高邮凹陷古近系原油成因类型及其油气运聚模式研究

摘要

通过分析苏北盆地东台坳陷高邮凹陷古近系原油的物性及其甾萜类化合物的分布特征,结合凹陷的构造与沉积特征对原油的类型进行划分,并系统分析不同类型原油的来源、分布特征以及相应的油气聚集成藏模式。总体上把该凹陷的原油划分为A和B两类,其中A型原油主要来自阜二段烃源岩,主要分布在深凹带及其斜坡部位;B型原油主要发现在深凹带内及其附近的戴南组和三垛组,以深凹带的成熟阜四段烃源岩为主,仅有少量来自深部位的阜二段烃源岩。斜坡部位的油气主要分布在阜一段—阜三段,来自阜二段烃源岩,属于近源运移特征。深凹带内深部位阜二段烃源岩,可以作为下一步勘探的重点。%By analyzing the types of Paleogene crude oil and its origin of Gaoyou sag,Dongtai depression of Subei basin,combining with characteristics of structure,sediment and distribution of different type crude oils,the authors discussed the crude oil migration-accumulation model in the deep sag and slope zone.Crude oil is divided into two types of A B in which the type A oil came from the second member source rock and the type B occurred in the forth member of Funing formation.There are different crude oil migration-accumulation models in the deep sag and slope zone.In the deep sag and its adjacent zone,oil distributed mainly in Dainan formation and Sanduo formation and came from the forth member mature source rock of Funing formation in deep sag zone.In the slope zone,oil distributed mainly from the first to the third member of Funing formation and came chiefly from the second member mature source rock of the Funing formation in deep sag zone.In the meantime,it is the next step of important exploration field in deep zone of sag whose oil derives principally from the second member source rock.