古地理学报 ›› 2025, Vol. 27 ›› Issue (4): 1044-1063. doi: 10.7605/gdlxb.2025.082

• 古地理学及矿产资源 • 上一篇    下一篇

四川盆地中二叠统茅口组构造-岩相古地理特征及有利储集区带分布*

文龙1(), 罗冰1, 杨文杰2,3, 陈骁1, 张本健1, 许强2, 李明隆2, 肖笛2, 乔占峰4, 谭秀成2()   

  1. 1 中国石油西南油气田公司,四川成都 610051
    2 中国石油集团碳酸盐岩储层重点实验室西南石油大学研究分室,四川成都 610500
    3 中国石化勘探分公司,四川成都 610041
    4 中国石油杭州地质研究院,浙江杭州 310023
  • 收稿日期:2025-02-14 修回日期:2025-03-15 出版日期:2025-08-01 发布日期:2025-07-30
  • 通讯作者: 谭秀成,男,1970年生,教授,博士生导师,主要从事碳酸盐岩沉积学与储层地质学研究。E-mail: tanxiucheng70@163.com。
  • 作者简介:

    文龙,男,1977年生,博士,高级工程师,主要从事天然气勘探地质综合研究及管理工作。E-mail:

  • 基金资助:
    *国家自然科学基金与中石油联合基金重点项目(U23B20154); 国家自然科学基金面上项目(42172166); 中国石油—西南石油大学创新联合体科技合作项目(2020CX010000)

Tectonic-lithofacies palaeogeographic characteristics and distribution of favorable reservoir zones of the Middle Permian Maokou Formation in Sichuan Basin,China

WEN Long1(), LUO Bing1, YANG Wenjie2,3, CHEN Xiao1, ZHANG Benjian1, XU Qiang2, LI Minglong2, XIAO Di2, QIAO Zhanfeng4, TAN Xiucheng2()   

  1. 1 PetroChina Southwest Oil and Gas Field Company,Chengdu 610051,China
    2 CNPC Key Laboratory of Carbonate Reservoirs Southwest Petroleum University Division,Chengdu 610500,China
    3 SINOPEC Exploration Company,Chengdu 610041,China
    4 Hangzhou Research Institute of Geology,PetroChina,Hangzhou 310023,China
  • Received:2025-02-14 Revised:2025-03-15 Online:2025-08-01 Published:2025-07-30
  • Contact: TAN Xiucheng,born in 1970,is a professor and Ph.D. advisor of Southwest Petroleum University. He is mainly engaged in researches on carbonate sedimentology and reservoir geology. E⁃mail: tanxiucheng70@163.com.
  • About author:

    WEN Long,born in 1977, holds a Ph.D. degree and is a senior engineer. He is mainly engaged in comprehensive geological research and management of natural gas exploration. E-mail:

  • Supported by:
    Key Project of the National Natural Science Foundation of China and the CNPC Joint Fund(U23B20154); General Project of the National Natural Science Foundation of China(42172166); Science and Technology Cooperation Project of the CNPC-Southwest Petroleum University Innovation Consortium(2020CX010000)

摘要:

