Overmature continental shale is commonly developed, but few studies have given insight into its pore structure and sorption capacity. Various techniques, including SEM, helium porosity and permeability, N₂/CO₂ adsorption, MICP, and NMR, were used to detect the pore structure of shale from the Shahezi Formation, Xujiaweizi Fault, Songliao Basin. The excess methane adsorption volumes were measured by the volumetric method and modeled by the Langmuir model. Based on the findings, the most developed pores are intraparticle pores in clay minerals, followed by the dissolution pores in feldspar, but organic pores are uncommon. The selected shales have low helium porosity (mean 1.66%) and ultralow permeability (mean 0.0498 × 10⁻³µm²). The pore throats are at the nanoscale, and the pore-throat size distributions are unimodal, with most less than 50 nm. The studied shales are characterized by the lower specific surface area (SSA) and pore volume (PV) but the larger average pore diameter. The total SSA is contributed by the micro- and mesopores, while the PV is dominated by meso- and macropores. The pore structures are more complex and controlled by multiple factors, such as mineral compositions and diagenesis, but organic matter is not critical. The maximum absolute adsorption methane volume (V_L) is 0.97–3.58 cm³/g (mean 1.90 cm³/g), correlating well with the total SSA, SSA, and pore volume of micropores, which indicates that methane is mainly adsorbed and stored in micropores, followed by mesopores.

过成熟的陆相页岩普遍发育，但对其孔隙结构和吸附能力的研究很少。采用SEM、氦孔渗率、N ₂ /CO ₂吸附、MICP、NMR等技术对松辽盆地徐家围子断裂沙河子组页岩孔隙结构进行了检测。过量甲烷吸附体积通过容量法测量并通过朗缪尔模型建模。研究发现，粘土矿物中的粒内孔最为发育，其次是长石中的溶蚀孔，但有机质孔并不常见。所选页岩具有低氦孔隙度（平均1.66%）和超低渗透率（平均0.0498 × 10 ^-3 µm ²）。孔喉处于纳米尺度，孔喉尺寸分布呈单峰分布，大部分小于50 nm。研究的页岩的特点是比表面积（SSA）和孔隙体积（PV）较低，但平均孔径较大。总SSA由微孔和中孔贡献，而PV由中孔和大孔主导。孔隙结构更加复杂，受矿物成分和成岩作用等多种因素控制，但有机质并不重要。最大绝对甲烷吸附体积（V _L）为0.97~3.58 cm ³ /g（平均1.90 cm ³ /g），与总SSA、SSA和微孔孔容相关性较好，表明甲烷主要被吸附和吸附。储存在微孔中，其次是中孔。