Abstract: Continental lacustrine shale developed in the Lower Jurassic of Sichuan Basin has high-quality source rock, high-abundance organic matter, and rich shale oil resources. Previous studies mainly focused on the Da'anzhai Member of Ziliujing Formation, and less on other horizons. The geological characteristics and resource potential of lacustrine shale oil in the Lower Jurassic were determined by analyzing the geochemical characteristics of Jurassic shale such as depositional environment, organic matter abundance, type, and maturity, as well as the geological conditions such as shale reservoir properties and reservoir space types. The results show that for the three sets of lacustrine shales in Dongyuemiao Member and Da'anzhai Member of Ziliujing Formation and Lianggaoshan Formation developed in Sichuan Basin, TOC content is generally greater than 1.0%; the organic matter of type Ⅱ₁-Ⅱ₂ indicate that these three sets of shale have good hydrocarbon potential; R_o is within the range of 1.00% to 1.82%, indicating a medium to high degree of thermal evolution. The shale is thick and widely distributed, with an average porosity of 4% -9% and the development of shale bedding fractures. Dongyuemiao Member has a gentle broad basin still-water deposit environment; Da'anzhai Member was formed in the largest lake flooding period in the Jurassic System, shown as a deep basin deep-water environment; Lianggaoshan Formation is dominated by a broad basin shallow-water environment. There are three combination patterns of shale development:pure shale type, shale-carbonate rock interbedding type and shale-sandstone interbedding type. Based on the evaluation of enriched intervals, five sweet spots are clearly divided vertically and the zones of thin oil, light oil and condensate oil and gas are divided horizontally. In particular, major discoveries such as Well Ping'an 1 have demonstrated that there is great exploration and development potential for shale oil in the Jurassic System of Sichuan Basin.

Key words: Sichuan Basin, shale oil, geological characteristics, major discovery, resource potential

摘要： 四川盆地下侏罗统发育陆相湖盆页岩，烃源岩品质好、有机质丰度高、页岩油资源丰富，以往研究主要关注自流井组大安寨段，其他层位研究较少。通过分析侏罗系页岩沉积环境、有机质丰度、类型、成熟度等地球化学特征，以及页岩储集性能、储集空间类型等地质条件，明确了下侏罗统湖相页岩油的地质特征及资源潜力。结果表明：四川盆地发育自流井组东岳庙段、大安寨段和凉高山组3套湖相页岩，页岩TOC含量一般大于1.0%；有机质类型为Ⅱ₁—Ⅱ₂型，3套页岩均具有较好的生烃潜力；R_o值为1.00%~1.82%，热演化程度为中等偏高。页岩厚度大、分布面积广，页岩平均孔隙度为4%~9%，页理缝发育。东岳庙段为平缓的广盆静水沉积环境；大安寨段为侏罗系最大湖泛期沉积，表现为深盆深水环境；凉高山组为广盆浅水环境。页岩发育纯页岩型、页岩-碳酸盐岩互层型、页岩-砂岩互层型3种组合样式。通过对页岩油富集层段进行评价，明确纵向上划分5个甜点段，平面上划分稀油区、轻质油区和凝析油气区3个区带。特别是平安1井等的重大发现，证实了四川盆地侏罗系具备良好的页岩油勘探开发潜力。

关键词: 四川盆地, 页岩油, 地质特征, 重大发现, 资源潜力