东营凹陷中央洼陷带沙三段高分辨率层序地层与岩性圈闭特征

对东营凹陷中央洼陷带的钻井和三维地震资料进行了综合解释和分析,研究了东营凹陷中央洼陷带沙三段高分辨率层序地层格架。研究结果表明,东营凹陷三角洲主要发育层段———沙三中亚段可以划分为6个短期基准面旋回,每个短期基准面旋回包含着多个次级基准面升降旋回。岩性圈闭主要由浊积成因的砂体组成,可将其划分为滑塌浊积岩、坡移浊积扇和湖底扇圈闭3种类型,每种圈闭类型的形成和分布都与基准面的升降变化密切相关。湖底扇和坡移浊积扇圈闭形成于基准面上升期,是该区主要的储油圈闭;滑塌浊积岩圈闭主要形成于基准面下降期,规模相对较小,储集物性较差。

High-resolution sequence stratigraphy and lithologic trap characteristics of Sha-3 member in the central sag of Dongying Depression

The drilling and seismic data in the central sag of Dongying Depression were comprehensively interpreted. The high-resolution sequence stratigraphical framework of Sha-3 member in the central sag of Dongying Depression was established. The middle member of Sha-3 can be divided into six short-term datum cycles. Every datum cycle includes many low-grade cycles of jacking base level. In accordance with the characteristics of the base levels and the forming mechanism of sandbody,the lithologic traps can be divided into three types including slump turbidite trap,slop-moving turbidity fan trap and sublacustrine fan trap. The formation and the distribution of traps were closely in connection with the evolution of base levels. The sublacustrine fan and slop-moving turbidite fan were formed during the rising stage of base level and consists of the main reservoirs. The slump turbidite was formed during the falling of base level and has the unfavorable reservoir properties.