Huang Pengyu, Shen Luming, Gan Yixiang, Maggi Federico, El-Zein Abbas, Pan Zhejun
School of Civil Engineering , Building J05 , The University of Sydney , Sydney , NSW 2006 , Australia.
CSIRO Energy , Private Bag 10 , Clayton South , VIC 3169 , Australia.
Langmuir. 2019 Apr 16;35(15):5324-5332. doi: 10.1021/acs.langmuir.9b00076. Epub 2019 Mar 21.
The dynamic wetting for the CO-water-silica system occurring in deep reservoirs is complex because of the interactions among multiple phases. This work aims to quantify the contact angle of CO-water flow in the silica channel at six different flow velocities using molecular dynamics. The dynamic contact angle values at different contact line velocities are obtained for the CO-water-silica system. By calculating the rates of the adsorption-desorption process of CO and water molecules on the silica surface using molecular dynamics simulations, it has been found that the results of the dynamic contact angle can be explained by the molecular kinetic theory and predicted from the equilibrium molecular simulations. Moreover, the capillary pressure at different contact line velocities is predicted according to the Young-Laplace equation. The change in contact angles at different velocities is compared with empirical equations in terms of capillary number. The results of this study can help us better understand the dynamic process of the multiphase flow at the nanoscale under realistic reservoir conditions.
由于多相之间的相互作用，深部油藏中发生的CO-水-二氧化硅体系的动态润湿过程较为复杂。本工作旨在利用分子动力学方法量化在六种不同流速下CO-水流经二氧化硅通道时的接触角。获得了CO-水-二氧化硅体系在不同接触线速度下的动态接触角值。通过分子动力学模拟计算CO和水分子在二氧化硅表面的吸附-解吸过程速率，发现动态接触角的结果可用分子动力学理论解释，并可从平衡分子模拟中预测。此外，根据杨-拉普拉斯方程预测了不同接触线速度下的毛细管压力。将不同速度下接触角的变化与基于毛细管数的经验方程进行了比较。本研究结果有助于我们更好地理解实际油藏条件下纳米尺度多相流的动态过程。
