鄂尔多斯盆地中东部奥陶系马家沟组沉积层序及其对储层发育的控制作用_黄正良解释.pdf

2015 年 9 月第 20 卷　第 5期 中 国 石 油 勘 探 CHINA…PETROLEUM…EXPLORATION DOI: 10.3969/j.issn.1672-7703.2015.05.003 鄂尔多斯盆地中东部奥陶系马家沟组沉积层序 及其对储层发育的控制作用 黄正良 1,2……武春英 1,2……马占荣 1,2……任军峰 1,2……包洪平 1,2 （1 中国石油长庆油田公司勘探开发研究院 ; 2 低渗透油气田勘探开发国家工程实验室） 摘 要：通过对鄂尔多斯盆地中东部地区奥陶纪马家沟期沉积及岩相古地理分析，首次系统厘定了马家沟组三级 及四级层序地层格架，将马家沟组划分为 3 个三级层序及 11 个四级层序。重点针对产气层马五段开展了四级层序的 岩相古地理演化研究，进而全面剖析了沉积层序对马五段白云岩储层空间展布的控制作用：（1）海平面升降加上中 央古隆起的隔挡作用，造成了白云岩化作用的差异，海退期为蒸发浓缩环境下的准同生白云岩化作用，海侵期为混合 水白云岩化作用；（2）白云岩化作用的差异导致了储层类型在纵向上的旋回性分布，海退期主要发育膏溶孔型白云 岩储层，海侵期主要发育晶间孔型白云岩储层；（3）层序内部储层平面分布受沉积相控制，海退沉积半旋回中，潮 间含膏云坪为有利沉积微相；海侵沉积半旋回中，潮间藻屑滩为有利沉积微相。 关键词：鄂尔多斯盆地；马家沟组；沉积层序；海侵体系域；高位体系域；白云岩储层 中图分类号：TE122.2　　　　　文献标识码：A Sedimentary Sequence of Ordovician Majiagou Formation in Central and Eastern Part of Ordos Basin and Its Control over Reservoir Development Huang Zhengliang1,2, Wu Chunying1,2, Ma Zhanrong1,2, Ren Junfeng1,2, Bao Hongping1,2 (1 Exploration and Development Research Institute of PetroChina Changqing Oilfield Company; 2 National Engineering Laboratory for Exploration and Development of Low-permeability Oil Gas Fields) Abstract: Based on analysis of sedimentation and lithofacies paleogeography of Ordovician Majiagou Formation in the central and eastern part of Ordos Basin, this paper, for the first time, defines the 3rd and 4th sequential stratigraphic configuration of Majiagou Formation and divides Majiagou Formation into three 3rd sequences and 11 4th sequences. The study is focused on lithofacies paleogeographic evolution of the 4th sequences of Ma5, a gas-producing horizon, fully analyzing the controlling role of sedimentary sequences on distribution of dolomite reservoirs. (1) Fluctuations of sea level and ejection of central paleo-uplift caused the differences in dolomitisation – penecontemporaneous dolomite in the regressive period and mixing dolomite in the transgressive period. (2) The differences in dolomitisation led to a vertically cycled distribution of reservoirs with development of gypsum-dissolved dolomite reservo