东海丽水凹陷古新统非典型湖相烃源岩及油气特征  

AN ATYPICAL LACUSTRINE SOURCE ROCK AND ITS PETROLEUM CHARACTERISTICS IN THE LISHUI SAG OF THE EAST CHINA SEA

作　　者：陈晓东 蒋一鸣 漆滨汶 于仲坤 CHEN Xiaodong;JIANG Yiming;QI Binwen;YU Zhongkun(CNOOC China Limited-Shanghai,Shanghai 200335,China)

机构地区：[1]中海石油(中国)有限公司上海分公司,上海200335

出　　处：《海洋地质前沿》2021年第4期25-38,共14页Marine Geology Frontiers

基　　金：“十三五”国家科技重大专项“东海深层大型气田勘探评价技术”(2016ZX05027)。

摘　　要：东海陆架盆地丽水凹陷主力烃源岩为古新统月桂峰组湖相泥岩,已发现油气以天然气为主,含少量凝析油,与以原油为主的中国东部典型断陷湖盆存在差异。对月桂峰组湖相泥岩进行了综合评价,发现其存在不能生烃的死碳,烃源岩的热演化成熟度与烃源岩形成石油的转化参数之间存在差异。月桂峰组有机质主要来源于陆源有机质,湖相水生生物来源的比例变化较大。烃源岩地球化学特征与典型湖相烃源岩存在差异。总结了湖盆类型对烃源岩的控制因素以及不同湖盆类型烃源岩形成油气的主要特征,并与月桂峰组湖相泥岩及已发现油气特征进行了对比,表明月桂峰组沉积期发育过补偿和平衡补偿湖盆。月桂峰组泥岩为非典型湖相烃源岩。The lacustrine mudstone of the Yueguifeng Formation of Paleocene is the predominant source rock in the Lishui Sag of the East China Sea. Both natural gas and condensate have been found there. However, it is rather different in hydrocarbon sources with the typical lacustrine rift basins in Eastern China where oil dominates.Comprehensive source rock evaluation on the Yueguifeng shale suggests that there occurs dead carbon to certain proportion, which cannot generate petroleum. In addition, the thermal evolution maturities are not in coupling with the requirement of the conversion index from organic matters to hydrocarbons. The organic matters in Yueguifeng Formation shale are mostly terrestrial in origin, and the percentages of lacustrine aquatic organisms varies. There occur some differences in geochemical characteristics between the Yueguifeng source rocks and the typical lacustrine source rocks. The type of lake-basin have certain control over source rock evolution. Based on the comparison of geochemical characteristics of Yueguifeng source rocks and the petroleum generated in the sag with those of the typical lacustrine source rock and petroleum generated in different lake-type basins, it is found that over compensate and balanced compensate lake basin dominated the Yueguifeng period. And the shales in Yueguifeng Formation are atypical lacustrine source rocks.

关 键 词：非典型湖相烃源岩 古新统月桂峰组 湖盆类型 过补偿 平衡补偿 丽水凹陷 东海 

分 类 号：P744.4[天文地球—海洋科学] P618.13