Abstract: The proved rate of conventional crude oil in Qintong sag of Subei Basin is more than 40%, and resource replacement is facing great challenges. Compared with other basins in China, Qintong sag is characterized as being fragmented, small, poor, and deep. The mud shale in Qintong sag has a low abundance of organic matter, in which the total organic carbon (TOC) content is generally lower than 1.5%. In recent years, by strengthening the basic geological research of accumulation, the main controlling factors of shale oil accumulation have been identified, including special organic maceral types, favorable lithofacies association, complex three-dimensional pore-fracture system, good preservation conditions and good transformability. The dynamic accumulation model of shale oil in Qintong sag of Subei Basin has been established, and the evaluation index of the sweet spot of continental shale oil with low TOC content has been established, which has laid a theoretical foundation for the exploration and development of shale oil. Through the deployment and implementation of risk exploration wells, Well SD1 obtained the highest test oil production of 50.9 t/d and the cumulative flowing oil production of 1.5×10⁴t, making a great breakthrough in the exploration of continental shale oil in Subei Basin, and showing a good prospect of shale oil exploration and development in Member 2 of Funing Formation. According to the resource evaluation results, the favorable area of shale oil in Member 2 of Funing Formation of Qintong sag is 420 km², and possess the resources of 2.95×10⁸t. The breakthrough of shale oil exploration in Qintong sag has changed the evaluation criteria of continental shale oil in China, and boosted the confidence of increasing reserves and production of shale oil in small continental basins of eastern China, which is of important theoretical and practical significance.

Key words: lithofacies association, low TOC content, enrichment and high yield, Member 2 of Funing Formation, Qintong sag, Subei Basin

摘要： 苏北盆地溱潼凹陷常规原油的探明率超过40%，资源接替面临较大挑战。与中国其他盆地相比，溱潼凹陷具有"碎、小、贫、深"的特点，其内泥页岩的有机质丰度低，总有机碳（TOC）含量普遍低于1.5%。近年来，通过深化成藏基础地质研究，初步明确了页岩油成藏的主控因素，包括特殊的有机显微组分类型、有利的岩相组合、复杂的立体孔缝系统、良好的保存条件和较好的可改造性，建立了苏北盆地溱潼凹陷页岩油动态成藏模式，建立了低TOC含量陆相页岩油"甜点"评价指标，为页岩油的勘探开发奠定了理论基础。通过部署实施风险探井，SD1井测试获得最高产油量50.9 t/d，自喷累计产油量为1.5×10⁴t，实现了苏北盆地陆相页岩油勘探的重大突破，展现出阜宁组二段（阜二段）页岩油良好的勘探开发前景。资源评价结果认为，溱潼凹陷阜二段页岩油的有利区面积为420 km²，资源量为2.95×10⁸t。溱潼凹陷页岩油的勘探突破改变了中国陆相页岩油的评价标准，提振了中国东部小型陆相盆地页岩油增储建产的信心，具有重要的理论和现实意义。

关键词: 岩相组合, 低TOC含量, 富集高产, 阜宁组二段, 溱潼凹陷, 苏北盆地