摘要
珠江口盆地开平凹陷经过近40年的勘探,近期在深水区开平11-4构造的古近系中获得了大—中型轻质油油田的重大发现。为进一步指导开平凹陷的油气勘探,对开平11-4构造内的烃源、储层、圈闭、保存和运移等石油地质条件开展了深入研究,总结了油气成藏模式。研究表明:开平凹陷的地质结构为一个北断南超的拆离型复式半地堑;其文昌组发育优质半深湖—深湖亚相烃源岩,生烃潜力大;恩平组的浅水辫状河三角洲前缘沉积发育有利储-盖组合;早期的构造活动形成了断块、断背斜、断鼻等多种圈闭类型,而晚期构造活动弱,有利于油气保存;继承性的通源断裂为油气提供了垂向运移通道,油气通过"源-断-储"体系输导成藏;油藏自17 Ma以来经历了多期持续充注,具有"湖相优质烃源供烃、近源断层强充注、多期多层成藏"的成藏模式。开平11-4构造内大—中型轻质油油田的发现实现了开平凹陷新区勘探的突破,同时也是南海东部海域深水区古近系原油勘探的突破,展示出珠江口盆地深水区油气勘探前景广阔,对南海北部深水区的含油气盆地勘探具有重要借鉴意义。
After nearly 40 years of exploration in Kaiping sag of Pearl River Mouth Basin,a medium to large light oil field has been discovered in deep-water Paleogene strata of Kaiping11-4 structure.To further guide oil-gas exploration in Kaiping sag,the paper deeply investigates the petroleum geological conditions such as hydrocarbon sources,reservoirs,traps,preservation and migration conditions in Kaiping11-4 structure,and summarizes the oil and gas accumulation mode.The geological structure of Kaiping sag is a detachment-type compound half-graben with faults in the north and overlaps in the south.In Kaiping sag,Wenchang Formation develops high quality semi-deep to deep lacustrine source rocks with great hydrocarbon generation potential,and the shallow-water braided delta front deposits of Enping Formation develop a favorable reservoir-cap assemblage.The traps formed under the early tectonic activities are various,including faulted block,faulted anticline and plunging anticline,while the weak tectonic activity in the late period is conducive to oil and gas preservation.The inheritance faults that cut through the source rocks provide vertical migration channels so that oil and gas can be transported through the"source-fault-reservoir"system.The reservoirs in Kaiping11-4 structure have undergone multi-phase continuous charging since 17 Ma,presenting a hydrocarbon accumulation mode with the characteristics of"hydrocarbon supplying from high-quality lacustrine sources,strongly charging through near-source faults,and enriching in multiple stages and levels".The discovery of medium to large light oil field in Kaiping11-4 structure is not only a breakthrough of the new area exploration in Kaiping sag,but also a breakthrough of the Paleogene crude oil exploration in the eastern deep-water area of the South China Sea.It shows that the deep-water area of Pearl River Mouth Basin has a broad prospect for oil and gas exploration,and is of great significance to the exploration of petroliferous basins in the northern deep-water area of
作者
高阳东
彭光荣
陈兆明
姜大朋
马宁
李潇
吕华星
高中亮
Gao Yangdong;Peng Guangrong;Chen Zhaoming;Jiang Dapeng;Ma Ning;Li Xiao;LüHuaxing;Gao Zhongliang(Exploration and Development Department of CNOOC China Limited,Beijing 100010,China;Shenzhen Branch,CNOOC China Limited,Guangdong Shenzhen 518054,China)
出处
《石油学报》
EI
CAS
CSCD
北大核心
2023年第7期1029-1040,共12页
Acta Petrolei Sinica
基金
中海石油(中国)有限公司"十四五"科技攻关项目"南海深水区中深层规模有效碎屑岩储集体识别及预测技术"(KJGG2022-0102)资助。
关键词
珠江口盆地
开平凹陷
轻质油
湖相烃源
源-断-储
成藏模式
Pearl River Mouth Basin
Kaiping sag
light oil
lacustrine source
source-fault-reservoir
accumulation mode
