为探究页岩矿物组分、孔隙结构及其分形维数对页岩吸附特性的影响，开展龙马溪组、五峰组以及延长组页岩总有机碳（TOC）含量测试、X射线衍射（XRD）测试、低温N2吸附测试，CH4等温吸附实验，基于吸附相体积Va恒定、吸附相密度ρa恒定2种方法对页岩气绝对吸附量进行了校正，并采用Langmuir模型对绝对吸附量进行了拟合，在此基础上获得了页岩矿物组分、孔隙结构以及Langmuir模型参数之间的关系。结果表明：Langmuir模型能很好地拟合实验条件下CH4在不同页岩上的吸附数据，且Langmuir模型对基于Va恒定方法得到的页岩气绝对吸附量拟合结果精度更高。Langmuir体积VL与页岩TOC、石英含量、比表面积、孔体积均呈正相关关系，与平均孔径呈负相关关系，与黏土矿物相关性较差；页岩孔隙结构分形维数D与其TOC含量、石英矿物含量、比表面积、孔体积呈正相关关系，与平均孔径呈负相关关系，与黏土矿物相关性较差；分形维数D与VL呈正相关关系，与Langmuir压力PL呈负相关关系，表明分形维数越大，页岩吸附能力越强。

In this study, the total organic carbon (TOC) content analysis, X-ray diffraction (XRD) tests, low-temperature N2 adsorption tests and CH4 isothermal adsorption tests were carried out on the shale samples from Longmaxi, Wufeng and Yanchang formations, to obtain the relationship between the mineral composition, pore structure and its fractal dimension on adsorption characteristics of shale. Based on the two calculation methods, including the hypothesis of constant adsorbed phase volume Va and constant adsorbed phase density ρa, the absolute adsorption amount of shale gas was corrected and was fitted by Langmuir model, then the relationships between shale mineral composition, pore structure and Langmuir model parameters were obtained. The results show that the Langmuir model can fit well with the adsorption data of CH4 on different shales under the experimental conditions, and the Langmuir model has higher accuracy in fitting the absolute adsorption amount of shale gas obtained based on the hypothesis ofadsorbed phase volume Va Langmuir volume VL is positively correlated with TOC and quartz content, specific surface area and pore volume, and is negatively correlated with the average pore diameter, and poorly correlated with clay minerals. The fractal dimension D of pore structure in shale is positively correlated with TOC content, quartz content, specific surface area and pore volume, and is negatively correlated with average pore diameter, and poorly correlated with clay minerals. The fractal dimension D is positively correlated with VL, and negatively correlated with Langmuir pressure PL, indicating that a larger fractal dimension D correspond stronger adsorption capacity of shale.