超临界CO2地质封存是全球减排的重要战略性技术之一。岩石表面润湿性是CO2地质封存过程中一个至关重要的参数，直接影响毛细压、相对渗透率、孔隙空间内各相的分布，进而影响CO2在深部咸水层中的运移规律，最终影响封存效果。超临界CO2粘滞现象显著改变润湿角，但CO2粘滞特性及机理尚不明确。本项目以咸水层封存条件下超临界CO2在岩石表面的粘滞特性及机理为研究对象，采用实验方法获取不同封存环境下超临界CO2的粘滞特性，建立分子动力学模拟模型，探究岩石表面液膜厚度的变化规律及润湿性与液膜厚度的相依关系，建立CO2在岩石表面的粘滞模型，结合液膜厚度及润湿性变化与体系微观结构及分子间相互作用力变化之间的相互关系，阐明超临界CO2的粘滞机理。本项目的顺利完成能为解决多重物理、化学作用的CO2动态运移规律和封存机理这一关键科学问题提供理论和数据积累，为最终实现规模化咸水层CO2封存提供知识储备。

CO2 geologic sequestration is one of the major strategical technologies to decrease anthropogenic CO2 emissions. Wettability of CO2/brine/mineral systems is a very important parameter in supercritical CO2 geologic sequestration. It directly affects several important parameters such as capillary pressure, relative permeability and space distribution of CO2 and brine phases which can affect the migration law of supercritical CO2 in saline aquifers and the sequestration efficiency. It has been found that CO2 adhesion on mineral surfaces greatly changes wettability.However, the characteristics and mechanism of CO2 adhesion are open to questions. The objective of this proposal is to investigate the characteristics and mechanism of CO2 adhesion in saline aquifers. Experimental methods will be used to capture supercitical CO2 adhesion features under different sequestration conditions. Molecular dynamics simulation models will be constructed to investigate the laws of film thickness variation on mineral surfaces as well as the relationship between film thickness and wettability. Coupling with the experimental and molecular dynamics simulation results, a model of supercritical CO2 adhesion will be proposed. Then, the molecular structure of CO2/brine/mineral systems and the forces between molecules will be analyzed during film thickness and wettability variations to explore the mechanism of CO2 adhesion. This project will accumulate theoretical models and useful data to help to solve the key scientific problem of CO2 dynamic migration law and sequestration mechanisms and provide useful knowledge for large scale storage of CO2 in saline aquifers.