层序地层学应用于陆相湖盆中隐蔽油气藏的成因解释

A DISCUSSION ON THE GENETIC INTERPRETATION AND CLASSIFICATION OF SUBTLE TRAP RESERVOIR BY USING SEQUENCE STRATIGRAPHIC METHOD

研究表明 ,赋存于沉积地层中的油气藏与各种级别的层序地层界面存在着密切的联系。陆相盆地中油气受层序界面、初次湖泛面、最大湖泛面以及更次级的层序地层界面的影响与控制 ,形成不同类型的隐蔽型油气藏。因此 ,从层序地层和沉积过程的角度解剖含油气盆地中不同构造和古地理单元岩性—地层油气藏形成的机理和油气藏类型 ,分析主要层序地层界面对沉积地层中油气藏形成和分布的控制作用 ,具有重要的理论和现实意义。本文从层序地层和沉积过程的角度解剖陆相盆地中不同古地理、古地貌单元隐蔽油气藏形成的机理和油气藏类型 ,阐述主要层序地层界面对油气藏形成过程和分布规律的影响与控制作用 ,并进一步对不同成因类型的油气藏提出简要的分类方案。

Different scales of lake level changes can result in various sequence stratigraphic boundaries in terrestrial strata, such as sequence boundaries (SB), maximal flooding surface (MFS), first flooding surface (FFS) and other sub-flooding surface (SFS). It is suggested in this study that some intimate relationships existed between strata oiliness and these boundaries. Being controlled by these boundaries or surfaces, different types of stratigraphic and/or lithologic reservoirs can be formed. In this article, Baiyinchagan depression of Erlian Basin and Chengdao oil field of Bohai Bay Basin were considered as two examples for the analysis about the mechanism of reservoir formation and types in terrestrial rift-subsidence basin from a viewpoint of sequence stratigraphy and depositional process. The control of the great sequence stratigraphic boundaries toward formation and distribution of reservoirs was also discussed.