Understanding wettability of clay minerals is crucial in assessing primary migration of hydrocarbon and evaluating CO₂ storage capacities and containment security. In spite of recent efforts, there is considerable uncertainty of experimental data and theoretical predictions are lacking. We, therefore, developed new correlations to predict the advancing and receding contact angles of three different clay minerals (i.e., montmorillonite, Illite and kaolinite) as a function of gas density. To do so, we first measured clay minerals advancing and receding contact angles for helium, nitrogen, argon and carbon dioxide/brine systems at various pressures (5, 10, 15 and 20 MPa) and a constant temperature of 333 K. The statistical analysis shows that the developed correlations are capable of predicting the contact angles of the three clay minerals with very high accuracy (i.e., R > 0.95, for all the newly developed correlations). We thus conclude that the wettability of these clay minerals can be computed from knowledge of the gas densities, using these new empirical correlations. This work has important implications for improving wettability predictions, and thus reducing risks related to subsurface operations, such as CO₂ storage or hydrocarbon recovery. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd.

中文翻译：

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粘土润湿性对气体密度的依赖性

了解粘土矿物的润湿性对于评估碳氢化合物的初级运移和评估 CO ₂至关重要存储容量和收容安全。尽管最近做出了努力，但实验数据存在相当大的不确定性，并且缺乏理论预测。因此，我们开发了新的相关性来预测作为气体密度函数的三种不同粘土矿物（即蒙脱石、伊利石和高岭石）的前进和后退接触角。为此，我们首先测量了氦气、氮气、氩气和二氧化碳/盐水系统在不同压力（5、10、15 和 20 MPa）和 333 K 恒定温度下的粘土矿物前进和后退接触角。 统计分析表明开发的相关性能够以非常高的准确度预测三种粘土矿物的接触角（即R> 0.95，对于所有新开发的相关性）。因此，我们得出结论，这些粘土矿物的润湿性可以根据气体密度的知识，使用这些新的经验相关性来计算。这项工作对于改进润湿性预测具有重要意义，从而降低与地下操作（例如 CO ₂储存或碳氢化合物采收）相关的风险。© 2021 化学工业协会和 John Wiley & Sons, Ltd.