _2-亲液表面活性剂结构与泡沫模型对不同参数的敏感性之间的有意义的相关性。根据敏感性分析结果，优化气水和油水界面处的CO _2-亲和性表面活性剂可以通过宏观和微观位移来改善系统的采收率。