Abstract Explicit knowledge on the two-phase interface evolution during CO2 dissolving in brine provides accurate predictions on the subsurface behavior of long-term CO2 storage. In this research, the interfacial areas of CO2-unsaturated brine were dynamically measured during multiphase flow using 3D quantitative analyses. The two-phase interfaces during brine imbibition were divided into three terms based on their attributes, i.e., ganglia, cluster and singlet. The evolution terms of the interfaces were interesting, as their fates showed wide evolution patterns due to the diverging effects of the Reynolds number (fluid velocity × length scale/fluid viscosity) and gravity. The brine bypassed the CO2, and the interface evolved with the development of a priority path under a heterogeneity impact. Relying on the approach of the slice-averaged and volumetric measurement, the effects of forces and heterogeneity on the CO2-unsaturated brine interface were evaluated on different directions. Linear regression of the clouded data points exploited the validity of the power-law distribution from number of trapped cluster to frequency of interfacial area, and the max interfacial areas and variance decreased, while the mean interfacial area increased with brine saturation. Slice-averaged CO2-brine interfacial areas normalized by volume or geometric surface area decreased linearly with the brine saturation at different Reynolds numbers.

中文翻译：

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多孔介质中盐水吸收过程中CO2-盐水界面面积的动态演化

摘要 CO2 在盐水中溶解过程中两相界面演化的明确知识为长期 CO2 储存的地下行为提供了准确的预测。在这项研究中，使用 3D 定量分析在多相流过程中动态测量了 CO2 不饱和盐水的界面面积。盐水吸收过程中的两相界面根据其属性分为三项，即神经节、簇和单线态。界面的演化项很有趣，因为由于雷诺数（流体速度×长度尺度/流体粘度）和重力的发散效应，它们的命运显示出广泛的演化模式。盐水绕过 CO2，界面随着异质性影响下优先路径的发展而演变。依靠切片平均和体积测量的方法，在不同方向上评估了力和不均匀性对 CO2-不饱和盐水界面的影响。云数据点的线性回归利用了从圈闭簇数到界面面积频率的幂律分布的有效性，最大界面面积和方差减小，而平均界面面积随着盐水饱和度的增加而增加。在不同雷诺数下，按体积或几何表面积归一化的切片平均 CO2-盐水界面面积随盐水饱和度线性下降。云数据点的线性回归利用了从圈闭簇数到界面面积频率的幂律分布的有效性，最大界面面积和方差减小，而平均界面面积随着盐水饱和度的增加而增加。在不同雷诺数下，按体积或几何表面积归一化的切片平均 CO2-盐水界面面积随盐水饱和度线性下降。云数据点的线性回归利用了从圈闭簇数到界面面积频率的幂律分布的有效性，最大界面面积和方差减小，而平均界面面积随着盐水饱和度的增加而增加。在不同雷诺数下，按体积或几何表面积归一化的切片平均 CO2-盐水界面面积随盐水饱和度线性下降。