摘要
以高精度层序地层理论为指导,综合大量的钻测井资料和岩心观察,在红星地区古近系沙河街组一段和东营组三段建立了储层规模的高精度层序格架,划分出4个三级层序、19个四级层序和一系列五级层序;测井曲线和岩心观察相结合进行沉积微相分析,识别出扇三角洲前缘和辫状河三角洲前缘水下分流河道、河口坝、前三角洲、决口扇、分流间湾等微相类型;主要储层砂体发育的四级层序沉积体系平面编图表明,不同沉积相或微相无疑是造成砂体形态、分布及储集性变化的直接影响因素。沙一段以扇三角洲前缘水下分流河道或分流河道相储层为主,粒度粗,单一砂层厚度大;而东三段以河流或辫状河三角洲砂体为主,粒度较细,单一砂层较薄。平面上,从北东向南或南西方向显示出从分流河道砂体向三角洲前缘远端坝砂体过渡的变化趋势。沉积相的分布格局控制着砂体类型和分布。
Guided by high-resolution sequence stratigraphy theory, combined with lots of logging data and core observation, a reservoir-scale high-resolution sequence stratigraphy framework of the Eogene first member of Shahejie formation and the third member of Dongying formation has been established in Hongxing area. 4 3rd order sequences and 19 4th order paramsequence sets and series of 5th order paramsequences have been classified in this paper. According to the logging analysis and core observation, several of sedimentary microfacies of Sha1 and Dong3 have been recognized, such as fan delta front subdistritary channel, mouth bar, front delta, flooding fan, distributary interval and so on. The depositional systems mapping of 4th order sequence show that different sedimentary microfacies form different sand configuration and distribution and physical characteristic of reservoir. Because fan delta front sub-distributary channel or distributary channel is the major depositional microfacies of Sha1, the reservoir mainly is coarse grade and single thick sand. While braided or braided delta is the major depositional system of Dong3, the reservoir mainly is fine grade and single thin sand. In literally, there shows the evolution trend from northeast and southwest distributaries channel sand to delta front far bar sand. The distribution configuration of depositional system controlled the sand types and distribution.
出处
《西北地质》
CAS
CSCD
2008年第2期73-80,共8页
Northwestern Geology
基金
国家重点基础发展规划(973)项目(2006CB202302)
关键词
高精度层序地层
沉积体系
古近系
红星地区
东部凹陷
high-resolution sequence stratigraphy
depositional system
Eogene
Hongxing area
eastern depression
