陆相层序地层研究中几个问题的探讨

从层序地层学的本质出发,结合渤海海域油田研究实际,对层序地层划分与对比的本质、三级层序内部划分问题以及不同体系域三角洲砂体沉积特征进行了探讨,认为搞清研究区沉积环境变化规律是进行层序地层研究的根本,三级层序内部划分必须重视直接反映沉积环境变化的古生物资料;正确认识层序地层、古地貌、物源之间的关系是搞清三角洲砂体沉积特征的关键;只有搞清砂体沉积特征分布规律,才会对不同体系域、不同类型的隐蔽圈闭具有更清晰的认识,从而为隐蔽油气藏勘探提供有益的启示与参考。

A discussion on several problems of continental sequence stratigraphy

Starting from the fundaments of sequence stratigraphy and in combination with some case studies of Bohai offshore oilfields,several problems are discussed,including essences of stratigraphic sequence division and correlation,subdivision within third-order sequences and deltaic sand-body characteristics in different tracts.It is fundamental for a sequence stratigraphy study to clearly understand environment changes in the study area,and the fossil evidences that directly reflect sedimentary environments must be emphasized when making a subdivision within third-order sequences.It is a key for understanding deltaic sand-body characteristics to correctly identify the relationships among sequence,palaeogeomorphology and provenance.Only when the characteristics of sand-bodies are well understood,can various tracts and various types of subtle trap be clearly defined,therefore giving helpful enlightenments to subtle reservoir exploration.