渤海湾盆地黄骅坳陷歧北次凹古近系沙河街组三段一亚段页岩含油性控制因素与页岩油富集模式

Controlling factors in oil-bearing properties and shale oil enrichment patterns of the 1st sub-member of the 3rd member of the Paleogene Shahejie Formation， Qibei Sub-sag， Huanghua Depression， Bohai Bay Basin

游祖辉 赵建华 蒲秀刚 刘可禹 张伟 王志昊 时战楠 韩文中 官全胜 王纪扬

Zuhui YOU Jianhua ZHAO Xiugang PU Keyu LIU Wei ZHANG Zhihao WANG Zhannan SHI Wenzhong HAN Quansheng GUAN Jiyang WANG

渤海湾盆地黄骅坳陷歧北次凹古近系沙河街组三段（沙三段）页岩油展现了巨大的勘探开发潜力。通过开展系统的岩心观察、薄片鉴定、扫描电镜、X射线衍射（XRD）、高压压汞、总有机碳含量（）以及岩石热解等实验分析，探讨了页岩油富集的地质条件及控制因素。研究表明：① 歧北次凹沙三段一亚段主要发育纹层状中粒灰云质页岩、纹层状细粒混合质页岩、层状细粒混合质泥岩、层状中粒混合质泥岩、层状粗粒长英质泥岩和块状中粒混合质泥岩6种典型岩相。② 泥/页岩介于0.23 % ~ 2.57 %，有机质类型以Ⅱ型-Ⅲ型为主，沙三段一亚段页岩最高热解峰温（）介于435 ~ 463 ℃，整体处于成熟阶段。③ 主要发育颗粒间孔、晶体间孔、黏土矿片间孔、粒内溶蚀孔、有机质孔和微裂缝6种类型的储集空间。页岩油主要赋存于小孔喉的黏土矿片间孔、溶蚀孔和大孔喉的晶体间孔、微裂缝中。④ 有机质含量、有机质类型、储层类型和沉积构造耦合构成的微观“源-储”组合是歧北次凹沙三段一亚段页岩油富集的主控因素。⑤ 纹层状中粒灰云质页岩、纹层状细粒混合质页岩和层状细粒混合质泥岩具备良好的源-储组合关系，是研究区页岩油富集的有利岩相类型。

The 3rd member of the Shahejie Formation （E） in the Qibei Sub-sag， Huanghua Depression， Bohai Bay Basin holds enormous potential for shale oil exploration and exploitation. Using systematic experiments and analyses including core and thin section observations， scanning electron microscopy （SEM）， X-ray diffraction （XRD）， high-pressure mercury injection， total organic carbon （） content analysis， and rock pyrolysis analysis， we explore the geological conditions and controlling factors for shale oil enrichment in the E. Six typical lithofacies of the E are identified： laminated medium-grained calcareous-dolomitic shale， laminated fine-grained mixed shale， lamellar fine-grained mixed mudstone， lamellar medium-grained mixed mudstone， lamellar coarse-grained felsic mudstone， and massive medium-grained mixed mudstone. These mudstones/shales exhibit a content ranging from 0.23 % to 2.57 %， with organic matter dominated by Types Ⅱ to Type Ⅲ kerogen. The E shales display peak pyrolysis temperatures （） varying from 435 ℃ to 463 ℃， indicating that these shales are generally in the mature stage of thermal evolution. Major reservoir space types identified in the study area include intergranular pores， intercrystalline pores， inter-clay-flake pores， intragranular dissolution pores， organic pores，and microfractures. Shale oil predominantly occurs in inter-clay-flake and dissolution pores with small pore-throats， as well as intercrystalline pores and microfractures， both with large pore throats. Major factors controlling shale oil enrichment in the E include content， organic matter type， reservoir type， and sedimentary structures， which together form microscopic source rock-reservoir assemblages. Among the various lithofacies， the laminated medium-grained calcareous-dolomitic shale， laminated fine-grained mixed shale， and the lamellar fine-grained mixed mudstone exhibit effective source rock-reservoir assemblages， establishing themselves as favorable lithofacies for shale oil enrichment in the study area.

10.11743/ogg20250208