It is significant to understand the values and trends of the contact angle of CO2/brine/mineral systems to evaluate and model the sealing performance of CO2 Geo-Sequestration (CGS). It has been reported that the contact angles of the CO2/brine/muscovite systems increase as pressure increases from ambient conditions to reservoir conditions. This trend suggests a decrease in seal integrity. In this paper, we studied its mechanisms and the contributing factors by calculating the Frumkin-Derjaguin equation, which is based on the thermodynamics of the interfacial system. Results show that a decrease of pH is a critical factor for the wettability alteration at a lower pressure range (0.1 MPa to 3.0 MPa). In contrast, the increase of CO2 density and the decrease in the interfacial tension of CO2/brine are significant for the wettability change at a higher pressure range (3.0 MPa to 10.0 MPa). Also, sensitivity analysis shows that the contact angle is sensitive to the interfacial tension of CO2/brine and the coefficients of hydration forces.

中文翻译：

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使用 Frumkin-Derjaguin 方程定量研究 CO2/H2O/白云母系统接触角的影响因素

了解 CO2/盐水/矿物系统的接触角的值和趋势以评估和模拟 CO2 地质封存 (CGS) 的密封性能非常重要。据报道，CO2/盐水/白云母系统的接触角随着压力从环境条件增加到储层条件而增加。这种趋势表明密封完整性下降。在本文中，我们通过计算基于界面系统热力学的 Frumkin-Derjaguin 方程来研究其机理和影响因素。结果表明，在较低压力范围（0.1 MPa 至 3.0 MPa）下，pH 值的降低是润湿性改变的关键因素。相比之下，CO2 密度的增加和 CO2/盐水界面张力的降低对于较高压力范围（3.0 MPa 至 10.0 MPa）下的润湿性变化是显着的。此外，敏感性分析表明，接触角对 CO2/盐水的界面张力和水合力系数敏感。