Substantial physiochemical changes occur during the interaction between supercritical carbon dioxide (ScCO₂) and shale. It is important to clarify the variation and controlling factors of the microscopic pore structure (MPS). Six samples collected from Longmaxi Formation with various material compositions were treated with ScCO₂. X-ray diffraction (XRD), scanning electron microscope (SEM), gas adsorption, and the maximum adsorption quantity (MAQ) model were employed to determine parameters before and after ScCO₂ treatment. XRD data document feldspar, carbonate, and clay decrease after ScCO₂ treatment. Specifically, the dissolution of clay and carbonate increases the micropore volume and mesopore specific surface area (meso-SSA), respectively. From gas adsorption results, two types based on the difference in total organic content (TOC) are identified, i.e. an accelerating improvement (samples with a TOC less than 3.00 %) and a moderating improvement (samples with a TOC greater than 3.00 %). Data from gas adsorption also support increased MPS parameters with pressure, indicating the variation can be classified into three discernible phases, i.e. a negligible variation at low-pressure, a swift increase at medium-pressure, and a sharp increase at high-pressure. Temperature, however, has a limited improvement on the MPS. These findings are likely to impact the MPS variation in the process of CO₂-enhanced shale gas recovery (CO₂-EGR).

在超临界二氧化碳（ScCO ₂）与页岩之间的相互作用过程中，发生了大量的物理化学变化。阐明微观孔结构（MPS）的变化和控制因素非常重要。用ScCO ₂处理从龙马溪组收集的具有不同材料组成的六个样品。用X射线衍射（XRD），扫描电子显微镜（SEM），气体吸附和最大吸附量（MAQ）模型确定ScCO ₂处理前后的参数。XRD数据记录了ScCO ₂后长石，碳酸盐和粘土的减少治疗。具体而言，粘土和碳酸盐的溶解分别增加了微孔体积和中孔比表面积（meso-SSA）。从气体吸附结果中，可以根据总有机物含量（TOC）的差异确定两种类型，即加速改善（TOC小于3.00％的样品）和适度改善（TOC大于3.00％的样品）。来自气体吸附的数据还支持随压力增加的MPS参数，表明该变化可以分为三个可识别的阶段，即，低压下的变化可忽略不计，中压下的迅速增加，以及高压下的急剧增加。然而，温度对MPS的改善有限。这些发现可能会影响CO ₂过程中MPS的变化-增强页岩气回收率（CO ₂ -EGR）。