摘要
在源—汇系统分析方法的指导下,以琼东南盆地古近系渐新统陵水组为例,基于海陆区域地质特征对比,利用露头、岩心、钻井、测井和三维地震资料,系统揭示陵水组沉积期“源、渠、汇”的特点,刻画源—汇系统分布格局,探讨其形成主控因素及油气地质意义。研究表明:(1)断拗转换期,琼东南盆地物源区整体呈“东西分块、南北分带”的分布特征,东部神狐隆起以印支期花岗变质岩为主,西部以燕山期花岗岩为主,盆内呈“南北新、中间老”的特点。(2)古沟谷、断槽、槽谷复合型等沟渠通道是研究区3种主要的输砂通道类型。(3)依据物源供给方式的差异程度,形成了断拗转换时期极具特色的外源型、内源型以及复合型等3类共生的源—汇系统。(4)物源、古地貌、海平面变化是断陷海盆断拗转换期源—汇系统特征的主控因素,其中物源岩性和规模决定沉积体的组成和规模;古地貌控制源区侵蚀强度和古水系的发育情况,进而影响了沉积体系的类型和分布;海平面升降变化不仅控制物源区的规模,还通过波浪和潮汐等海洋动力进一步调节沉积体的分布样式。(5)外源型源—汇系统易形成大型储集体,内源型源—汇系统因富含易溶矿物而促使次生孔隙发育,复合型源—汇系统则呈现储层物性区域差异。
Guided by the analysis of source-to-sink system,this study investigates the Paleogene Oligocene Lingshui Formation in the Qiongdongnan Basin by comparing the geological characterizes in land and sea areas and integrating outcrop,core,drilling,logging and 3D seismic data,to systematically analyze the characteristics of the source,transport pathway,and sink during the deposition of Lingshui Formation,and reveal the patterns,controlling factors and petroleum geologic significance of the source-to-sink systems.The results are obtained in five aspects.First,during the fault-depression transition,the Qiongdongnan Basin received sediments from the provenances presenting as segments in east-west and zones in north-south,primarily with the Indosinian granites in the Shenhu Uplift in the east and the Yanshanian granites in the west.Overall,the sources are young in the southern and northern parts and old in the interior of the basin.Second,three types of sediment transport pathways are identified:ancient valleys,fault troughs and transitional zones.Third,based on differences in sediment supply modes,the unique source-to-sink systems during the fault-depression transition in marine rift basins are categorized into three types:exogenous,endogenous and composite.Fourth,the characteristics of these source-to-sink systems are primarily controlled by provenance,paleogeomorphology,and sea-level changes.Provenance lithology and scale dictated the composition and volume of sedimentary deposits.Paleogeomorphology influenced erosion intensity in the provenance and the development of paleodrainage systems,thereby affecting the distribution and types of sedimentary systems.Additionally,sea-level changes decided the extent of the provenance,but also regulated the sediment distribution patterns through oceanic processes such as waves and tides.Fifth,the exogenous source-to-sink systems may form large-scale reservoir bodies,the endogenous systems develop secondary pores due to presence of soluble minerals,and the composite systems demonstrate reservoir properties varying from area to area.
作者
唐武
谢晓军
王雅宁
熊连桥
于进鑫
王诗琪
赵振
TANG Wu;XIE Xiaojun;WANG Yaning;XIONG Lianqiao;YU Jinxin;WANG Shiqi;ZHAO Zhen(CNOOC Research Institute Co.,Ltd.,Beijing 100028,China;College of Geosciences,Yangtze University,Wuhan 430100,China)
出处
《石油勘探与开发》
北大核心
2025年第5期1092-1103,共12页
Petroleum Exploration and Development
基金
国家自然科学基金联合基金项目“南海北部深水区深层温压场差异性演化对优质储层的控制机理”(U24B200849)
国家自然科学基金“南海深海地质演变对油气资源的控制作用”(91528303)。
关键词
源—汇系统
物源
古地貌
输砂通道
琼东南盆地
古近系
渐新统
陵水组
source-to-sink system
provenance
paleogeomorphology
sediment transport pathway
Qiongdongnan Basin
Paleogene
Oligocene
Lingshui Formation
