石油与天然气地质 ›› 2013, Vol. 34 ›› Issue (3): 370-375.doi: 10.11743/ogg20130313

• 盆地构造 • 上一篇    下一篇

塔北草湖凹陷形成演化新认识及油气地质意义

姚泽伟1, 何光玉1, 郑晓丽1, 漆立新2, 张洪安2, 云露2, 林璐1, 王文侠1   

  1. 1. 浙江大学地球科学系, 浙江 杭州, 310027;
    2. 中国石化西北油田分公司, 新疆 乌鲁木齐, 830011
  • 收稿日期:2012-10-12 修回日期:2013-04-02 出版日期:2013-06-28 发布日期:2013-07-17
  • 作者简介:姚泽伟,(1987- ),男,博士研究生,构造地质学、岩石学。E-mail:zealway@zju.edu.cn。

New ideas about the evolution of Caohu sag in the northern Tarim Basin and its significance for petroleum geology

Yao Zewei1, He Guangyu1, Zheng Xiaoli1, Qi Lixin2, Zhang Hong'an2, Yun Lu2, Lin Lu1, Wang Wenxia1   

  1. 1. Department of Earth Sciences, Zhejiang University, Hangzhou, Zhejiang 310027, China;
    2. Northwest Oilfield Company of SINOPEC, Urumqi, Xinjiang 830011, China
  • Received:2012-10-12 Revised:2013-04-02 Online:2013-06-28 Published:2013-07-17

摘要: 基于二维地震剖面的精细地质解释,并结合钻井资料的分析,提出了塔北地区古生代以来草湖凹陷形成演化的新认识,认为塔北草湖凹陷东、西两侧斜坡的形成时间与形成机理存在明显的差异。凹陷西侧中-上奥陶统自东向西超覆沉积特征明显,表明西斜坡主要形成于加里东中期,形成机理是在持续区域挤压背景下,草湖地区相对沉降,阿克库勒地区相对隆升,表现出沉积型凹陷斜坡的特征;而凹陷东侧可见奥陶系、志留系等地层被强烈抬升并遭受剥蚀,角度不整合于上泥盆统-石炭系之下,后者又角度不整合于三叠系之下,表明东斜坡主要形成于加里东晚期和海西早、晚期的强烈构造变形,以海西晚期为主,表现出构造型凹陷斜坡的特征。草湖凹陷西侧有利于发育下奥陶统岩溶型地层圈闭,凹陷东侧有利于发育志留系、石炭系和三叠系超覆型岩性圈闭及中-上奥陶统不整合型地层圈闭、下奥陶统岩溶型地层圈闭,它们是下一步油气勘探的重要方向。

关键词: 沉积型凹陷斜坡, 构造型凹陷斜坡, 油气圈闭, 古生代, 草湖凹陷, 塔里木盆地

Abstract: The evolution of Caohu sag in northern Tarim Basin is discussed in this paper based on geological interpretation of two-dimensional seismic profiles and analysis of drilling data.We present new ideas about the evolution of Caohu sag since Paleozoic.The time and mechanism of formation of the eastern and western slopes of Caohu sag are apparently different.In the western side of the sag,the Middle-Upper Ordovician show distinct overlapping characteristics from east to west,indicating that the western slope of Caohu sag was developed mainly in the Middle Caledonian as the result of the subsiding of Caohu area and the uplifting of Akekule Uplift under the continuous regional compression.The western slope has the characteristics of depositional sag slope.While in the eastern side of the sag,the Silurian-Ordovician were strongly uplifted and eroded and underlie unconformably the Upper Devonian-Carboniferous,which in turn underlie unconformably the Triassic.This demonstrates that the eastern slope was developed in the Late Caledonian as well as the Early and Late Hercynian as the result of the intense tectonic deformation,with the Late Hercynian being the dominant.The eastern slope shows the characteristics of structural sag slope.The western side of Caohu sag is favorable for the development of Late Ordovician karst stratigraphic traps,while the eastern side is favorable for the development of overlapped lithologic traps in the Silurian,Carboniferous and Triassic,unconformity stratigraphic traps in the Upper-Middle Ordovician,as well as the karst stratigraphic traps in the Lower Ordovician.They are the major potential exploration targets in the future.

Key words: depositional sag slope, structural sag slope, petroleum trap, Paleozoic, Caohu sag, Tarim Basin

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