【摘要】 系统表征纹层型页岩孔隙结构对于准确认识页岩油富集机理与优选有利甜点区具有关键意义。本研究选取渤海湾盆地黄骅坳陷歧口凹陷沙河街一段（沙一段）纹层型页岩样品，联合CO₂与N₂吸附实验，从纳米至微米尺度揭示其孔隙类型与分形结构特征。结果显示：（1）研究层段TOC为0.83%～6.72%,Ro为0.52%～0.72%，纹层类型主要包括有机质-碳酸盐纹层、富黏土-长英质纹层以及长英质-有机质-碳酸盐复合纹层；（2）孔隙类型以粒间孔、晶间孔、溶蚀孔、有机质孔和纹层微裂缝为主，孔径主要集中在0.3～40 nm，介孔对孔体积贡献最大，微孔和介孔共同控制比表面积；（3） FHH分形分析显示，D₁（2.061 1～2.487 0）主要表征有机质相关微孔吸附界面的表面粗糙度，D₂（2.508 8～2.750 6）主要表征石英-碳酸盐矿物骨架控制的介孔—宏孔孔喉结构复杂度；（4）页岩油甜点评价不能仅依赖TOC或单一孔型参数，而应同时关注高D₁所指示的吸附储集能力与高D₂所指示的渗流连通能力。主控因素分析表明，歧口凹陷沙一段纹层型页岩并非单一“有机孔主导”储集模式，而是表现为有机质微孔吸附体系与矿物骨架孔道体系协同控制的双重孔隙结构。研究成果可为研究区纹层型页岩甜点评价、开发井部署和压裂主攻层段优选提供定量地质参考，也可为其他盆地页岩油的勘探开发地质评价提供思路与方法借鉴。更多还原

【Abstract】 Systematic characterization of the pore structure of laminated shale is essential for accurately understanding shale oil enrichment mechanisms and identifying favorable sweet spots. In this study, laminated shale samples from the first member of the Shahejie Formation（Es₁） in Qikou Sag, Huanghua Depression, Bohai Bay Basin, were investigated, and combined CO₂ and N₂ adsorption experiments were conducted to reveal pore types and fractal structural characteristics from the nanometer to micrometer scale. The results indicate that:（1） TOC is 0. 83% –6. 72%; Ro is 0. 52% –0. 72%, and laminae types mainly include organic matter-carbonate laminae, clay-rich-felsic laminae, and felsic-organic matter-carbonate composite laminae.（2） Pore types are dominated by intergranular pores, intercrystalline pores, dissolution pores, organic matter pores, and laminar microfractures, and pore diameters are mainly concentrated in 0. 3 –40 nm; mesopores contribute the most to pore volume, and micropores and mesopores jointly control specific surface area.（3） FHH fractal analysis indicates that D₁（2. 061 1–2. 487 0） primarily characterizes the surface roughness of organic matter-related micropore adsorption interfaces, and D₂（2. 508 8 – 2. 750 6） mainly represents the complexity of mesopore-macropore throat structures controlled by quartz-carbonate mineral frameworks.（4） The evaluation of shale oil sweet spots should not rely solely on TOC or a single poretype parameter but should simultaneously focus on the adsorption storage capacity indicated by high D₁ and percolation connectivity indicated by high D₂. Analysis of controlling factors indicates that the laminated shale in the Es₁ of Qikou Sag does not exhibit a single “organic pore-dominated” storage model but rather a dual pore structure synergistically controlled by an organic matter micropore adsorption system and a mineral framework pore throat system. The research results provide quantitative geological references for sweet spot evaluation, development well deployment, and optimization of key fracturing intervals in the laminated shale within the study area and offer insights and methodological references for geological evaluation of shale oil exploration and development in other basins.更多还原