地学前缘 ›› 2025, Vol. 32 ›› Issue (5): 28-37.DOI: 10.13745/j.esf.sf.2024.12.81

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晚二叠世长兴期四川盆地构造格局及油气地质意义

陈友智1(), 臧殿光1, 胡刚2,*(), 冯许魁3, 王晓阳4, 肖东1, 陈颖5, 徐敏1, 梁虹1, 吴育林1, 陈辉1, 郭海洋1, 赵振伟1, 郭双1, 周跃宗1, 陶俊6   

  1. 1.中国石油集团东方地球物理勘探有限责任公司西南物探研究院, 四川 成都 610213
    2.中国地震局地球物理研究所, 北京 100081
    3.中国石油集团东方地球物理勘探有限责任公司, 河北 涿州 072750
    4.中国石油集团东方地球物理勘探有限责任公司西南物探分公司, 四川 成都 610213
    5.中国石油集团西南油气田公司开发事业部, 四川 成都 610000
    6.中国石油集团测井有限公司, 重庆 400000
  • 收稿日期:2024-04-01 修回日期:2024-12-14 出版日期:2025-09-25 发布日期:2025-10-14
  • 通信作者: 胡刚
  • 作者简介:陈友智(1982—),男,博士,高级工程师,主要从事地震构造解释与盆地分析方面的研究工作。E-mail: cugchenyz@126.com
  • 基金资助:
    中国石油东方地球物理公司油气勘探新领域综合研究项目;贵州省科技计划项目(黔科合支撑[2022]一般238)

Tectonic framework and oil-gas geological significance of Late Permian Changxing Period in Sichuan Basin

CHEN Youzhi1(), ZANG Dianguang1, HU Gang2,*(), FENG Xukui3, WANG Xiaoyang4, XIAO Dong1, CHEN Ying5, XU Min1, LIANG Hong1, WU Yulin1, CHEN Hui1, GUO Haiyang1, ZHAO Zhenwei1, GUO Shuang1, ZHOU Yuezong1, TAO Jun6   

  1. 1. BGP Southwest Geophysical Company, CNPC, Chengdu 610213, China
    2. Institute of Geophysics, China Earthquake Administration, Beijing 100081, China
    3. CNPC Geophysical Company Limited, Zhuozhou 072750, China
    4. BGP Southwest Geophysical Branch, CNPC, Chengdu 610213, China
    5. Development Division, PetroChina Southwest Oil & Gasfield Company, Chengdu 610000, China
    6. China National Logging Corporation, Chongqing 400000, China
  • Received:2024-04-01 Revised:2024-12-14 Online:2025-09-25 Published:2025-10-14
  • Contact: HU Gang

摘要:

晚二叠世长兴期四川盆地受多重构造体系影响,如何从盆山演化的角度来建立盆地构造格局与长兴组生物礁油气藏之间的关联,前人研究较少。在结合已有的大地构造研究成果的基础上,本文通过对四川盆地现有的地球物理、钻井和测井资料分析,建立了板块构造、盆地构造格局和生物礁成藏组合之间的成因联系。研究获得如下认识:(1)长兴期四川盆地北部和中南部分别受勉略洋构造演化和峨眉山地幔柱影响,此时基底NWW向断裂复活,拉张和走滑作用分别形成开江-梁平海槽和蓬溪-武胜台凹。(2)海槽东陡西缓,呈半地堑结构;台凹边界断裂均呈右行走滑,东侧边界断层叠覆区发育NEE和NW向断层,西侧边界断层弯曲处发育小型褶皱,台凹内部由边界断层走滑形成里德尔剪切组合P破裂,即NEE向断层。(3)海槽西侧陡坡带礁体沿边界断层垂向叠置,缓坡带礁体横向迁移;台凹东西两侧边界断层、内部NEE向断层附近和边界断层弯曲处褶皱核部发育礁体。(4)海槽和台凹边界断层沟通寒武系和二叠系烃源,附近长兴组礁体形成“下生上储”成藏组合,海槽台缘礁和同期海槽内部烃原岩形成“旁生侧储”;台凹内部NEE向断层沟通长兴组生物礁和龙潭组烃源形成“下生上储”;台凹边界断层弯曲处小型褶皱核部礁体缺少断层沟通下伏烃源,主要产水。(5)开江-梁平海槽和城口-鄂西海槽之间的川北地区,长兴期区域伸展方向与加里东期断层走向低角度相交,先存段复活形成张扭性断层,上升盘发育近东西向展布的生物礁。本文丰富了峨眉山地幔柱与古特提斯洋构造演化研究,并为长兴组生物礁滩油气勘探与开发提供了理论依据。

关键词: 四川盆地, 长兴期, 构造格局, 开江-梁平海槽, 蓬溪-武胜台凹, 油气藏, 生物礁

Abstract:

The Sichuan Basin during the Late Permian Changxing Period was influenced by multiple tectonic systems. However, few studies have established the correlation between the basin’s tectonic pattern and reef reservoirs from the perspective of basin and orogenic evolution. Based on previous geotectonic studies, this research establishes the genetic relationship between plate tectonics, basin tectonic patterns, and reef reservoir formation through analysis of geophysical and well-log data from the Sichuan Basin. The results show: (1) During the Changxing Period, the northern and southern parts of the Sichuan Basin were influenced by the tectonic evolution of the Mianlüe Ocean and the Emeishan mantle plume. Basement NWW-trending faults were reactivated, forming the Kaijiang-Liangping Trough and the Pengxi-Wushengtao Depression through extension and strike-slip, respectively. (2) The trough exhibits a semi-graben structure with a steep eastern flank and a gentle western flank. NEE- and NW-trending faults developed in the overlying area of the eastern boundary faults, while small folds developed at the bends of the western boundary faults. Strike-slip motion along the boundary faults within the depression formed a Riedel shear structure, including P-shears (NEE-trending faults). (3) Reefs on the steep western slope of the trough are stacked vertically along the boundary fault, whereas reefs on the gentle slope migrated laterally. Reefs also develop near the eastern and western boundary faults of the platform depression, near the internal NEE-trending faults, and in the cores of folds located at the bends of the boundary faults. (4) The boundary faults of the trough and depression connect with Cambrian and Permian hydrocarbon sources. Reefs in the nearby Changxing Formation form “lower-generation and upper-storage” accumulation assemblages. Reefs on the platform margin and source rocks within the trough form “side-generation and side-storage” assemblages. The NEE-trending faults within the platform connect Changxing Formation organic reefs with the Longtan Formation hydrocarbon source, forming a “lower-generation and upper-storage” assemblage. In contrast, reefs in the small fold cores at the bends of the platform depression boundary faults lack underlying fault-connected hydrocarbon sources and are predominantly water-bearing. (5) In the northern Sichuan area between the Kaijiang-Liangping Trough and the Chengkou-West Hubei Trough, the extension direction during the Changxing Period intersected at a low angle with pre-existing Caledonian faults, reactivating these fault segments and forming transtensional faults. This study enriches our understanding of the tectonic evolution related to the Emeishan mantle plume and the Paleo-Tethys Ocean, providing a theoretical basis for hydrocarbon exploration and development of reef-beach reservoirs in the Changxing Formation.

Key words: Sichuan Basin, Changxing Period, structure framework, Kaijiang-Liangping Trough, Pengxi- Wusheng Depression, oil and gas reservoir, reef

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