The lithology, lithofacies, reservoir properties and shale oil enrichment model of the fine-grained sedimentary system in a lake basin with terrigenous clastics of large depression are studied taking the organic-rich shale in the first member of Cretaceous Qingshankou Formation (shortened as Qing 1 Member) in the Changling Sag, southern Songliao Basin as an example. A comprehensive analysis of mineralogy, thin section, test, log and drilling geologic data shows that lamellar shale with high TOC content of semi-deep lake to deep lake facies has higher hydrocarbon generation potential than the massive mudstone facies with medium TOC content, and has bedding-parallel fractures acting as effective reservoir space under over pressure. The sedimentary environments changing periodically and the undercurrent transport deposits in the outer delta front give rise to laminated shale area. The laminated shale with medium TOC content has higher hydrocarbon generation potential than the laminated shale with low TOC content, and the generated oil migrates a short distance to the sandy laminae to retain and accumulate in situ. Ultra-low permeability massive mudstone facies as the top and bottom seals, good preservation conditions, high pressure coefficient, and lamellar shale facies with high TOC are the conditions for “lamellation type” shale oil enrichment in some sequences and zones. The sequence and zone with laminated shale of medium TOC content in oil window and with micro-migration of expelled hydrocarbon are the condition for the enrichment of “lamination type” shale oil. The tight oil and “lamination type” shale oil are in contiguous distribution.

以白垩系青山口组一段富有机质页岩为研究对象，研究大坳陷陆源碎屑湖盆细粒沉积体系的岩性、岩相、储层性质及页岩油富集模式（简称青1员）以松辽盆地南部长岭凹陷为例。矿物学、薄片、试验、测井和钻井地质资料综合分析表明，半深湖至深湖相高TOC含量的层状页岩比中等TOC含量的块状泥岩相具有更高的生烃潜力，具有较高的生烃潜力。层理平行裂缝作为超压下的有效储层空间。周期性变化的沉积环境和外三角洲前缘的暗流输送沉积形成了层状页岩区。中 TOC 含量的层状页岩比低 TOC 含量的层状页岩具有更高的生烃潜力，并且生成的油向砂质层状体短距离运移，在原位保留和聚集。超低渗透块状泥岩相作为顶、底封层，保存条件好，压力系数高，层状页岩相 TOC 高，是部分层序和带“层状”页岩油富集的条件。油窗中TOC含量中等的层状页岩层序和带被排烃微运移，是“层状”页岩油富集的条件。