›› 2013, Vol. 34 ›› Issue (5): 1-1.

• 论文 •    

西非被动大陆边缘盆地大油气田形成条件分段对比

温志新1,万仑坤1,吴亚东2,贺正军1,汪永华1   

  1. (1.中国石油 勘探开发研究院,北京 100083;2.中国石油集团 勘探开发公司,北京 100083)
  • 出版日期:2019-01-01 发布日期:1905-07-13

Formation Conditions and Segment Corelation of the Giant OilGas Fields in Passive Continental Margin Basins in West Africa

WEN Zhixin1, WAN Lunkun1, WU Yadong2, HE Zhengjun1, WANG Yonghua1   

  1. (1.Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China; 2.Oil and Gas Exploration and Development Corporation, CNPC, Beijing 100083, China)
  • Online:2019-01-01 Published:1905-07-13

摘要: 以板块学说为理论基础,利用多渠道资料来源,研究了西非沿海原型盆地形成演化过程,分段对比了古沉积环境变化及其对大油气田形成条件的控制作用,建立了“三段”“四类”盆地大油气田成藏模式。研究认为,“三段”盆地都经过了陆内裂谷、过渡期陆间裂谷及漂移期被动大陆边缘3个原型阶段,南段“裂谷层系发育型”盆地由于被动陆缘层系不发育,形成“裂谷层系构造-地层型”大油气田成藏模式;中段含盐型盆地以过渡期陆间裂谷盐岩充填为特征,其上、下的漂移期海相及裂谷期湖相沉积均可形成优质烃源岩,盐岩及海相页岩作为优质盖层,形成了“双源-双盖型”成藏模式;北段转换型盆地漂移期海相沉积厚度大,“窄”陆棚、“陡”陆坡型盆地边缘形成了“漂移期浊积砂体群型”成藏模式。尼日尔高建设三角洲盆地形成了独特的“三角洲基浊积砂体型”成藏模式,内环滚动背斜带油气最富集,中环泥运动背斜带、外环逆冲挤压背斜带的浊积砂体中都有大油气田发现。

Abstract: Based on plate tectonics theory and various useful information or data, this paper presents the formation and evolution procedures of the coastal prototype basins in West African, the stage correlation of paleo?sedimentary environment changes and their controlling effects on the giant oil?gas fields’formation conditions, and develops the hydrocarbon accumulation modes for the giant oil?gas fields in such three stages and four types of basins. It suggests that the three? segment basins in this area underwent three prototype stages such as the Late Jurassic?Early Cretaceous intra?continental rift stage, the Early Cretaceous intercontinental rift as a transition stage and the Early Cretaceous passive continental margin as a drift stage in West Africa. In the south segment formed the rift sequence structural?lithologic mode, due to little passive continental margin sequence; in the middle segment, the salt?bearing basins were characterized by transitional intercontinental rift halite, with the upper and the lower drift marine and rift lagoonal sediments which are all as premium source rocks,whereas the halite and marine shale as premium cap rocks, forming“dual?source and dual?seal”mode; in the north segment, the transitional basins were of great thickness of drift marine sediments, where narrow shelf and steep slope gave rise to drift turbidite sand bodies mode. Also, Niger delta basin with the unique high construction base formed“delta turbidite sand body”mode, in which the inner?ring rolling anticline belt is of the richest oil and gas, and giant oil?gas fields have been found in the turbidite sand bodies in the central anticline belt with muddy anticline belt and the outside?ring thrust and compressional anticline belt

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