我国煤储层存在“三高一低”的特点，煤的孔隙结构特征是影响渗透率和排采难易程度及后续排采方式的重要因素。为了精确表征煤的全尺度孔径结构，采用高压压汞、低温液氮及二氧化碳吸附3种方法，在对高压压汞试验数据进行压缩性校正的基础上，结合分形理论，分析不同试验方法优势孔径表征区段，实现对云南老厂矿区10组煤样的全尺度孔径联合表征。结果表明：煤基质压缩系数在7.06179×10⁻¹¹～1.23531×10⁻¹⁰ m²/N，校正后的累计进汞量比校正前的减少15.89%～27.82%，平均为21.65%，煤基质在注汞压力达到0.7 MPa时开始受到压缩，注汞压力达到14.3 MPa时受到不可逆破坏。液氮吸附试验中阶段孔体积整体上随着孔径增大而逐渐增大，微孔区段趋于稳定且吸附体积较小，微孔吸附速率最快，整体随着孔径增大，速率减小，吸附曲线类型为Ⅳ型，迟滞环类型为H3、H4型。二氧化碳吸附试验阶段吸附体积曲线与微分曲线基本一致，孔隙体积整体随着孔径的增大而减小。压汞分形曲线可划分为3段，当$ text{lg}{{P}}_{{i}} $>1.1时，分维值达到最大，煤基质受到不可逆的压缩破坏。低温液氮吸附分形曲线以相对压力$ {{P}}_{rm{j}}text{/}{{P}}_{rm{s}} $=0.5为界线，表征2～5 nm孔径的分维值为1.93～2.92，平均为2.57；表征5～100 nm孔径的分维值为2.16～2.76，平均为2.49，微孔非均质性较强。综合3种试验结果，以1.5和100 nm为拼接点，煤样中以孔径0.41～0.86 nm间的微孔为主，孔隙体积占比最大。

Chinese coal reservoirs are characterized by “Three High and One Low”, and the pore structure of coal is an important factor affecting the permeability, the degree of drainage difficulty and the subsequent drainage mode. In order to accurately characterize the full scale pore size structure of coal, three methods of high pressure mercury injection, low temperature liquid nitrogen and carbon dioxide adsorption are used. Based on the compressibility correction of the high pressure mercury injection experimental data, combined with the fractal theory, the dominant pore size characterization sections of different experimental methods are analyzed, and the full scale joint characterization of 10 groups of coal samples in Yunnan Laochang mining area is realized. The results show that: The compression coefficient of coal matrix ranges from 7.06179×10⁻¹¹ to 1.23531×10⁻¹⁰ m²/N, and the cumulative mercury intake after correction is reduced by 15.89% ～ 27.82% compared with that before correction, with an average of 21.65%. The coal matrix begins to be compressed when the mercury injection pressure reaches 0.7 MPa. Irreversible damage occurs when the mercury injection pressure reaches 14.3 MPa. In the liquid nitrogen adsorption experiment, the pore volume increases gradually with the increase of the pore size on the whole, the pore area tends to be stable and the adsorption volume is small, and the pore adsorption rate is the fastest. The overall rate decreases with the increase of the pore size. The adsorption volume curve and differential curve of carbon dioxide adsorption experiment stage are basically consistent, and the pore volume decreases with the increase of pore size. The mercury injection fractal curve can be divided into three sections. When lgP_i > 1.1, the fractal dimension reaches the maximum, and the coal matrix suffers irreversible compression failure. The low temperature liquid nitrogen adsorption fractal curve takes P_j/P_s =0.5 as the boundary line. The fractal dimension of 2−5 nm pore size is between 1.93−2.92, with an average value of 2.57. The fractal dimension of 5−100 nm pore diameter is 2.16−2.76, with an average value of 2.49, indicating strong heterogeneity. Based on the three experimental results, with 1.5nm and 100nm as the splicing points, the coal samples are dominated by micropores with pore sizes ranging from 0.41nm to 0.86nm, with the largest proportion of pore volume.