Gas flotation is often used during treatment of the oilfield produced water. It relies on the generation of gas bubbles and their attachment to oil drops, for example, by forming an oil film on the surface of a gas bubble. In this paper, we present a microfluidic technique for investigating the attachment of crude oil drops to gas bubbles through the spreading mechanism. The developed method allowed us to systematically study the effect of the oil, water, and gas phases, where the investigated parameter was the amount of oil droplets attached to gas bubbles through spreading. The highest attachment efficiency was observed at low or neutral pH. By reducing the salinity, the electrostatic repulsion increased, which had a negative effect on the attachment. The presence of dissolved components stabilized the oil drops and gas bubbles, which decreased their attachment through spreading. Replacing nitrogen with methane improved the attractive interactions between bubbles and oil droplets, enhancing the attachment of oil. The results confirm the potential of microfluidics in studying bubble–droplet interactions, relevant for industrial processes.

中文翻译：

---

原油小滴附着在气泡上的微流研究

在油田采出水的处理过程中经常使用气浮法。它依赖于气泡的产生及其与油滴的附着，例如，通过在气泡表面上形成油膜来实现。在本文中，我们提出了一种微流体技术，用于研究通过扩散机理将原油滴附着到气泡上的情况。所开发的方法使我们能够系统地研究油，水和气相的影响，其中研究的参数是通过扩散附着在气泡上的油滴量。在低或中性pH下观察到最高的附着效率。通过降低盐度，静电斥力增加，这对附件产生了负面影响。溶解成分的存在稳定了油滴和气泡，通过传播减少了它们的依恋。用甲烷替代氮气可改善气泡与油滴之间的吸引力相互作用，从而增强油的附着力。结果证实了微流体在研究与工业过程相关的气泡与液滴相互作用中的潜力。