Carbon dioxide enhanced oil recovery is an interim solution as the world transitions to a cleaner energy future, extending oil production from existing fields whilst also sequestering carbon dioxide. To make this process efficient, the gas and oil need to develop miscibility over a period of time through the exchange of chemical components between the two phases, termed multiple-contact miscibility. Currently, measurements to infer the development of multiple-contact miscibility are limited to macroscopic visualization. We present a “rock-on-a-chip” measurement system that offers several potential measurements for different wetting conditions to infer the onset of multiple-contact miscibility. Here, a two-dimensional microfluidic porous medium with a stochastic distribution of pillars was created, and an analogue ternary system was used to mimic the real oil and gas multiple-contact miscibility process. Experiments were performed in two directions, imbibition and drainage, permitting study of different wetting properties of the host rock. The distinct behavior of trapped non-wetting ganglia during imbibition and the evolution of phase interfaces during drainage were observed and analyzed as the system developed miscibility. We show how these observations can be converted into rapid measurements for identifying the development of miscibility.

中文翻译：

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微流控芯片中的孔尺度多触点混溶性测量。

随着世界过渡到更清洁的能源未来，二氧化碳提高石油采收率是一个临时解决方案，既可以扩大现有油田的石油产量，又可以隔离二氧化碳。为了使该过程高效，天然气和石油需要在一段时间内通过两相之间化学成分的交换来发展混溶性，这被称为多触点混溶性。当前，用以推断多触点混溶性发展的测量仅限于宏观可视化。我们提供了一种“芯片上的岩石”测量系统，该系统可针对不同的润湿条件提供多种潜在测量结果，以推断多触点混溶的开始。在这里，创建了具有随机分布的支柱的二维微流体多孔介质，并使用模拟三元系统来模拟真实的油气多触点混溶过程。实验在两个方向上进行，即吸水和排水，可以研究基质岩石的不同润湿特性。随着系统发展的可混溶性，观察和分析了在吸收过程中被困的非润湿神经节的独特行为和在排水过程中相界面的演变。我们展示了如何将这些观察结果转换为快速测量结果，以识别混溶性的发展。随着系统发展的可混溶性，观察和分析了在吸收过程中被困的非润湿神经节的独特行为和在排水过程中相界面的演变。我们展示了如何将这些观察结果转换为快速测量结果，以识别混溶性的发展。随着系统发展的可混溶性，观察和分析了在吸收过程中被困的非润湿神经节的独特行为和在排水过程中相界面的演变。我们展示了如何将这些观察结果转换为快速测量结果，以识别混溶性的发展。