东非大陆边缘穆伦达瓦盆地成藏模式及在油气勘探中的应用  

Hydrocarbon Accumulation Model of Morondava Basin on East Africa Continental Margin and Its Application in Oil and Gas Exploration

作　　者：臧晓琳 逄建东 王震 朱泽栋 孔为 Zang Xiaolin;Pang Jiandong;Wang Zhen;Zhu Zedong;Kong Wei(Engineering Technology Company of CNOOC Energy Technology&Services Limited,Tianjin 300450)

机构地区：[1]中海油能源发展股份有限公司工程技术分公司,天津300450

出　　处：《中外能源》2023年第10期37-44,共8页Sino-Global Energy

摘　　要：穆伦达瓦盆地历经一个世纪的油气勘探,除发现两个非常规油田外,还获得了6个常规油气田发现,但都不具有商业开采价值。盆地是否具备形成大中型油气田的条件,是投资者亟待解决的关键问题。在盆地演化、油气成藏条件分析的基础上,借鉴海域油气勘探的经验,建立穆伦达瓦盆地油气成藏模式。认识到穆伦达瓦盆地东部Sakamena次盆Karoo裂谷期烃源岩较为证实,且发育优质砂岩储层,已经发现的断裂背斜、断裂鼻状构造、断块等构造圈闭是盆地以往油气勘探的主要层系,以Bemolanga油砂、Tsimiroro重油为代表。其次盆地中部浅海陆架区上白垩统砂岩也发现两个常规油气田,但是产量低,不具有商业开发价值。而海域除了发育构造圈闭外,最重要的圈闭类型就是重力流相关的深切谷复合体、深水扇叶状复合体岩性圈闭,这将是今后盆地商业性油气勘探的主要方向。After a century of oil and gas exploration in the Morondava Basin,apart from the discovery of two unconventional oil fields(Bemolanga oil sands and Tsimiroro heavy oil),six conventional oil and gas fields were discovered,but none of them have commercial mining value.Whether the basin has the conditions to form large and medium-sized oil and gas fields is a key issue that investors need to solve urgently.Based on the analysis of basin evolution and hydrocarbon accumulation conditions,hydrocarbon accumulation model of the Morondava Basin is established drawing on the experience of offshore oil and gas exploration.It is known that the source rocks of the Karoo rift period in the Sakamena sub-basin in the eastern Morondava Basin are relatively confirmed,and high-quality sandstone reservoirs developed.Structural traps such as fault anticlines,fault nose structures,and fault blocks are the main strata of the basin in the past oil and gas exploration,represented by Bemolanga oil sands and Tsimiroro heavy oil.Secondly,two conventional oil and gas fields have been discovered in the Upper Cretaceous sandstones in the shallow sea shelf area in the central basin,but their production is low and there is no commercial development value.In addition to the development of structural traps,the most important trap types in the sea area are gravity flow-related deep-cut valley complexes and deep-water fan leaf shaped complex lithologic traps,which will be the main direction for commercial oil and gas exploration in the Morondava Basin in the future.

关 键 词：穆伦达瓦盆地 成藏模式 Karoo裂谷 浅海陆架区 重力流 深水扇 

分 类 号：P618.13[天文地球—矿床学]