石油与天然气地质 ›› 2016, Vol. 37 ›› Issue (6): 828-837.doi: 10.11743/ogg20160604

• 油气地质 • 上一篇    下一篇

焦石坝地区中、古生界构造特征及其页岩气地质意义

佘晓宇1,2, 陈洁1,2, 张士万3, 舒志国3, 郁飞3, 李冬冬1,2, 龚晓星4   

  1. 1. 长江大学 油气资源与勘探技术教育部重点实验室, 湖北 武汉 430100;
    2. 长江大学 地球物理与石油资源学院, 湖北 武汉 430100;
    3. 中国石化 江汉油田分公司 勘探开发研究院, 湖北 武汉 430223;
    4. 成都理工大学 能源学院 四川 成都 610059
  • 收稿日期:2016-06-23 修回日期:2016-11-03 出版日期:2016-12-08 发布日期:2017-01-02
  • 作者简介:佘晓宇(1963-),男,博士、副教授,矿产普查与勘探。E-mail:shexiaoyu2000@163.com。
  • 基金资助:
    国家自然科学青年基金(41402098)。

Tectonic characteristics and their shale gas geological significance of the Mesozoic-Paleozoic in Jiaoshiba area,the Sichuan Basin

She Xiaoyu1,2, Chen Jie1,2, Zhang Shiwan3, Shu Zhiguo3, Yu Fei3, Li Dongdong1,2, Gong Xiaoxing4   

  1. 1. Key Laboratory of Exploration Technologies for Oil and Gas Resources, Ministry of Education, Yangtze University, Wuhan, Hubei 430100, China;
    2. School of Geophysics and Oil Resources, Yangtze University, Wuhan, Hubei 430100, China;
    3. Exploration and Development Research Institute, Jianghan Oilfield Company, SINOPEC, Wuhan, Hubei 430223, China;
    4. College of Energy Resources, Chengdu University of Technology, Chengdu, Sichuan 610059, China
  • Received:2016-06-23 Revised:2016-11-03 Online:2016-12-08 Published:2017-01-02

摘要: 通过二维、三维地震剖面解释和运用平衡剖面技术观点,对焦石坝地区基底结构、中、古生界构造特征及其构造演化进行了研究。研究结果表明,该区存在着基底卷入和盖层滑脱2种构造类型。基底卷入型有背冲背斜、对冲向斜、叠瓦逆冲、正花状扭动和多字形扭动5种构造样式。盖层滑脱型有断展或断弯、断滑、叠瓦逆冲、叠瓦反冲、冲断楔5种构造样式和组合。燕山早、中期是该区的2个主要构造变形期,在燕山早期,中、古生界与基底及其内幕之间近水平向西拆离滑脱推覆,形成了侏罗山隔挡式背-向斜交替褶皱。方斗山断裂与大天池背斜之间的焦石坝地区为挤压宽缓复向斜背景;在燕山中期,受东邻隔槽带中、深层基底拆离向西强烈冲断作用,焦石坝地区形成了仰冲-逆冲-掩冲构造格局,经历基底叠瓦冲断-盖层滑脱-左行压扭3个变形幕,形成了焦石坝双层背冲背斜及翼部的断褶带。石门断褶带具有多层滑脱褶皱特征,乌江断褶带具有滑脱与左行压扭的性质。构造变形性质与类型、龙马溪组-五峰组滑脱程度、层滑作用产生的构造缝是该区形成大型页岩气田重要的构造影响因素。

关键词: 双层背冲, 多层滑脱, 基底拆离, 隔挡式褶皱, 页岩气, 焦石坝背斜及周缘, 四川盆地

Abstract: Through 2D and 3D seismic interpretation and application of balanced cross section technique,basement structure,and tectonic characteristics and its evolution of the Mesozoic-Paleozoic of Jiaoshiba area,the Sichuan Basin are analyzed in this study.The results show that there are two types of structures in the study area.The first type is basement-involved structure,which is characterized by five structural patterns and assemblages,including back thrust anticlines,ramp syncline,imbricate thrusting,positive flower wrench and "多"-shaped wrench.The other type is cap detachment structure,which is characterized by five structural patterns and assemblages,including fault-propagation or fault-bend,fault-slipping,imbricate thrusting,imbricate ramp and thrust wedge.Additionally,the Early and Middle Yanshanian period are two major tectonic deformation periods.During the Early Yanshanian period,the nearly horizontal westwards detachment and decollement-nappe structures occurred along the interface between the Mesozoic-Paleozoic and the basement and the interfaces within the basement,resulting in the anticline-syncline alternating Zhuluoshan fold.The Jiaoshiba area between Fangdoushan fault and Datianchi anticline is within a broad compressional synclinorium structural background.During the Middle Yanshanian period,the detachment of the middle-deep burial basement in the eastern trough-like fold belt caused intensive westward thrusting,and then led to the formation of the tectonic framework of obduction-thrust-overthrust in the Jiaoshiba area.The double-layer back-thrusting anticline and faulted fold belt in the flanks were formed in Jiaoshiba area after three deformation episodes,including basement-involved imbricate thrusting-cap rock decollement-left-lateral transpression.Furthermore,Shimen faulted fold belt is characterized by multi-layer detachment folding structure and Wujiang fault-fold belt is characterized by detachment and left-lateral transpression structure.The tectonic deformation properties and types,decollement degree of the Longmaxi and Wufeng Formations,and layer-slipping structural fractures are the major tectonic factors controlling the shale gas play.

Key words: double-layer back thrusting, multi-layer decollement, basement detachment, ejective folding, shale gas, Jiaoshiba anticline and its periphery, Sichuan Basin

中图分类号: