王钦 刘振旺 肖良 李相传

摘 要：为了研究靖吴地区长6储层沉积特征，通过岩心观察、薄片鉴定、沉积构造和测井曲线响应等综合分析，本文对研究区沉积相标志、沉积相类型、微相展布及微相演化规律进行研究。结果显示，靖吴地区长6储层沉积体系为河控三角洲沉积体系，且三角洲前缘亚相、前三角洲-浅湖沉积占主导地位。沉积微相有水下分流河道、水下天然堤、分流间湾、水下决口扇、河口坝、远砂坝六种，三角洲前缘的水下分流河道是储层砂岩发育的骨架，且水下分流河道砂体是储层最有利储层发育的相带，其次为三角洲前缘河口坝砂体。

关键词：靖吴地区;沉积微相;长6储层;鄂尔多斯盆地

中图分类号：P618.13文献标识码：A文章编号：1003-5168（2020）35-0141-05

Abstract： In order to study the sedimentary characteristics of Chang-6 reservoir in Jingwu area， through comprehensive analysis of core observation， thin section identification， sedimentary structure and logging curve response， this paper studied the sedimentary facies signs， sedimentary facies types， microfacies distribution， and microfacies evolution laws in the study area. The results show that the Chang 6 reservoir sedimentary system in the Jingwu area is a river-controlled delta sedimentary system， and the delta front subfacies and pre-delta-shallow lake sediments dominate. There are six types of sedimentary microfacies， namely underwater distributary channel， underwater natural dike， distributary bay， underwater rupture fan， estuary dam， and remote sand dam. The underwater distributary channel of the delta front is the framework of the reservoir sandstone development， and the underwater distributary channel sand body is the most favorable facies belt for the reservoir development， followed by the delta front estuary bar sand body.

Keywords： Jingwu area;sedimentary microfacies;Chang 6 reservoir;Ordos Basin

鄂尔多斯盆地中生界上三叠统延长组是一套以河流、湖泊相为主的陆源碎屑沉积，记录了湖盆的形成、发展和萎缩的演化过程。近年来，随着靖吴油田的上产，三叠系油藏潜力缺乏，长6油层组作为主要的建产层位，储层物性差，油水关系模糊不定一直是没有解决的问题。沉积相见证了盆地形成、演化和消亡的过程，不仅体现地层和岩石类型的形成条件、时空展布及演化规律，同时可作为分析沉积盆地性质、构造背景的重要依据[1-2]。明确沉积微相、沉积展布及小层间沉积微相间的接触形式，对开展精细注水，提高油田开发水平具有重要的作用。因此，人们需要对研究区开展沉积相研究。

1 沉积相标志

1.1 岩石学成分