中二叠世是四川盆地重要的构造转换期,因该时期多种构造共同作用,造成茅口组岩相古地理特征尚不明确,从而制约了有利储集相带预测。本研究通过对露头、钻井及地震资料的分析,厘清四川盆地茅口组沉积相类型,重建其构造-岩相古地理格局及演化过程。研究表明: (1)四川盆地茅口组主要发育8种岩石微相和9类典型微相组合序列,结合古生物、沉积构造等相标志,识别出碳酸盐岩缓坡和镶边碳酸盐岩台地2种沉积体系; (2)茅口组沉积时期主要分为3个构造-沉积演化阶段: (i)海西早期继承性古隆起发育期(SQ1-SQ2),四川盆地具有“西南高、东北低”的缓坡地貌格局,发育稳定的碳酸盐岩缓坡沉积环境,围绕川西南古隆起发育多带迁移性薄滩体; (ii)川北持续伸展期(SQ3-SQ5),勉略洋向北俯冲形成3期后撤式多级坡折带,导致川北地区逐级沉降为深水盆地,四川盆地出现显著的台-盆分异格局,沉积体系开始向镶边碳酸盐岩台地转变; (iii)地幔柱隆升-拉张期(SQ6),扬子西南缘峨眉山地幔柱隆升产生的远端拉张作用导致川西南坳陷带形成,这进一步加剧了四川盆地南部台地的分异,造成川西南地区向台内洼地演变; (3)茅口组孔洞型白云岩储集层和岩溶孔隙型灰岩储集层的分布均受古地貌和高能滩相控制,台缘滩和台内滩是茅口组储集层发育有利区带,其中后撤式多级坡折带控制的多期台缘滩带、环海西早期继承性古隆起的带状滩体、伸展背景下平行带状展布的台内滩带是茅口组滩相储集层的有利发育区。该研究重建了茅口组等时层序格架下的构造-岩相古地理格局,揭示有利储集相带分布规律,为茅口组油气规模发现提供方向。

关键词: 构造-岩相古地理, 沉积演化, 有利储集区, 茅口组, 二叠系, 四川盆地

Abstract:

The Middle Permian represents a crucial phase of structural transformation in the Sichuan Basin. Under the cumulative effects of various structural activities,the lithofacies palaeogeographic attributes of the Maokou Formation remain ambiguous,thereby hindering the prediction of favorable reservoir facies belts. By analyzing outcrop,drilling and seismic data,the sedimentary facies types of the Maokou Formation in the Sichuan Basin are clarified and the tectonic-lithofacies palaeogeographic pattern along with its evolution process are reconstructed. The results show that: (1)Eight types of rock microfacies and nine typical microfacies assemblage sequences have been identified in the Maokou Formation. Two sedimentary systems,specifically carbonate gentle slopes and marginal carbonate platforms,have been distinguished by integrating palaeontological and sedimentary tectonic markers. (2)The Maokou Formation underwent three stages of tectono-sedimentary evolution: the early Hercynian inheritable palaeouplift controlled the “southwest high and northeast low” landform pattern of the early Maokou(SQ1-SQ2),leading to the development of a stable carbonate gentle slope sedimentary environment,and the formation of a multi-zone migration thin beach body around the southwest Sichuan palaeouplift. Continuous extension in northern Sichuan resulted in the formation of a recessional multistage slope break zone,which led to significant platform-to-basin differentiation in the northern and southern parts of the basin,thereby directly controlling sedimentary differentiation during the middle and late Maokou(SQ3-SQ5). The sedimentary system transitioned into a marginal carbonate platform,with sedimentary facies zones exhibiting distinct northeast zoning characteristics. The uplift and stretching of the Emei plume led to the development of the southwest Sichuan depression belt,further intensifying the differentiation of the late Maokou(SQ6)platform,and causing the southwest Sichuan region to evolve into an inner depression. (3)The distribution of cavern dolomite reservoirs and karst pore limestone reservoirs in the Maokou Formation is controlled by sedimentary palaeogeomorphology and high-energy beach facies. The platform edge beach and inner beach facies represent favorable zones for reservoir development within the Maokou Formation. Key regions for the development of beach facies reservoirs include the platform margin beach zone in the Maokou Formation controlled by the retreating multistage slope break zone;the belt beach body surrounding the early inheriting paleo-uplift in the western rim;and the inner platform beach zone,which is distributed in parallel belts under an extensional setting. This study reconstructs the tectono-lithofacies palaeogeographic pattern of the Maokou Formation within a chronostratigraphic sequence framework,reveals the distribution patterns of favorable reservoir facies belts,and provides guidance for large-scale oil and gas discoveries in the Maokou Formation.

Key words: tectono-lithofacies palaeogeography, sedimentary evolution, favorable reservoir zone, Maokou Formation, Permian, Sichuan Basin

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