中西非裂谷盆地白垩系两类优质烃源岩发育模式  

Development pattern of two types of exceptional Cretaceous source rocks in the rift systems in West and Central Africa

作　　者：程顶胜[1] 窦立荣 张光亚[1] 刘邦[1] 宋换新[3] 刘计国[1] 毛凤军[1] 袁圣强[1] 胡瑛[1] CHENG Dingsheng;DOU Lirong;ZHANG Guangya;LIU Bang;SONG Huanxin;LIU Jiguo;MAO Fengjun;YUAN Shengqiang;HU Ying(Petrochina Research Institute of Petroleum Exploration and Development,Beijing,100083;China national oil and gas exploration and development corporation,Beijing,100034;Yangtze University,Wuhan,430100)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油国际勘探开发有限公司,北京100034 [3]长江大学,武汉430100

出　　处：《地质学报》2020年第11期3449-3460,共12页Acta Geologica Sinica

基　　金：国家专项“海外重点探区目标评价与未来领域选区选带研究”(编号2016ZX05029005);中国石油天然气集团有限公司“苏丹Muglad盆地精细勘探领域与目标优选”(编号2015D-0909);“南苏丹-苏丹重点盆地勘探领域评价与目标优选”(编号2019D-4306);“乍得-尼日尔重点盆地勘探领域评价和目标优选”(编号2019D-4308)联合资助的成果。

摘　　要：中西非裂谷系位于非洲中部,主要为沿中非剪切断裂带分布的被动裂谷盆地,进一步划分为中非裂谷系和西非裂谷系。针对国内外对勘探程度极低的中西非裂谷盆地白垩系优质烃源岩展布、发育机理及油气成藏模式认识薄弱的现状,笔者在开展大量中西非裂谷盆地上、下白垩统两类烃源岩样品的主微量元素等地球化学分析的基础上,从含油气盆地构造、烃源岩发育古环境、古气候、古生产力和有机质保存条件等分析出发,剖析了不同类型含油气盆地优质烃源岩发育主控因素,分别建立了中、西非裂谷系低勘探程度含油气盆地下白垩统、上白垩统优质烃源岩的发育模式:中非裂谷盆地(Bongor、Muglad、Melut盆地)下白垩统裂陷期快速沉降、温暖湿润气候条件下,勃发的水生有机质(藻类)控制的深水湖相优质烃源岩"生产力"单因素发育模式;西非裂谷盆地(Termit盆地)上白垩统拗陷期海侵、炎热潮湿气候条件下,陆源有机质输入为主,优越的保存条件(偏咸水体)优质海相烃源岩"生产力+保存条件"双因素控制的发育模式。从而进一步锁定富油气凹陷和主力成藏组合,有效指导含油气盆地内选区选带,助推油气规模储量发现。There are a series of rift basins in the rift systems of West and Central Africa that have developed along the Central Africa Shear Zone.These basins remain largely unexplored with little knowledge about the distribution and development pattern of Cretaceous source rocks of rift basins in West and Central Africa.On the basis of a large amount geochemical analytical data,including major and trace elements analysis,the authors discuss key factors for exceptional source rock development in different petroliferous basins from the following perspectives:petroliferous basin structure,paleoenvironment,paleoclimate,paleoproductivity,and degree of organic matter preservation.Finally,two types of development patterns of exceptional Cretaceous source rocks of rift basins in West and Central Africa rift systems have been established that can help us focus on rich oil depressions and main accumulation assemblages for new discoveries in different petroliferous basins.

关 键 词：中非裂谷盆地 西非裂谷盆地 白垩系 优质烃源岩 发育模式 

分 类 号：P618.13[天文地球—矿床学]