摘要：

以测井资料和岩心观察为基础，对鄂尔多斯盆地北部苏里格庙含油气区的二叠系山西组及下石盒子组盒八段识别出了辫状河、曲流河、三角洲和湖泊等4种沉积相类型。利用层序地层学原理，将山西组和下石盒子组盒八段划分5个三级沉积层序，建立了苏里格庙含油气区层序地层格架。编制了以体系域为单位的山西组和下石盒子组盒八段沉积期岩相古地理图，探讨了层序地层格架内的山西组和下石盒子组盒八段沉积期岩相古地理特征及演化规律。山西期古地理格局呈南北向相分异的曲流河—三角洲沉积；盒八段沉积期冲积体系大范围向研究区南部迁移，形成了以辫状河沉积为主的河流—三角洲沉积。河道砂体是苏里格庙含油气区有利的砂质储集体类型，主要发育在低位体系域。实践表明，以体系域为单位编制的岩相古地理图，可以清楚地展示不同沉积时期的沉积微相展布与迁移变化，是有利储层预测的一种有效方法。

Abstract:

Based on the analysis of drilling data and core, the sedimentary facies of the Shanxi formation to Member 8 of Xiashihezi formation of Permian in Suligemiao oil and gas-bearing area, north Ordos basin, are divided into braided river, meandering river, delta and lake. By the theory of sequence stratigraphy, the Shanxi formation and Member 8 of Xiashihezi formation are divided into 5 sequences, and the sequence stratigraphic framework is set up. The lithofacies paleogeography map is drawn according to system tract. The feature and evolution of the lithofacies paleogeography are discussed in the sequence stratigraphic framework. During the sedimentary period of Shanxi formation, the paleogeography situation was meandering river-delta deposit, which has sedimentary differentiation from north to south. During the sedimentary period of Member 8 of the Xiashihezi formation, the alluvial system removed into the south of study area widely and formed river-delta deposit, in which the braided river is dominant. The channel sand body is high quality reservoir in Suligemiao oil and gas-bearing area, and its development is relative to lowstand system tract. By the palaeogeography mapping in the unit of system tract, the distribution and transferred direction of sedimentary microfacies are shown distinctly. It is an effective method to prospect the high quality reservoir.