松辽盆地梨树凹陷深部断陷沉积体系及层序地层特征

松辽盆地梨树凹陷下部为断陷构造层序,上部为拗陷构造层序。断陷构造层序由四个层序组成,包括沙河子组下、中部,营城组和登娄库组。在深部断陷中广泛发育了冲积扇-扇三角洲体系、三角洲体系和湖泊体系沉积,其中湖泊体系沉积所占比例较大,构成梨树凹陷主要的烃源岩,辫状平原型扇三角洲砂体和三角洲砂体构成深部断陷主要储集层。本文在沉积体系和成因地层格架研究基础上,阐述深部断陷的层序地层及含油气性特征。 

THE CHARACTERS OF THE DEPOSITIONAL SYSTEMS AND SEQUENCE STRATIGRAPHY OF THE DEEP FAULTDOWN DEPRESSION IN THE LISHU DEPRESSION OF THE SONGLIAO BASIN

The Lishu Depression of the Songliao Basin can be divided into a faultdown depressionstructural sequence in the lower part and a depression structural sequence in the upperpart.The faultdown depression structural sequence could consist of four sub-sequences ofthe lower and middle parts of the Shahezi Formation,the Yingcheng Formation and theDeng louku Formation.In lower part of deep faultdown depression,the alluvial fan-fandelta system,delta system and lacustrine system are widespreaded,of which lacustrinesedimentary system takes a large proportion and could be considered as the main sourcerocks of hydrocarbons in the Lishu Depression,while the plaiting plains-type fan delta sandmassif and delta sand massif could be the main reservoirs in deep faultdown depression.This paper describes the stratigraphic sequence and petroliferous characters of deep fault-down depression based on the geological studies of the depositional systems and the forma-tion of sedimentary sequences.