珠三坳陷珠江组一段沉积体系演化过程及其控制因素  

Evolutionary and controlling factors of sedimentary system in the First Member of the Zhujiang Formation in the Zhu Ⅲ Depression

作　　者：吴太霏 王华[1] 刘恩涛 陈林 张璐 陈思[1] 谢卫东 谷志宇 张启扬 WU Taifei;WANG Hua;LIU Entao;CHEN Lin;ZHANG Lu;CHEN Si;XIE Wei-dong;GU Zhiyu;ZHANG Qiyang(School of Earth Resources,China University of Geosciences(Wuhan),Wuhan 430074,China;College of Marine Science and Technology,China University of Geosciences(Wuhan),Wuhan 430074,China;Zhanjiang Branch of CNOOC China Limited,Zhanjiang Guangdong 524057,China)

机构地区：[1]中国地质大学(武汉)资源学院,武汉430074 [2]中国地质大学(武汉)海洋学院,武汉430074 [3]中海石油(中国)有限公司湛江分公司,广东湛江524057

出　　处：《地质科技通报》2024年第2期111-122,共12页Bulletin of Geological Science and Technology

基　　金：国家自然科学基金项目“浅海外陆架海底扇-水道重力流发育机制与储层非均质性表征”(2017ZX05035004);“中国海油南海油气资源院士工作站”支持。

摘　　要：珠江组一段沉积时期是珠三坳陷沉积体系演变的重要时期,由早期的大范围三角洲沉积体系演化为晚期的浅海陆架沉积体系,对其演化过程及控制因素展开研究,不仅有利于揭示海侵过程中沉积体系演化过程,而且对浅海陆架有利沉积相带预测具有指导意义。综合利用岩心、测井以及高分辨率三维地震资料,建立了珠三坳陷珠江组一段四级层序地层格架,通过地质-地球物理结合方法查明了珠江组一段沉积体系的时空演化特征,并讨论了沉积演化的主控因素。研究表明:珠三坳陷珠江组一段可划分为PS1、PS2、PS3、PS4共4个四级层序。PS3和PS4时期主要发育三角洲前缘沉积,具有水下分流河道、分流间湾、河口坝和远砂坝等沉积微相组合;PS1和PS2时期以浅海陆架沉积体系大规模发育为特征,在研究区西部发育潮流砂脊,东部发育滨外砂坝。珠三坳陷沉积体系的平面展布以及垂向演化受相对海平面变化、物源供给强度、构造沉降与古地貌等综合控制。水下分流河道、潮流砂脊与滨外砂坝等微相砂岩占比高且物性好,为油气储集的有利沉积相带。[Objective] The First Member of the Zhujiang Formation in the Zhu Ⅲ Depression underwent significant changes in its sedimentary system.It transitioned from a large-scale delta system to a shallow sea shelf system.Understanding the evolutionary process and controlling factors of this basin is important for studying the sedimentary system during transgression and predicting favorable sedimentary facies zones on shallow sea shelves.[Methods] In this study,we used core,well logging,and high-resolution 3D seismic data to establish a stratigraphic framework for the First Member of the Zhujiang Formation.By combining geology and geophysics,we determined the temporal and spatial evolution characteristics of the sedimentary system and discussed the main controlling factors.[Results]Our findings show that the First Member of the Zhujiang Formation can be divided into four sequences:PS1,PS2,PS3,and PS4.PS3 and PS4 were dominated by delta deposits,including underwater distributary channels,estuarine dams,and distal dams.PS1 and PS2 were characterized by the development of large-scale shallow-sea shelf systems,with tidal sand ridges in the west and offshore sand dams in the east.The evolution of the sedimentary system in the Zhu Ⅲ Depression is influenced by sea level changes,source supply intensity,structural subsidence,and paleogeomorphology.[Conclusion]Microfacies sandstones,such as underwater distributary channels,tidal sand ridges,and coastal sand dams,have high percentages and good physical properties,making them favorable sedimentary facies zones for oil and gas reservoirs.

关 键 词：沉积体系 控制因素 珠江组一段 珠三坳陷 珠江口盆地 浅海陆架 层序地层 

分 类 号：P618.130.2[天文地球—矿床学]