鄂尔多斯盆地陇东地区延长组沉积特征及模式分析

Analysis of sedimentary characteristics and mode of Yanchang formation in Longdong Area,Ordos Basin

鄂尔多斯盆地陇东地区三叠系延长组富含丰富的油气资源。通过针对大量野外露头、岩心和地球物理资料的分析,可以得知延长组沉积类型为浅水辫状河三角洲。此外,该组地层沉积还具有大型坳陷湖盆地质背景,因此该地区形成的辫状河三角洲具有粒度较粗、成分成熟度和结构成熟度较低、水下分支河道多叉、砂体沉积厚且延伸远、分布广等沉积特征。本文通过对鄂尔多斯盆地陇东地区三叠系延长组的大量测井资料结合野外露头信息进行分析,简要分析了该地区的沉积特征及沉积模式,为该区的下一步的石油勘探开发提供理论指导依据。

The Triassic Yanchang formation in Longdong Area,Ordos Basin is abundant in oil and gas resources.The sedimentary mode of Yanchang formation is shallow braided river delta by analysis on field outcrop,core and geophysical data.In addition,the formation also has a geological background of large sedimentary lacustrine,so the braided river delta in this area features coarser,low compositional maturity and textural maturity,multi-fork of underwater distributary channel,as well as thick,far and wide distribution of sand body.The sedimentary characteristics and depositional model of the area are demonstrated via analysis of data of logging and outcrops,which will offer reference for further exploration and development.