中国石油勘探 ›› 2020, Vol. 25 ›› Issue (4): 43-51.DOI: 10.3969/j.issn.1672-7703.2020.04.005

• 石油地质 • 上一篇    下一篇

非洲地区裂谷盆地类型及油气成藏特征

张光亚1 ,余朝华1,2 ,黄彤飞1 ,程顶胜1 ,陈忠民1 ,陈曦1 ,刘红1 ,宋成鹏1 ,   

  1. 1 中国石油勘探开发研究院;2 中国石油国际勘探开发有限公司
  • 出版日期:2020-07-14 发布日期:2020-07-14
  • 基金资助:
    中国石油天然气股份有限公司科技专项“全球油气资源评价与利用研究”(2013E-0501),中国石油天然气集团有限公司 科学研究与技术开发项目“南苏丹—苏丹重点盆地勘探领域评价与目标优选”(2019D-4306)。

Types of rift basins in Africa and their hydrocarbon accumulation characteristics

Zhang Guangya1, Yu Zhaohua1,2, Huang Tongfei1, Cheng Dingsheng1, Chen Zhongmin1, Chen Xi1, Liu Hong1, Song Chengpeng1   

  1. 1 PetroChina Research Institute of Petroleum Exploration & Development; 2 China National Oil and Gas Exploration and Development Corporation Ltd.
  • Online:2020-07-14 Published:2020-07-14
  • Supported by:
     

摘要: 非洲地区发育多期多类裂谷盆地,油气资源丰富。为指导非洲地区油气勘探与战略选区,对非洲地区裂 谷盆地形成期次、类型及重点裂谷盆地的油气成藏特征进行了分析和研究。研究结果表明:①非洲地区主要发育古生 代、中生代和新生代3 期裂谷盆地,形成卡鲁裂谷系、中西非陆内裂谷系、北非陆缘裂谷系及红海—亚丁湾—东非裂 谷系;按原型盆地成因,可划分为与热隆拉张有关的主动裂谷盆地以及与走滑或区域伸展应力场有关的被动裂谷盆地; 根据盆地所处构造位置及基底特征,可划分为陆内裂谷盆地、陆间裂谷盆地、拗拉谷裂谷盆地和陆缘裂谷盆地。②因 盆地构造演化、沉积充填和结构的不同,导致油气地质特征及油气富集规律存在差异。北非陆缘裂谷盆地发育海相优 质烃源岩,以中—新生界含油气系统为主,油气主要富集在差异沉降形成的断垒区;中西非陆内裂谷盆地多期裂谷叠 置,主力成藏组合存在较大差异,油气主要分布在古近系、上白垩统、下白垩统不同层系中;东非陆内裂谷盆地形成 晚,以新生界含油气系统为主。

 

关键词: 非洲板块, 裂谷盆地, 主动裂谷, 被动裂谷, 油气地质

Abstract: Rift basins in Africa are of many types, are in many stages of geological development, and often possess rich oil and gas resources. In order to guide oil and gas exploration and strategic selection of favorable areas, this study analyzes the types and formation stages of rift basins in Africa. The hydrocarbon accumulation characteristics of a number of key rift basins are also described. The results show that: (1) there are three principal stages of rift basins in Africa: Paleozoic, Mesozoic, and Cenozoic. A number of rift systems are formed: the Karoo rift system, the intracontinental rift system in West and Central Africa, the continental margin rift system in North Africa, and the Red Sea-Gulf of Aden-East African rift system. Prototype basins can be divided into active rift basins and passive rift basins according to genesis type. Active basins are related to thermal-uplift and tension and passive basins are related to strike slip or regional extensional stress fields. Basins can be divided into intracontinental rift basins, intercontinental rift basins, aulacogen rift basins, and continental margin rift basins according to structural position and basement characteristics. (2) The basins have different petroleum geological characteristics and hydrocarbon enrichment laws as a result of variations in tectonic evolution, sedimentary filling, and structure. In North Africa, high-quality marine source rocks are developed in continental margin rift basins. The dominant petroleum system is a Mesozoic-Cenozoic system. Oil and gas are primarily accumulated in faulted horst areas formed by differential subsidence. In Central and West Africa, multi-stage superimposed rifts are developed in intracontinental rift basins with a variety of major plays. Oil and gas are distributed in Paleogene, Upper Cretaceous, and Lower Cretaceous formations. In East Africa, intracontinental rift basins formed late and are dominated by a Cenozoic petroleum system.

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