Abstract In order to establish the distribution pattern of fine-grained sedimentary rocks and clarify the coupling relationship between lacustrine organic-rich fine-grained sedimentary rocks and tight oil reservoir, the Chang7 Member of Triassic Yanchang Formation in Longdong area was taken as an example to be studied by core description and log interpretation, gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Lacustrine organic-rich fine-grained sedimentary rocks were divided into shale and mudstone according to their lithology and texture. The results show that the shale is mainly developed in Chang73 Sub-member, while the mudstone is developed in each sub-member of Chang7 Member. The organic-rich fine-grained sedimentary rocks in Bazhu-Maling-Qingcheng-Huachi area are the thickest in Longdong area. During the Chang73 sedimentary period, the shale was widely distributed in the center of the lake. In the Chang72 sedimentary period, the mudstone and turbidite were interstratified and superimposed. During the Chang71 sedimentary period, the mudstone was only distributed as thin layers between the thick turbidite. The Chang7 tight oil is widely distributed in the turbidite sand bodies, and it is mainly sourced from the Chang73 shale. The distribution of tight oil is controlled by the development of organic-rich fine-grained sedimentary rocks.

中文翻译：

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湖相富有机质细粒沉积岩对致密油成藏的影响

摘要 为建立细粒沉积岩的分布格局，明确湖相富有机质细粒沉积岩与致密油储层的耦合关系，以陇东地区三叠系延长组长7段为例，通过岩心描述和测井解释、气相色谱 (GC) 和气相色谱-质谱 (GC-MS) 进行研究。湖相富含有机质细粒沉积岩按其岩性和质地分为页岩和泥岩。结果表明，长73亚段主要发育页岩，长7段各亚段发育泥岩。八柱—马岭—青城—华池地区富含有机质的细粒沉积岩以陇东地区最厚。长73沉积期页岩广泛分布于湖心。长72沉积期泥岩与浊积岩层间叠置。长71沉积期泥岩仅以薄层分布于厚浊积岩之间。长7致密油广泛分布于浊积砂体中，主要来源于长73页岩。致密油分布受富含有机质细粒沉积岩的发育控制。长7致密油广泛分布于浊积砂体中，主要来源于长73页岩。致密油分布受富含有机质细粒沉积岩的发育控制。长7致密油广泛分布于浊积砂体中，主要来源于长73页岩。致密油分布受富含有机质细粒沉积岩的发育控制。