摘要
沉积物源分析是沉积体系分布研究中重要的基础性工作。溱潼凹陷阜三段是重要的油气勘探层系,由于盆地在戴南期地层发生翘倾改造,改变了阜三段原型盆地的产状,给沉积物源方向判别带来困难,影响了沉积体系格架预测和勘探方向评价部署。本文运用沉积学原理和地震地层学方法,综合利用多种资料分析了溱潼凹陷中部地区阜三段的沉积物源方向。结果表明:(1)在溱潼凹陷中部地区阜三段发现来自东南部泰州古凸起的大型沉积物源。(2)指出溱潼凹陷中部地区阜三段沉积期主要受到东南部物源的控制,强调该时期发育源自东南部物源区的大型三角洲沉积;溱潼凹陷阜三段沉积期发育东南部和北部主要物源,表现出多物源沉积充填特征。(3)认为溱潼凹陷属于多阶段演化和后期强烈改造的叠合盆地,盆地形态和性质发生了改变,后期改造导致了盆地翘倾,造成凹陷东部地区大幅度沉降与深埋,凹陷西部地区掀斜抬升与部分地层遭受剥蚀,沉积体系保存不完整,凹陷中部地区变成大型斜坡带,原始地层的前积现象转变为上超假象。(4)提出东南部物源三角洲前缘亚相发育区是有利的储集相发育带和岩性油气藏勘探有利区。上述新观点深化了溱潼凹陷阜三段沉积物源认识,对改造型叠合盆地沉积物源分析可提供有益的借鉴。
Sediment provenance analysis is a fundamental component in the study of sedimentary system distributions.The third member of the Funing Formation is a stratigraphic unit that is an important hydrocarbon exploration target.During the Dainan period,reformation of the depositional stratum because of the tilting of the basin caused a change in the geographic extent of the sedimentary basin of the third member of the Funing Formation,which changed the prototype basin and made determining the direction of sediment provenance difficult;this affects inference of the sedimentary system framework and the evaluation and deployment of exploration operations.Based on sedimentological principles and seismic stratigraphic methods,multiple methods were comprehensively used to analyze the direction of sediment provenance of the third member of the Funing Formation in the central part of the Qintong sag.The following conclusions were drawn:(1)Based on seismic and geological provenance synthesis analysis methods,a large sediment provenance from the southeastern Taizhou paleo-uplift was identified in the central part of the Qintong Sag.(2)The sediment in the central part of the Qintong Sag,controlled by the southeastern provenance during the depositional period of the third member of the Funing Formation,was identified;this large delta originated from the southeastern provenance area.The Qintong Sag was supplied by both the southeastern and northern provenances,which developed a sedimentary filling regime characterized by multiple provenances during the formation of the third member of the Funing Formation.(3)The Qintong Sag,considered to belong to a superimposed basin,was characterized by multi-stage evolution and late intense reformation:the paleo-topography and properties of the basin underwent changes,and late intense reformation resulted in the basin tilting.As a result,the eastern part of the sag subsided significantly and the depositional area of the southeastern provenance was deeply buried.In contrast,the western part of the sag was uplifted by the tilting,which led to partial denudation of the deposited stratum of the northern provenance and incomplete preservation of the sedimentary system.Additionally,the central part of the sag became a large sloping area,and progradation in the original stratum was transformed into an onlap.(4)The development area of the sedimentary subfacies of the delta front controlled by the southeastern provenance was considered to be the area possessing the most favorable conditions to host reservoir facies,and is therefore a favorable area for lithologic reservoir exploration.These new insights advance the identification of the sediment provenance of the third member of the Funing Formation in the Qintong Sag and provide a useful reference for sediment provenance analyses of the reformed and superimposed basin.
作者
姜锐
刘震
朱茂林
唐建信
吴公益
伍炜
JIANG Rui;LIU Zhen;ZHU Maolin;TANG Jianxin;WU Gongyi;WU Wei(College of Geosciences,China University of Petroleum(Beijing),Beijing 102249;State Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum(Beijing),Beijing 102249;Wuxi Research Institute of Petroleum Geology,SINOPEC,Wuxi,Jiangsu 214126;East China Oil and Gas Branch Company,SINOPEC,Nanjing,Jiangsu 210019;Taizhou Oil Production Plant,East China Oil and Gas Branch Company,SINOPEC,Taizhou,Jiangsu 225300)
出处
《地球学报》
北大核心
2026年第2期371-386,共16页
Acta Geoscientica Sinica
基金
国家重大科技专项“岩性油气藏成藏动力、临界条件与分布模式”(编号:2011ZX05001-001-004)资助。
关键词
沉积物源
溱潼凹陷
地震相
三角洲相
原型盆地
构造翘倾
sediment provenance
Qintong Sag
seismic facies
delta facies
prototype basin
tectonic tilting
