辽河油田锦99块扇三角洲前缘储层层次分析

Architectural boundaries of the fan delta front reservoirs in the quadrant Jin-99 of the Liaohe Oil Field,Liaoning

关键词:  锦99块  沙四上亚段  扇三角洲前缘  岩相  层次界面

Key words:  quadrant Jin-99  upper submember of the 4th member of the Shahejie Formation  fan delta front  lithofacies  architectural boundary

摘要:

辽河油田锦99块沙河街组四段上亚段杜家台油层是典型的扇三角洲前缘沉积,主要由扇三角洲前缘水下分流河道和河道砂坝组成。依据高分辨率层序地层学和储层构型理论,采用层次分析方法,对锦99块沙四上亚段扇三角洲前缘砂体构型界面进行了层次表征。综合利用岩心资料和测井资料,识别出11种岩相类型和4种岩相组合。根据高频湖泛面、冲刷面、粒序突变面和岩相转换面将沙四上亚段Ⅰ₃砂层组和Ⅱ₁砂层组划分为6个短期旋回、15个超短期旋回。在等时格架内,建立了扇三角洲前缘储层5级构型界面层次,层次界面以三级和四级为主,四级界面分布较稳定,三级界面零星分布。总结出两种层次界面分布模式:较稳定分布的界面和随机型分布的界面。储层层次分析为研究区构型约束建模提供了依据。

Abstract:

The Dujiatai oil reservoirs in the upper submember of the 4th member of the Shahejie Formation in the quadrant Jin-99 of the Liaohe Oil Field,Liaoning represent the representative fan delta front deposits,which are made up of the subaqueous distributary channel and channel bar deposits. According to core examination and well logs, 11 lithofacies types and 4 lithofacies associations are descriminated. Futhermore, in the light of high-frequency flooding surface,scour surface,sharp graded facies and lithofacies boundary,6 short-term and 15 ultrashort-term cycles are recognized for the I₃ and II₁ sandstone measures in the upper submember of the 4th member of the Shahejie Formation. Five-order architectural boundary systems are established for the fan delta front deposits within the isochronous stratigraphic framework,and two types of architectural boundary models are constructed. The results of research in this study may provide the basis for the establishment of the three-dimensional architectural models in the study area.