中文摘要：

渤中凹陷古近系发育三套烃源岩，即始新统沙河街组三段、沙河街组一段以及渐新统东营组烃源岩。前两套烃源岩普遍发育于整个渤海湾盆地，而后一套烃源岩在渤中凹陷最为发育。沙三段烃源岩主要形成于中深湖沉积环境，有机质丰度高、有机质类型好，属于优质烃源岩。沙三段烃源岩展布面积大、厚度大、埋藏深，主体处于成熟一高成熟阶段。沙一段烃源岩为湖盆收缩期半咸水一咸水环境形成的烃源岩，同样具有高的有机质丰度和很好的有机质类型，属于优质烃源岩，但厚度小，烃源岩规模较小。受新构造运动的影响，渤中凹陷沉积了巨厚的东营组地层。东营组三段烃源岩以中深湖相沉积为主，具有较高的有机质丰度和较好的有机质类型，为好一优质烃源岩；东二下亚段与东三段烃源岩相比，有机质丰度降低，有机质类型变差，但主要仍属于中等一好烃源岩。东三段和东二下亚段烃源岩分布广、厚度大，在渤中凹陷主体处于成熟阶段，是本区重要的烃源岩。

英文摘要：

Three source rock horizons occurred in the Bozhong Sag in Bohai Bay Basin： they are the 3nd Member and 1st Member of the Eocene Shahejie Formation and the Dongying Formation. The source rocks of the 3ra Member and the 1stMember of the Shahejie Formation are widely de- veloped in the whole Bohai Bay Basin while the Dongying Formation only appeared in the Bozhong Sag. The source rock of the 3~d Member of the Shahejie Formation deposited in semi-deep to deep lacustrine environment has high amount of organic matter rich in hydrogen, oil-prone kerogen with excellent hydrocarbon potential. In the Bohai Bay Basin, the source rock of the 3rd Member of the Shahejie Formation is characteristic of mature to high mature, widely distributed, deeply buried with large thickness. The 1st Member of the Shahejie Formation formed in brackish to sa- line lakes with high organic matter content and contained type I and type II kerogens. Compared tO source rock of the 3rd Member of the Shahejie Formation,the 1st Member of the Shahejie For- mation is thin and only locally distributed. Constructive effects of neotectonism occurred in the Bozhong Sag and the Dongying Formation resulted in the deposition of thick sediments. The 3rd Member of the I）ongying Formation deposited in semi-deep to deep lacustrine environment has high organic matter content and kerogen. In contrast to the 3rd Member of the Dongying Forma- tion source rock,the low 2nd Member of the Dongying Formation has less organic matter content and contained poor organic matter. The source rocks of the 3rd to the Low 2nd Member of the Dongying Formation widely distribute in Bozhong Sag and are very thick and mainly mature at the peak time of hydrocarbon generation in the Bozhong, so they are the primary source rocks in this Sag.