西湖凹陷中北部花港组上段浅水辫状河三角洲发育特征  

Shallow braided river delta in the upper Huagang Formation in the central-northern part of Xihu Sag,East China Sea Basin

作　　者：陈春峰 徐东浩 张银国[2] 唐贤君 万延周 冯桢鸣 何新建 俞伟哲 CHEN Chunfeng;XU Donghao;ZHANG Yinguo;TANG Xianjun;WAN Yanzhou;FENG Zhenming;HE Xinjian;YU Weizhe(Shanghai Branch of CNOOC(China)Ltd.,Shanghai 200335,China;Qingdao Institute of Marine Geology,China Geological Survey,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：《海洋地质前沿》2024年第10期39-48,共10页Marine Geology Frontiers

基　　金：中海石油(中国)有限公司综合科技项目“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”(KJZH-2023-2103)。

摘　　要：从分析岩芯资料和砂体平面展布着手,重新厘定了东海盆地西湖凹陷中北部花港组上段H4、H5砂组的沉积相,创新提出了研究区花上段发育浅水辫状河三角洲沉积,研究区中南部发育规模性砂体。研究认为:在研究区的西部及东部边缘为辫状河三角洲平原相主导区,以发育辫状河三角洲平原河道砂体为主,局部有少量的辫状河三角洲前缘相发育。在研究区的中部及中南部,为辫状河三角洲平原与辫状河三角洲前缘交互发育区,主要特征是在较短的沉积期内形成了三角洲平原相与三角洲前缘相交互沉积;在枯水期时,以发育三角洲平原沉积为主,南部边缘发育三角洲前缘相沉积;在丰水期时,主要发育三角洲前缘相沉积及少量浅湖相沉积。在浅水辫状河三角洲沉积模式指导下,在研究区中南部发现了众多三角洲水道砂体及朵叶状砂体,这些砂体被钻井证实为油气藏。研究区的中南部仍然是油气勘探的潜力区,这一认识已被最新探井所证实。The sedimentary facies of H4 and H5 sand groups of the upper part of Huagang Formation in the central and northern Xihu Sag of the East China Sea Basin were redefined based on the analysis of core data and sand body distribution.New understanding is obtained that shallow water braided river delta was developed in the study area,showing large-scale sand bodies formed in the central and southern parts of the study area.Results suggest that:The western and eastern flanks of the study area are dominated by braided river delta plain facies,with a small area that dominated by braided river delta front facies.In the central and central-southern parts of the study area,the braided river delta plain and delta front were developed,which is mainly characterized by the inter-layer sediments of delta plain and delta front in a short interval.In the dry season,delta plain sediments developed in most of the area,and delta front sediments developed in the southern margin.In the flooding season,delta front sediments and a small amount of shallow lake sediments were developed.Under the guidance of the shallow braided river delta sedimentary model,a number of delta channel sand bodies and mouth bar sand bodies were recognized.This area is potential for oil and gas exploration,which has been confirmed by the latest exploration wells.

关 键 词：东海盆地 西湖凹陷 浅水辫状河三角洲沉积 花港组 砂体展布 

分 类 号：P618.13[天文地球—矿床学]