中国石油勘探 ›› 2025, Vol. 30 ›› Issue (1): 156-167.DOI: 10.3969/j.issn.1672-7703.2025.01.012

• 石油地质 • 上一篇    下一篇

中西非裂谷系油气成藏研究新进展与勘探启示

史忠生1,马峰1,庞文珠2,陈彬滔1,薛罗1,代寒松1,徐飞1,马轮1   

  1. 1 中国石油勘探开发研究院西北分院;2 中国石油国际勘探开发有限公司
  • 出版日期:2025-01-15 发布日期:2025-01-15
  • 作者简介:史忠生(1978-),男,辽宁沈阳人,博士,2006年毕业于中国地质大学(武汉),高级工程师,现主要从事裂谷盆地成盆机理与油气成藏研究。地址:甘肃省兰州市城关区雁儿湾路535 号中国石油勘探开发研究院西北分院油藏描述研究所,邮政编码:730020。
  • 基金资助:
    国家科技重大专项“海外重点探区目标评价与未来领域选区选带研究”(2016ZX05029005);中国石油天然气股份有限公司科学研究与技术开发项目“海外重点领域油气勘探关键技术”(2021DJ31)

New progress in the study of hydrocarbon accumulation and exploration insights in Central and Western African Rift System

Shi Zhongsheng1,Ma Feng1,Pang Wenzhu2,Chen Bintao1,Xue Juo1,Dai Hansong1,Xu Fei1,Ma Lun1   

  1. 1 PetroChina Research Institute of Petroleum Exploration and Development-Northwest; 2 China National Oil and Gas Exploration and Development Co., Ltd.
  • Online:2025-01-15 Published:2025-01-15

摘要: 中西非裂谷系发育众多含油气盆地,具有丰富的油气资源。通过对中西非裂谷系盆地走向与区域应力场方向对成盆控制作用、中西非裂谷系构造演化与烃源岩发育关系及不同方向裂谷盆地沉积充填与成藏模式的研究,展示了中西非裂谷系成盆、成烃、成藏最新研究进展,并通过对不同类型盆地成藏模式的研究与典型盆地勘探实践分析,明确了中西非裂谷系高效勘探的做法及未来勘探领域与方向。研究表明:盆地走向与区域应力场方向控制了中西非裂谷系发育多期叠置裂谷与单一裂谷两类盆地,其中NW—SE向盆地发育早白垩世、晚白垩世、古近纪多期裂谷作用,形成“源下储上、源上成藏”主要成藏模式,NE—SW 向盆地发育和保留早白垩世一期裂谷作用,形成下白垩统“源储一体、源内成藏”及下白垩统与基岩潜山构成的“源上储下、源下成藏”模式;中西非裂谷系不同的构造背景与地质演化过程决定了西非裂谷系发育上白垩统陆源海相烃源岩,中非裂谷系发育下白垩统陆相烃源岩,其厚层、优质、成熟烃源岩的发育,为中西非裂谷系油气富集提供了物质基础。Melut盆地勘探实践表明,快速锁定富油凹陷,围绕富油凹陷部署连片三维地震是海外油气项目实现高效勘探的关键,Termit、Melut等NW—SE向多期叠置裂谷盆地的源内成藏组合,以及Bongor、Doseo等NE—SW向单一裂谷盆地的源内岩性油藏及富油凹陷源外圈闭是中西非裂谷系未来勘探的重要领域与方向。

关键词: 成藏模式, 富油凹陷, 高效勘探, 源外油藏, 中西非裂谷系

Abstract: There are multiple petroliferous basins in Central and Western African Rift System (CWARS), with abundant oil and gas resources.Based on the study of the control of CWARS basins orientation and regional stress field direction on basin formation, relationship between tectonic evolution of CWARS and source rock development, as well as the sedimentary filling and hydrocarbon accumulation patterns of rift basins in different directions, the author presents the latest study progress of basin formation, hydrocarbon generation and hydrocarbon accumulation in CWARS. In addition, hydrocarbon accumulation patterns in various types of basins and exploration practice in typical basins are analyzed, which clarify the high-efficiency exploration practices and future exploration fields and orientations in CWARS. The study results show that, controlled by basin orientation and direction of regional stress field, multi-stage superimposed and single-stage rift basins were developed in CWARS. Among them, multi-stage rift processes occurred in NW–SE trending basins in the Early Cretaceous, Late Cretaceous,and Paleogene, forming the main hydrocarbon accumulation pattern of “lower source rock and upper reservoir, and hydrocarbon accumulation above source rock”. While a single-stage rift process experienced in the NE–SW trending basins in the Early Cretaceous, forming hydrocarbon accumulation patterns of “integrated source rock and reservoir, and hydrocarbon accumulation inside source rock” in the Lower Cretaceous and “upper source rock and lower reservoir, and hydrocarbon accumulation below source rock” in the Lower Cretaceous and buried hill.The diverse tectonic settings and geological evolution processes determined that terrigenous marine source rock was developed in the Upper Cretaceous in Western African Rift System and continental facies source rock was developed in the Lower Cretaceous in Central African Rift System. The thick, high-quality and mature source rocks provided a material basis for hydrocarbon enrichment in CWARS. The exploration practice in Melut Basin indicates that the key to achieving the high-efficiency exploration of overseas oil and gas projects relies on the rapid identification of oil-rich sags and the subsequent deployment of connected 3D seismic data. The major fields and orientations for the future exploration in CWARS include intra-source rock hydrocarbon accumulation combination in NW-SE trending multi-stage superimposed rift basins such as Termit and Melut, intra-source rock lithological oil reservoirs in NE-SW trending single-stage rift basins such as Bongor and Doseo, as well as traps outside source rock in oil-rich sags.

Key words: hydrocarbon accumulation pattern, oil-rich sag, high-efficiency exploration, outside source rock play, Central and Western African Rift System

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