东海盆地西湖凹陷南部花港组上段浅水曲流河三角洲发育特征  

Shallow meandering river delta in the Huagang Formation in the southern Xihu Sag,East China Sea Basin

作　　者：陈春峰 陈忠云 万延周 陈建文[2] 徐东浩 冯桢鸣 俞伟哲 姜雪 CHEN Chunfeng;CHEN Zhongyun;WAN Yanzhou;CHEN Jianwen;XU Donghao;FENG Zhenming;YU Weizhe;JIANG Xue(Shanghai Branch of CNOOC China Ltd.,Shanghai 200335,China;Ministry of Land and Resources,Qingdao Institute of Marine Geology,Qingdao 266237,China)

机构地区：[1]中海石油(中国)有限公司上海分公司,上海200335 [2]中国地质调查局青岛海洋地质研究所,青岛266237

出　　处：《海洋地质与第四纪地质》2024年第6期175-185,共11页Marine Geology & Quaternary Geology

基　　金：中海石油(中国)有限公司上海分公司科技项目“西湖凹陷构造运动对大型圈闭发育和大规模油气运聚的控制”。

摘　　要：针对东海盆地西湖凹陷南部花港组上段H5及H4砂组沉积相研究中的难点,本文建立了针对浅水三角洲划分相带的新方法及研究流程,即“单井定相-平面描砂-寻岸划线-分区划带”。研究区具有形成浅水曲流河三角洲的地质条件并形成了独特的不同相带交互沉积区,在花港组上段H5及H4砂组沉积时期,盆内地形宽缓,丰水期与枯水期频繁交替出现,形成了研究区中部三角洲平原相沉积和三角洲前缘相沉积在较小的沉积旋回内交替出现。在丰水期,研究区中部以三角洲前缘相、浅湖相沉积为主,在枯水期,研究区中部以三角洲平原相沉积为主。以浅水曲流河三角洲沉积模式为指导,在研究区中部识别了大量河道砂体,这些砂体与该区的大型构造脊相迭合形成了众多有勘探潜力的构造-岩性复合圈闭,其中部分圈闭经钻探获得了油气发现。In response to the difficulties in studying the sedimentary facies of the H5 and H4 sand formations in the upper section of the Huagang Formation in the southern Xihu Sag of the East China Sea Basin,we established a new method and process for dividing facies zones in shallow water deltas,namely"single well facies determination-planar sand tracing-shoreline tracing-zoning and delineation"using seismic data and core data.Results shows that the study area had the geological background for the formation of shallow meandering river delta,in which a unique alternating sedimentary zone of different facies were formed.During the deposit period of the H5 and H4 sand groups,the terrain in the basin was wide and gentle,and water level changed frequently between flood season and dry season,resulting in the alternating deposits of delta plain facies and delta front facies in a short period in the central part of the study area.In the flood season,delta front and shallow lake sediments developed in the central part of the study area,while in dry season,delta plain developed.Under the guide of sedimentary model of shallow meandering river delta,many of river channel sand bodies were found in the central part of the study area.The channel sandstone bodies overlap on the large anticline structures,forming numerous litho-structural composite traps with great exploration potential.The research results were confirmed by new oil and gas discoveries.

关 键 词：浅水曲流河三角洲 交互式沉积 砂体展布 西湖凹陷 花港组 

分 类 号：P736[天文地球—海洋地质]