石油学报 ›› 2017, Vol. 38 ›› Issue (10): 1168-1182.DOI: 10.7623/syxb201710007

• 地质勘探 • 上一篇    下一篇

下刚果盆地Madingo组海相烃源岩岩相特征和沉积模式

黄兴1,2, 杨香华1,2, 朱红涛1,2, 康洪全3, 贾建忠3, 王波1,2, 季少聪1,2   

  1. 1. 中国地质大学构造与油气资源教育部重点实验室 湖北武汉 430074;
    2. 中国地质大学资源学院 湖北武汉 430074;
    3. 中海油研究总院 北京 100028
  • 收稿日期:2017-03-11 修回日期:2017-08-05 出版日期:2017-10-25 发布日期:2017-11-02
  • 通讯作者: 杨香华,男,1964年12月生,1987年获武汉地质学院石油系学士学位,2001年获中国地质大学(武汉)资源学院博士学位,现为中国地质大学(武汉)资源学院教授,主要从事沉积学、层序地层学及储层预测方向的教学与科研工作.Email:xhyang111@vip.sina.com
  • 作者简介:黄兴,男,1989年3月生,2012年获长江大学勘查技术与工程专业学士学位,现为中国地质大学(武汉)矿产普查与勘探专业硕士研究生,主要从事盆地沉积学、层序地层学及储层预测方向的研究工作.Email:huangxing0315@yeah.net
  • 基金资助:

    国家重大科技专项(2016ZX05032-001)资助。

Lithofacies characteristics and sedimentary pattern of Madingo Formation marine hydrocarbon source rocks in Lower Congo Basin

Huang Xing1,2, Yang Xianghua1,2, Zhu Hongtao1,2, Kang Hongquan3, Jia Jianzhong3, Wang Bo1,2, Ji Shaocong1,2   

  1. 1. Key Laboratory of Tectonics and Petroleum Resources of the Ministry of Education, China University of Geosciences, Hubei Wuhan 430074, China;
    2. Faculty of Earth Resources, China University of Geosciences, Hubei Wuhan 430074, China;
    3. CNOOC Research Institute, Beijing 100028, China
  • Received:2017-03-11 Revised:2017-08-05 Online:2017-10-25 Published:2017-11-02

摘要:

通过薄片镜下观察、扫描电镜、X射线衍射和常微量元素测量等分析结果,根据细粒沉积物矿物组成、岩石组构、微古生物与典型矿物特征,在下刚果盆地Madingo组海相烃源岩中识别出了6种烃源岩岩相:粉砂质细粒岩相、富放射虫细粒岩相、磷质细粒岩相、富有孔虫细粒岩相、灰质细粒岩相(灰泥)和黏土质细粒岩相。细粒沉积物岩相、微古生物化石、微常量元素和地震资料综合分析表明Madingo组海相烃源岩中发育含生物硅的生物沉积、含磷酸岩质的上升流沉积、富含硅质碎屑颗粒的悬浮沉积和粒序层理的底流沉积。下刚果盆地Madingo组海相烃源岩的沉积背景总体上属于裂后期陆架内部低能水介质条件下的还原环境,其沉积早期在大陆架内部发育半封闭—封闭的局限海环境,堆积了富含放射虫的优质烃源岩;Campanian期以后,区域地质背景转变为开阔陆架,发育与陆架上升流相关的富含磷酸盐与有孔虫的优质烃源岩。

关键词: 下刚果盆地, Madingo组, 岩相特征, 沉积作用, 沉积模式

Abstract:

Based on analyzing thin section by microscopic observation, scanning electron microscopy, X-ray diffraction as well as constant and trace element measurement, and considering the mineral composition of fine-grained sediment, lithologic fabric, micro-palaeontological characteristics and typical minerals, 6 types of hydrocarbon source rock lithofacies have been identified in marine source rocks of Madingo Formation:the silt fine-grained lithofacies, radiolarian enriched fine-grained lithofacies, phosphatic fine-grained lithofacies, foraminiferan enriched fine-grained lithofacies, cinereal fine-grained lithofacies (lime mud)and clayey fine-grained lithofacies. As demonstrated by the comprehensive analysis of fine-grained sediment lithofacies, micro-palaeontological fossils, constant and trace elements as well as seismic data, the biogenic deposit containing biosilicon, upwelling sediment containing phosphate rock, suspension sediment enriched with silicious clastic particles and bottom current sediment with graded bedding were developed in marine source rocks from Madingo Formation. As a whole, marine source rocks in Madingo Formation of the Lower Congo Basin were deposited under a reducing environment with low-energy water medium in post-rift continental shelf, and in the early deposition stage the semi-closed-closed restricted sea environment was developed in the continental shelf and the high-quality source rocks enriched with radiolarian were accumulated; and following the Campanian period, the regional geological background was converted to a wide continental shelf where high-quality source rocks enriched with phosphate and foraminiferan were developed due to upwelling on the continental shelf.

Key words: Lower Congo Basin, Madingo Formation, lithofacies characteristics, sedimentation, sedimentary pattern

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