CO_(2)地质封存中储层岩石润湿性测量研究进展

A review of wettability measurement of the reservoir rock in CO_(2) geological storage

多孔介质的润湿性是CO_(2)地质封存过程中的重要参数。基于润湿性测量方法和光学成像技术综述了CO_(2)封存条件下不同尺度的多孔介质润湿性测量技术,并分析了相关润湿现象。目前,岩石润湿性的测量主要分为:实验室尺度的表面润湿性测定、孔隙尺度的内部壁面接触角测定,以及宏观尺度的岩心整体润湿性评价。孔隙结构、矿物组成成分和表面粗糙度是孔隙尺度接触角的关键影响因素,它们会影响多孔介质的混合润湿特性并造成润湿滞后现象。根据不同局部驱替事件(如排水、渗吸)的接触角分布建立了孔隙尺度与连续尺度的岩石润湿性关系。最新研究发现,随着驱替的发展,岩石润湿性在排水和渗吸过程中发生了显著改变,但不同尺度的岩石润湿性的关系及润湿转变机理仍需要进一步研究。

The wettability of porous media is an important parameter in the process of CO_(2) geological storage.Based on the wettability measurements and optical imaging techniques,the wettability measurement techniques of porous media at different scales under CO_(2) storage conditions were reviewed,and the related wettability phenomena were analyzed.At present,the rock wettability measurements are mainly described from the measurement of surface wettability at the laboratory scale,the contact angle at the porous inner surface,and the overall wettability evaluation of core samples at the macro scale.It was shown that the pore structure,mineral composition,and surface roughness were critical factors for the pore-scale contact angle,affecting the mixed wetting characteristics of porous media and causing the wetting hysteresis phenomenon.The relationship between pore-scale and continuum-scale rock wettability was established based on the contact angle distribution in different local displacement events(such as drainage and imbibition).A recent study found that the rock wettability changed significantly during the drainage and imbibition process with the development of the displacement process.However,the correlation between the wettability of rocks at different scales and the mechanism of wettability alternation still need to be further studied.