大型三角洲-深水沉积盆地油气地质与成藏特征比较分析

1.中海油研究总院,北京 100028; 2.中海油有限公司勘探部,北京 100028

三角洲-深水沉积; 马哈坎三角洲; 尼罗河三角洲; 刚果扇; 油气成藏; 勘探潜力

A comparative analysis of hydrocarbon geology and reservoir formation characteristics of large delta-deepwater basin
HU Xiao-lin1,ZHAO Yang1,CAO Xiang-yang1,LI Dong1,LIU Xin-ying1,LIU Shen-yan2

(China)Co.,Ltd.,Beijing 100028,China)

delta-deepwater deposition; Mahakam Delta; Nile Delta; Congo Fan; hydrocarbon accumulation; exploration potential

DOI: 10.13800/j.cnki.xakjdxxb.2017.0312

备注

三角洲-深水沉积体系是世界上大中型油气田形成的重要场所,独特的沉积环境为油气生成和聚集提供了良好的生储盖与圈闭条件,不同的构造与沉积背景具有不同的成藏特点。为进一步研究该类盆地成藏特征与油气分布规律,指导油气勘探,特选取马哈坎三角洲盆地、尼罗河三角洲盆地和刚果扇盆地3个世界级富含油气区,采用比较分析的研究方法,通过对盆地构造与沉积演化、沉积特点、烃源岩、成藏组合及油气成藏特征等方面对比分析,对3个类型的大型三角洲-深水沉积盆地的油气地质与成藏特征进行总结。结果 表明,3大盆地均形成于被动大陆边缘稳定沉积背景,均发育了规模巨大的三角洲-深水沉积体系,石油地质条件非常优越; 由于形成时期不同的古气候、古沉积与古构造条件,3大盆地在沉积模式、烃源岩、主要成藏组合、油气类型、油气运移及油气藏类型等方面又具有明显差异性; 其未来主要勘探领域与勘探方向亦不同,马哈坎三角洲盆地以深水为主,尼罗河三角洲盆地以深层为主,刚果扇盆地以深水中浅层为主。

Delta-deepwater depositional system is an important place for the formation of mid-large oil and gas fields in the world.Its unique sedimentary environment provides good source-reservoir-cap and trap conditions for the generation and accumulation of hydrocarbon,but the basins show different characteristics for different structural and sedimentary backgrounds.In order to further study these basins' hydrocarbon accumulation and distribution characteristics,taking the Mahakam Delta basin,the Nile Delta Basin and the Congo Fan basin as examples,by using the method of comparative analysis,the structural and sedimentary evolution,sedimentary feature,source rock,reservoir accumulation assemblage and accumulation characteristics of the three delta-deepwater basin were compared.The results show:The three basins are formed in the background of stable passive continental margin,develop large scale delta-deepwater sedimentary system with excellent petroleum geological conditions; however,because of the different paleoclimate,paleo-sedimentary and paleo-tectonic conditions during formation,the sedimentary models,hydrocarbon source rocks,main reservoir accumulation assemblages,oil and gas types,oil and gas migration,and types of oil and gas reservoirs are obviously different in these three basins; the main exploration target and exploration direction in the future are also different,which the Mahakam delta basin is mainly focused on deepwater sediments,and the Nile delta basin is focused on deep layers and the Congo fan basin is focused on shallow layers of deepwater sediments.