In view of the shale hydration problem in wellbore stability analysis during drilling in shale formation, a quantitative evaluation method based on CT scanning technology was proposed to research the meso-damage characteristics of shale hydration, and the CT scanning tests for shale samples in stages of shale hydration were conducted. The analysis results of CT images and their gray-level histograms show that the early period of soaking is the main period of meso-damage in shale samples, and as the soaking time increases, the meso-damage propagates slowly;the mark of meso-damage increasing dramatically is that the gray-level histogram of the CT image changes from unimodal style to bimodal style. The visual resolutions of CT images can be improved by the pseudocolor enhancement technique, and the integrity and damage degrees of CT images provide a convenient way for quantitative analysis. The relationship between damage variable and soaking time was obtained based on the segmentations of CT images, which shows that the meso-damage of shale hydration mainly occurs in the early stage of soaking, which is the initial stage and rapid evolution stage of meso-damage, from then on, as the damage variable increases continuously and slowly, the macro-damage of shale sample occurs.%针对页岩地层钻井井壁稳定研究中的页岩水化问题，提出了基于CT扫描技术的页岩水化细观损伤特性定量评价方法，开展了不同水化阶段页岩岩样CT扫描实验，并分析了页岩水化细观损伤特性。对CT扫描图像及其灰度直方图进行分析后发现：浸泡前期是岩样内部产生细观损伤的主要时期，随着浸泡时间的增加，主要发生缓慢的损伤拓展；CT 图像灰度直方图由单峰型变为双峰型是页岩内部损伤急剧增加的标志。通过伪彩色增强技术可以提高 CT图像的视觉分辨率，CT图像完整度和破损度分析有利于定量评价页岩水化细观损伤。对CT图像进行了分割并得到了损伤变量与浸泡时间的关系：页岩水化后的细观损伤主要发生在浸泡前期，这一阶段是细观损伤的起始阶段和快速演化阶段，此后随着损伤变量持续而缓慢的增加，岩样将发生宏观破坏。图9参20
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