石油与天然气地质 ›› 2014, Vol. 35 ›› Issue (5): 622-631,638.doi: 10.11743/ogg20140506

• 油气地质 • 上一篇    下一篇

四川盆地寒武系盐相关构造及其控油气作用

李双建1,2, 孙冬胜1, 郑孟林1, 孟宪武3   

  1. 1. 中国石化 石油勘探开发研究院, 北京 100083;
    2. 中国石化 构造与储层实验室, 北京 100083;
    3. 中国石化 西南油气分公司, 贵州 贵阳 550001
  • 收稿日期:2014-02-14 修回日期:2014-08-01 出版日期:2014-10-08 发布日期:2014-10-17
  • 第一作者简介:李双建(1978- ),男,博士、高级工程师,含油气盆地分析。E-mail:lishuangjian.syky@sinopec.com。
  • 基金项目:

    国家科技重大专项(2011ZX05005-001);国家重点基础研究发展计划(973计划)项目(2012CB412800);国家自然科学基金项目(40739904)。

Salt-related structure and its control on hydrocarbon of the Cambrian in Sichuan Basin

Li Shuangjian1,2, Sun Dongsheng1, Zheng Menglin1, Meng Xianwu3   

  1. 1. Petroleum Exploration & Production Research Institute, SINOPEC, Beijing 100083, China;
    2. Structural Geology and Reservoir Laboratory, SINOPEC, Beijing 100083, China;
    3. Southwest Oil and Gas Field Company, SINOPEC, Guiyang, Guizhou 550001, China
  • Received:2014-02-14 Revised:2014-08-01 Online:2014-10-08 Published:2014-10-17

摘要:

四川盆地东部和南部中、下寒武统广泛发育膏盐岩层系,形成了多种样式的盐相关构造。依据露头、钻井和地震资料分析,认为四川盆地寒武系膏盐岩形成于克拉通内局限台地环境,具有时代老、埋藏深、厚度分布不均、膏多盐少及伴生岩石类型多样等特点。受膏岩和盐岩流动性差异、构造挤压、基底断裂和滑脱作用等多种因素影响,膏盐岩层系相关构造分层性明显。盐上层表现为背斜、推覆体和断块背斜构造;盐层表现为盐枕构造、盐缩颈形成的鱼尾构造和岩盐塑性流动构造;盐下层则表现为受复杂基底断裂控制的叠瓦冲断和背冲断块构造。寒武系膏盐岩为震旦系-下寒武统目的层系的油气聚集提供了优质的封盖条件;同时,膏盐岩自身参与的TSR反应(硫酸盐热化学还原反应)和表生溶蚀也可以有效地改善储层的储集物性。更重要是,寒武系膏盐岩作为区域滑脱层对盐上和盐下震旦系-下古生界构造变形起着重要控制作用,形成一系列含油气构造圈闭。从盐相关构造的发育特点来看,鄂西-渝东区的盐下断背斜和川东南地区的盐上断背斜是有利的勘探目标。

关键词: 盐相关构造, 膏盐岩, 控油气作用, 勘探目标, 寒武系, 四川盆地

Abstract:

Gypsolyte-salt layers of the Middle-Lower Cambrian are widely developed in the southern and eastern Sichuan Basin,resulting in a variety of salt-related structures.Analyses of outcrop,drilling and seismic data reveal that the gypsolyte-salt layers of the Cambrian in Sichuan Basin formed on restricted intra-craton platform and has the characteristics of old age,deep burial depth,uneven thickness,more gypsolyte and less salt,and various associated rock types.The gypsolyte-salt related structures show obvious layering due to the differential gypsolyte and salt mobility,tectonic compression,basement faults,and detachment,.The post-salt structures are mainly anticlines,thrust nappes and faulted-anticlines.The structures within the salt layers are mainly salt pillows,tail structures and plastic flow structures.The presalt structures mainly include imbricate thrusts and pop-up structures controlled by the complex basement faults.The gypsolyte-salt layers of the Cambrian provide good sealing conditions for hydrocarbon accumulation in the Lower Sinian-Lo-wer Cambrian.Meanwhile,they also can improve reservoir quality through TSR and supergene dissolution that they are involved.Even more important,as a region detachment layer,the gypsolyte-salt rock plays an important role in the structural deformation of the post-salt and pre-salt Sinian-Lower Paleozoic,resulting in a series of hydrocarbon traps.According to the characteristics of gypsolyte-salt related structures,the pre-salt faulted anticlines in western Hubei-eastern Chongqing and post-salt faulted anticlines in southeast Sichuan are the favorable exploration targets.

Key words: salt-related structure, gypsolyte-salt rock, control on hydrocarbon, exploration target, Cambrian, Sichuan Basin

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