Department of Chemical and Biomolecular Engineering, Rice University , 6100 Main Street, MS-362, Houston, Texas 77005, United States.
Langmuir. 2018 Jan 23;34(3):739-749. doi: 10.1021/acs.langmuir.7b02766. Epub 2017 Nov 3.
Foam flooding in porous media is of increasing interest due to its numerous applications such as enhanced oil recovery, aquifer remediation, and hydraulic fracturing. However, the mechanisms of oil-foam interactions have yet to be fully understood at the pore level. Here, we present three characteristic zones identified in experiments involving the displacement of crude oil from model porous media via surfactant-stabilized foam, and we describe a series of pore-level dynamics in these zones which were not observed in experiments involving paraffin oil. In the displacement front zone, foam coalesces upon initial contact with crude oil, which is known to destabilize the liquid lamellae of the foam. Directly upstream, a transition zone occurs where surface wettability is altered from oil-wet to water-wet. After this transition takes place, a strong foam bank zone exists where foam is generated within the porous media. We visualized each zone using a microfluidic platform, and we discuss the unique physicochemical phenomena that define each zone. In our analysis, we also provide an updated mechanistic understanding of the "smart rheology" of foam which builds upon simple "phase separation" observations in the literature.
泡沫驱油在多孔介质中越来越受到关注，因为它有许多应用，如提高石油采收率、含水层修复和水力压裂。然而，油-泡沫相互作用的机制在孔隙水平上还没有被完全理解。在这里，我们在涉及通过表面活性剂稳定的泡沫从模型多孔介质中置换原油的实验中确定了三个特征区，并描述了在涉及石蜡油的实验中没有观察到的这些区中的一系列孔隙级动力学。在驱替前缘区，泡沫在与原油最初接触时聚结，这已知会使泡沫的液膜失稳。直接在上游，发生一个过渡区，表面润湿性从油湿变为水湿。在此转变发生后，存在一个强大的泡沫带区，泡沫在多孔介质中生成。我们使用微流控平台可视化了每个区，并讨论了定义每个区的独特物理化学现象。在我们的分析中，我们还提供了对泡沫“智能流变学”的更新的机械理解，该理解建立在文献中简单的“相分离”观察之上。
