本文应用层序地层学方法,通过钻井、测井、地震反射等标志,将东营凹陷沙四段上亚段划分为一个三级层序,并以地层叠置样式、岩性、岩相的变化细分出低位、湖侵和高位体系域,在连井剖面层序对比的基础上建立了研究区沙四段上亚段层序地层格架。通过岩芯、钻井、测井、古生物等资料的分析识别出沙四段上亚段主要发育扇三角洲、近岸水下扇、三角洲、湖泊等主要相类型。本文首次系统分析了东营凹陷沙四段上亚段沉积相的构成、演化与分布规律,明确了各种不同沉积砂体的相互联系以及共生规律,建立了沙四段上亚段沉积模式,这对于指导研究区隐蔽油气藏的勘探具有重要意义。
The upper submember of the 4th member of the Shahejie Formation in the Dongying depression can be divided into one sequence according to sequence boundaries, such as well logging curve and seismic reflective characteristics. Lowstand, lacustrine transgressive and highstand systems tracts can be subdivided by the stacking patterns of stratigraphy, changes of lithology and lithofacies. The sequence stratigraphic correlation in well-tie sections made it possible to construct the regional stratigraphic framework. Fan delta, near-shore underwater fans, delta, beach bar and limestone beach sedimentary system fades can be identified by fully applying the core, drilling, logging and paleontology data. The architecture, evolution, distribution of sedimentary faces of upper Es^4 in the Dongying depression is firstly analyzed; the relation and coexisting of various sandstones is clarified; the sedimentary mode is established; These researches have great significance in finding out subtle traps in this depression.