川东北地区下侏罗统自流井组陆相页岩储层孔隙结构特征

页岩的孔隙结构对页岩气的成藏和富集有着重要的影响。通过对川东北地区下侏罗统自流井组样品的薄片观察、氩离子抛光扫描电子显微镜分析、物性测试、压汞—N₂吸附联合、X衍射全岩分析以及X衍射黏土矿物分析，对该区陆相页岩储层的孔隙结构特征进行了研究。（1）川东北地区自流井组陆相页岩的孔隙形态以平行板状孔和狭缝状孔为主，也发育墨水瓶状孔，页岩比表面积平均4.031 m²/g，总孔体积平均93.88×10^-4 mL/g，微孔隙以介孔（2~50 nm）为主；（2）页岩的比表面积与微孔、介孔孔体积存在正相关性，与大孔孔体积不存在相关性；黏土矿物中的伊—蒙混层、绿泥石与页岩比表面积和微孔孔体积呈正相关；陆相页岩TOC含量对大孔孔体积产生一定影响，与其呈一定程度的正相关；（3）自流井组大安寨段的页岩孔隙结构特征整体近似，东岳庙段依据页岩孔隙结构特征的差异可分为西北部和东南部两块，东南部东岳庙段的孔隙结构与大安寨段相似。

Pore structure of continental shale reservoirs in Lower Jurassic Ziliujing Formation,northeastern Sichuan Basin

The accumulation and enrichment of shale gas were significantly influenced by the pore structure of shales. In this study, thin section observation, Argon ionization-scanning electron microscopy analysis, physical property test, mercury injection-N₂ adsorption combination, X-ray diffraction whole rock analysis and X-ray diffraction clay mineral analysis were carried out to study the pore structure characteristics of continental shale of Lower Jurassic Ziliujing Fromation, northeastern Sichuan Basin. Results showed that:(1) In the Ziliujing Formation of the northeastern Sichuan Basin, the pores were mainly parallel plate and slit ones, and ink bottle pores were also developed. The average value of specific surface area of shale was 4.031 m2·g-1, the average value of total pore volume was 93.88×10-4 mL·g-1, and the micro pores were dominated by meso pores (2-50 nm). (2) The specific surface area of shale is positively correlated with the volume of micro pores and meso pores, but not with the volume of macro pores. In clay minerals, illite-montmorillonite and chlorite are positively correlated with shale specific surface area and micro pore volume. The TOC content of continental shale has a certain influence on the macro pore volume, and has a positive correlation with it to a certain extent. (3) The pore structures of shale are similar in the Da'anzhai section of Ziliujing Formation. According to the difference of shale pore structure, the Dongyuemiao section can be divided into two parts:the northwestern and the southeastern. The Dongyuemiao section in the southeast is similar to the Da'anzhai section in pore structures.