地学前缘 ›› 2023, Vol. 30 ›› Issue (6): 14-31.DOI: 10.13745/j.esf.sf.2023.2.15

• 深层-超深层碳酸盐岩储层形成环境、发育机理和成因模式 • 上一篇    下一篇

四川盆地震旦系灯影组二段葡萄-花边结构成因及其对储层控制作用

鲁鹏达1,2(), 李泽奇1,2, 田腾振1,2, 吴娟1,2, 孙玮1,2, 乔占峰3, 王永生3, 刘树根1,2,4, 邓宾1,2,*()   

  1. 1.成都理工大学 油气藏地质及开发工程国家重点实验室, 四川 成都 610059
    2.成都理工大学 能源学院, 四川 成都 610059
    3.中国石油杭州地质研究院, 浙江 杭州 310023
    4.西华大学, 四川 成都 610039
  • 收稿日期:2023-01-05 修回日期:2023-02-05 出版日期:2023-11-25 发布日期:2023-11-25
  • 通讯作者: * 邓宾(1980—),男,教授,博士生导师,主要从事含油气盆地分析与油气成藏研究工作。E-mail: dengbin13@mail.cdut.edu.cn
  • 作者简介:鲁鹏达(1997—),男,硕士研究生,主要从事碳酸盐岩储层研究。E-mail: lupengda1997@foxmail.com
  • 基金资助:
    国家自然科学基金项目“海相深层油气富集机理与关键工程技术基础研究(U19B6003);国家自然科学基金企业创新发展联合基金配套项目“四川盆地震旦系—寒武系油气成藏过程与机理(P19038)

The botryoidal-lace texture and its role in dolomite reservoir control in the 2nd member, Sinian Dengying Formation in Sichuan Basin

LU Pengda1,2(), LI Zeqi1,2, TIAN Tengzhen1,2, WU Juan1,2, SUN Wei1,2, QIAO Zhanfeng3, WANG Yongsheng3, LIU Shugen1,2,4, DENG Bin1,2,*()   

  1. 1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059, China
    2. College of Energy, Chengdu University of Technology, Chengdu 610059, China
    3. PetroChina Hangzhou Research Institute of Petroleum Geology, Hangzhou 310023, China
    4. Xihua University, Chengdu 610039, China
  • Received:2023-01-05 Revised:2023-02-05 Online:2023-11-25 Published:2023-11-25

摘要:

葡萄-花边结构是全球震旦系灯影组二段中发育的一种独特标志性沉积构造,其成因机制与沉积模式具广泛争议。四川盆地灯二段宏观-微观岩石学特征以及地球化学等研究表明:(1)四川盆地灯二段葡萄-花边结构是震旦纪“文石-白云石海”环境准同生期高频海平面波动下岩溶作用的产物,微生物岩在岩溶空间规模的非均质性最终决定着葡萄-花边结构形态分异特征,即形成不同形态的纤维状胶结物(FSD+FFD或FSD+RFD)。(2)葡萄状结构和花边状结构发育丰度与微生物岩组构(MM)之间存在明显相关性。其中葡萄状结构主要由束状正延性白云石(FSD)及束状负延性白云石(FFD)组成,通常发育在四级旋回基准面底部的颗粒白云岩和顶部的凝块石白云岩层段;花边状结构由束状正延性白云石和放射状负延性白云石(RFD)组成,主要发育在以四级旋回基准面中部的纹层-叠层石白云岩层段。因此,灯二段微生物岩组构纵向上多旋回特征和间歇性大气淡水溶蚀作用,共同形成了灯二段葡萄-花边优质白云岩储层的多级、立体结构。

关键词: 四川盆地, 灯影组, 碳酸盐岩, 微生物岩, 岩溶储层

Abstract:

The genesis and depositional environment of the unique botryoidal-lace dolomite in the 2nd member of the Sinian Dengying Formation are widely debated. Through detailed petrological and geochemical analyses we show that (1) the botryoidal-lace texture is formed by karst activities under high-frequency sea-level fluctuations quasi-contemporaneous with Sinian “aragonite-dolomite seas”, while the spatial heterogeneity of microbialite across the karst zone ultimately controls the textural differentiation to result in various fibrous dolomite cement types. (2) There is an obvious correlation between the botryoidal-lace texture and microbiolite matrix (MM) abundances. The botryoidal texture is mainly composed of FSDs (fascicular slow dolomite) and FFDs (fascicular fast dolomite), usually developed in sections of granular dolomite at the top and thrombolites dolomite at the bottom of the fourth-order cycles. The lace texture is composed of fascicular slow dolomite and RFDs (radial fast dolomite), mainly developed in the middle of the fourth-order cycles, in sections of laminated-stromatolites dolomite. Therefore, the longitudinal multi-spinulite feature and intermittent dissolution of microbialite by atmospheric water, together form the multi-stage, three-dimensional architecture of the high-quality botryoidal-lace dolomite in the Dengying Formation.

Key words: Sichuan Basin, Dengying Formation, carbonate, microbilite, karst reservoir

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