东非地区奥伽登盆地油气成藏要素及有利勘探区带分析  

Hydrocarbon accumulation factors and favorable exploration zone of Ogedan Basin,East Africa

作　　者：董玉文 陈旭[1] 欧荣生 曾凡成[3] DONG Yu-wen;CHEN Xu;OU Rong-sheng;ZENG Fan-cheng(Key Laboratory of Exploration Technologies for Oil and Gas Resources,Yangtze University,Caidian 430100,Hubei,China;Exploration Department of Qinghai Oilfield,China National Petroleum Corporation,Dunhuang 736202,Gansu,China;Institute of Geoscience,Yangtze University,Caidian 4301000,Hubei,China)

机构地区：[1]长江大学油气资源与勘探技术教育部重点实验室,湖北蔡甸430100 [2]青海油田公司勘探事业部,甘肃敦煌736202 [3]长江大学地球科学学院,湖北蔡甸430100

出　　处：《世界地质》2020年第3期590-600,共11页World Geology

基　　金：长江大学博士科研启动基金项目(802100270303)。

摘　　要：依据基础地质资料,结合最新的勘探进展,笔者简要分析东非奥伽登盆地烃源岩分布、储盖组合、圈闭特征和油气运聚等基本成藏要素,指出有利的勘探区带。结果表明:下三叠统Bokh组湖相泥岩厚度大(500~1500m)、在西南凹陷大面积分布(>10×104 km2)和有机质成熟度高的特征,构成大型油气田形成的物质基础。上二叠统到侏罗系发育Karoo群和Hamanlei群两套有利的储盖组合,圈闭类型以构造圈闭为主,少量岩性、地层圈闭和生物礁。勘探部署应该以西南部凹陷带周缘地区为突破口,中央隆起带目前有少量油气发现,具备稳定的构造背景,良好的油源、储盖和运移条件,为勘探突破的最有利区。The basic hydrocarbon accumulation factors of the Ogedan Basin including source rock distribution,reservoir-cap assemblage,trap characteristics,hydrocarbon migration and accumulation are briefly analyzed based on basic geological data and latest exploration progress,and the future favorable exploration zones are pointed out.The results show that the lacustrine mudstone in the Lower Triassic Bokh Formation constitutes the material basis for large oil and gas fields,with great thickness(500~1500 m),wide distribution in the southwest sag(>10×104 km 2)and high maturity of organic matter.From the Upper Permian to the Jurassic,two favorable reservoir and cap assemblages of Karoo and Hamanlei groups are developed.The effective traps mainly consist of structural traps,and a few lithologic-stratigraphic traps and organic reef.The exploration breakthrough is expected in the southwest hydrocarbon generation center and surrounding areas.The central uplift belt has a small amount of oil and gas discovery so far,but is in stable tectonic background and possessing good oil source,reservoir-cap assemblage and migration conditions,which is the most promising exploration area.

关 键 词：油气地质条件 成藏组合 奥伽登盆地 勘探靶区 

分 类 号：P618.13[天文地球—矿床学]