Organic-rich marine-continental transitional shale is widely developed in the Permian Shanxi Formation in the Southern North China Basin. In this study, shale samples from the southern and northern wells of the basin were characterized by X-ray diffraction, high-pressure mercury intrusion porosimetry, low-pressure gas adsorption (N2 and CO2) and argon ion polishing-field emissions scanning electron microscopy. The pore types and structures of shale micropores, mesopores and macropores are qualitatively described; their pore size distribution and volume are quantitatively characterized; and the influencing factors of the pore volume are analyzed. The results show that the marine-continental transitional shale pores exhibit an unbalanced multimodal distribution with four peaks at 0.4–0.8 nm, 2–4 nm, 10–50 nm, and >10 µm. The mesopore volume is dominant, accounting for 40–70% of pores. The mesopores of the samples are slit-shaped pores and ink bottle-shaped pores. Since there is a desorption hysteresis loop on the N2 adsorption-desorption curve, most of them belong to the H4 type, and ye23-8 belongs to the mixed H2 and H4 type according to the IUPAC classification scheme. The slit-shaped pores are mainly interlayer pores and interparticle pores in clays, and the ink bottle-shaped pores are tiny dissolved pores and organic matter pores. Ro has negative correlation with the volumes of the mesopores and macropores, but it does not affect the volume of micropores. TOC has a positive correlation with the macropore and micropore volumes, and it has a negative correlation with mesopore volume. The relative contents of kaolinite and I/S have a positive correlation with the mesopore and macropore volumes. The relative content of illite has a negative correlation with the mesopore and macropore volumes. The relative content of chlorite has a negative correlation with the mesopore volume.

中文翻译：

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华北盆地南部二叠系山西组海陆过渡页岩孔隙特征

华北盆地南部二叠系山西组广泛发育富含有机质海陆过渡页岩。在这项研究中，来自盆地南部和北部井的页岩样品通过 X 射线衍射、高压压汞孔隙率测定法、低压气体吸附（N2 和 CO2）和氩离子抛光场发射扫描电子显微镜进行了表征。 . 定性描述了页岩微孔、介孔和大孔的孔隙类型和结构；定量表征它们的孔径分布和体积；并对孔隙体积的影响因素进行了分析。结果表明，海陆过渡页岩孔隙表现出不平衡的多峰分布，在 0.4-0.8 nm、2-4 nm、10-50 nm 和 >10 µm 处有四个峰。中孔体积占主导地位，占孔隙的 40-70%。样品的介孔为狭缝状孔和墨瓶状孔。由于N2吸附-解吸曲线上存在解吸滞后回线，根据IUPAC分类方案，大部分属于H4型，ye23-8属于H2和H4混合型。狭缝状孔隙主要是粘土中的层间孔和粒间孔，墨瓶状孔是微小的溶解孔和有机质孔。Ro 与中孔和大孔的体积呈负相关，但不影响微孔的体积。TOC与大孔和微孔体积呈正相关，与中孔体积呈负相关。高岭石和 I/S 的相对含量与中孔和大孔体积呈正相关。伊利石的相对含量与中孔和大孔体积呈负相关。绿泥石的相对含量与介孔体积呈负相关。