摘要
阳江凹陷为珠江口盆地近两年来获得油气勘探重大突破的新区。为明确阳江凹陷恩平21洼烃源岩的生烃潜力及成藏贡献,采用无机元素分析与有机地球化学分析相结合的研究方法,对阳江凹陷文昌组烃源岩的沉积环境、有机质来源及生烃潜力进行了系统分析,明确了已发现原油的来源并估算了不同沉积环境烃源岩的成藏贡献。结果表明:文昌组沉积时期恩平21洼气候湿热,湖盆水体较深、盐度较低,是整体处于亚还原环境的淡水湖盆,发育半深湖-深湖相和浅湖-半深湖相两套优质烃源岩;油-源对比及油藏中不同来源原油的占比分析发现,源于半深湖-深湖相烃源岩的占比为15%,源于浅湖-半深湖相烃源岩的占比为85%。浅湖-半深湖相烃源岩同样具有较强的供烃能力,发育浅湖-半深湖相烃源岩的浅-小洼陷,也具有较好的油气资源潜力。
Recently,Yangjiang Sag has become a new area that has made major breakthroughs in petroleum exploration in Pearl River Mouth Basin.To clarify the hydrocarbon generation potential and accumulation contribution of source rocks of Enping 21 Subsag in Yangjiang Sag,the sedimentary environment,source of organic matter,and hydrocarbon generation potential of source rocks of Wenchang Formation drilled in Yangjiang Sag were systematically analyzed,using methods combining inorganic element analysis with organic geochemical analysis in this paper.The sources of the discovered crude oil were identified and the accumulation contribution of source rocks in different sedimentary environments was estimated.The results show that Enping 21 Subsag is characterized by a humid-hot climate,and a deep freshwater lake basin with low salinity in a sub-reductive environment on the whole,and two sets of high-quality source rocks,including semi-deep to deep and shallow to semi-deep lacustrine source rocks,are developed during the deposition of Wenchang Formation.The oilsource correlation and the calculation of the proportion of crude oil from different sources in the reservoirs indicate that the crude oil from shallow to semi-deep lacustrine source rocks accounts for 85%,and that from semi-deep to deep source rocks only accounts for 15%.The shallow to semi-deep lacustrine source rocks also have strong hydrocarbon supply ability,and the shallow and small subsags developed with shallow to semi-deep lacustrine source rocks also have great petroleum resource potential.
作者
熊万林
龙祖烈
朱俊章
杨兴业
石创
翟普强
杜晓东
XIONG Wanlin;LONG Zulie;ZHU Junzhang;YANG Xingye;SHI Chuang;ZHAI Puqiang;DU Xiaodong(CNOOC China Limited,Shenzhen Branch,Shenzhen City,Guangdong Province,518054,China)
出处
《油气地质与采收率》
CAS
CSCD
北大核心
2021年第5期50-56,共7页
Petroleum Geology and Recovery Efficiency
基金
“十三五”国家科技重大专项“南海东部海域勘探新领域及关键技术”(2016ZX05024-004)。
关键词
沉积环境
生烃潜力
成藏贡献
烃源岩
阳江凹陷
珠江口盆地
sedimentary environment
hydrocarbon generation potential
accumulation contribution
source rock
Yangjiang Sag
Pearl River Mouth Basin
