东营凹陷东辛油田油源对比研究

东辛油田是渤海湾盆地最大的复杂断块油田,油气来源复杂。以原油和烃源岩饱和烃色谱、色谱质谱分析为基础,将该区原油划分为来自沙三段源岩的“沙三型”和来自沙三、沙四源岩的“混源型”,其中“混源型”占较大优势。结合地质背景和地球化学资料分析,认为该区油气主要来自利津、牛庄和民丰3个洼陷,其中“沙三型”原油主要分布于靠近利津洼陷一侧;“混源型”石油分布广泛,越接近牛庄洼陷,混源油中沙四型原油的贡献越大。研究表明,近洼陷的混源油来自同一洼陷的不同烃源岩,油田中心区块的混源油则为不同洼陷和不同层位原油的混合。多组断裂发育和多洼陷充注是导致该区大量混源石油出现的主要原因。

Research on oil and source rock correlation of Dongxin Oilfield in Dongying depression

As the largest complicated fault-block oilfield of Dongying depression in Bohai Bay basin,Dongxin Oilfield is charged by multiple source rocks.According to the analysis of crude oil and rock's saturated hydrocarbons chromatography,chromatogram-mass spectrometry,oil of Dongxin Oilfield is divided into two types,Es_3 oil from Es_3 source rock and mixture oil from Es_3 and Es_4 source rock,and mixture oil takes the dominant part. Based on an integrated ananlysis of geologic background and geochemical data,it is considered that petroleum in Dongxin area mainly come from Lijin,Niuzhuang and Minfeng sub-sag.Es_3 oil is near Lijin sub-sag,and mixture oil distributes broadly,and the nearer to Niuzhuang sub-sag,the larger of the portion of Es_4 oil is.Mixture oil near sub-sag comes from different formation in identical sub-sag,and mixture oil in the centre location of the interest area comes from different formation in different sub-sag.It is pointed that compound faults and multiple sub-sags oil-offering are the main factors determining oil complicated resource.