摘要
通过露头剖面追踪实测、岩相分析及精细构型解剖,对准噶尔盆地西北缘吐孜阿克内沟八道湾组砾质辫状河露头进行了系统研究,明确了其岩相特征及内部构型,建立了基准面上升过程中砾质辫状河沉积构型模式并对隔夹层展布及其控制的剩余油进行了分析.露头中识别出8种岩相类型和6类岩相组合,辫状河道及砾质坝为砾质辫状河主要的构型单元.研究结果表明:基准面上升早期砾质辫状河以辫状河道构型单元发育为主,砾质坝构型单元不甚发育,据河道底部形态将辫状河道分为面状侵蚀河道和局部侵蚀河道,单一辫状河道宽度多大于150m,以侧向拼接为主.基准面上升中期辫状河道构型单元和砾质坝构型单元均较发育,侧向呈河坝相间分布的特征,该时期河道以局部侵蚀为主,单一辫状河道多呈垂向叠置样式,单一辫状河道宽度100~150m,砾质坝宽度约50m.基准面上升晚期发育砂质坝,且砾质坝与砂质坝规模较大,总体呈宽坝窄河道的特征,单一辫状河道宽度约50m,砂质坝宽度50~100m,厚度3~5m.砾质辫状河总体为"砾包砂"的沉积特征,其内部隔夹层主要有4类:近水平稳定分布的泛滥平原泥炭隔层,倾斜展布的河道侧积细砂岩夹层,河道底部下凹的钙质夹层及河道顶部废弃河道粉砂岩夹层.侧积夹层及废弃河道规模较小,对剩余油的控制不明显,钙质夹层展布范围较广且分布较稳定,底部剩余油较富集.
Through outcrop profile tracing measurement,lithofacies analysis and architecture dissection of the gravel braided river outcrop in the lower Jurassic Badaowan in Azitukeneigou,northwest Junggar basin,the lithofaies and inter architecture characteristics were clarified.The architecture models in different base level rising stages were established and interlayers distribution were analyzed.Eight types of lithofacies and six associations were identified.Results show that braided channel and gravel bar are the main architecture units in braided river.In the early stage of base level rising,channel is the main architecture unit,while gravel bar rarely develops.According to the bottom shape,channels can be divided into planar erosion channel and local erosion channel.Single braided channel is basically wider than 150 mand laterally stitched with each other.In the middle stage of base level rising,the channel and gravel bar are well developed,and are laterally contacted with each other.Featured by local erosion,single channels are vertically stacked,with the width of 100 to 150 m.The width of gravel bar is around 50 m.In the later stage of base level rising,sandy bar begins to develop.The bars are large and channels are small.The distribution pattern is＂wide bar and narrow channel＂.The single channel is of around 50 m wide.The gravel bar is of 50 to 100 m wide and 3 to 5 m thick.Gravel braided river has the characteristic of＂gravel packed sandstone＂.There are four types of interlayers：mudstone interlayer with horizontal distribution developed in flood plain,lateral sandy interlayer with inclined distribution,concaved calcic interlayer developed in bottom channel and abandoned sandy channel interlayer.Lateral interlayer and abandoned sandy channel interlayer have little control on the distribution of remaining oil for their small size,while the bottom of calcic interlayer accumulates abundant remaining oil.
作者
秦国省
胡文瑞
宋新民
赵亮
陈玉琨
田雅洁
匡明
QIN Guosheng;HU Wenrui;SONG Xinmin;ZHAO Liang;CHEN Yukun;TIAN Yajie;KUANG Ming(PetroChina Research Institute of Petroleum Exploration ＆ Development,Beijing 100083,China;CNPC Consulting Center,Beijing 100724,China;PetroChina Xinjiang Oilfield Company,Karamay,Xinjiang 834000,China)
出处
《中国矿业大学学报》
EI
CAS
CSCD
北大核心
2018年第5期1008-1020,共13页
Journal of China University of Mining & Technology
基金
国家重大科技专项(2016ZX05010-005)
关键词
准噶尔盆地
砾质辫状河
露头解剖
岩相特征
构型单元
隔夹层
剩余油
Junggar basin
gravel braided river
outcrop dissection
lithofacies characteristics
architecture unit
interlayer
remaining oil
作者简介
通信作者：秦国省（1988-），男，山东省济宁市人，博士研究生，从事油气田开发地质及三维建模方面的研究．E-mail：qin8002008@163．com Tel：010—83599044
