渤海湾盆地东辛油田沙三中亚段重力流沉积砂体类型及含油性

Types and oil potential of gravity flow sandbodies in the middle Es^3 of Dongxin oilfield,the Bohai Bay Basin

渤海湾盆地东辛地区沙河街组三段中亚段沉积时期,深湖-半深湖中发育大量重力流沉积。根据岩心、测井及地震等资料综合分析,将重力流沉积划分为4种砂体类型,即与三角洲前缘滑塌相伴生的坡移堆积体、滑塌浊积扇、远源浊积岩以及洪水成因的水下碎屑流,并建立了该区重力流沉积模式。进一步通过油源、物性及圈闭条件对比研究,对各种砂体类型的含油性进行分析,认为滑塌浊积扇和部分远源浊积岩含油性好于坡移堆积体和水下碎屑流。

Gravity flow deposits were widely developed in deep-and semi-deep lakes during the deposition of the middle Es3 in the Dongxin area,the Bohai Bay Basin. An integrated analysis on core,logging and seismic data reveals that the gravity flow deposits can be classified into four types of sandbody, namely they are slope cumu- late complex associated with delta front slump, slump turbidite fan, distal turbidite, and subaquaceous debris flow deposits of flood origin. A gravity flow sedimentary model was also built up for the area. Oil potentials of various types of sandbodies are analyzed based on comparative studies of oil source,physical properties and trap conditions in the area. It is pointed out that oil potentials of slump turbidite fans and parts of the distal turbidite are higher than that of slope cumulate complex and subaquaceous debris flow.