东海西湖凹陷孔雀亭地区始新统平湖组中段沉积特征  

Sedimentary characteristics of the middle member Pinghu Formation of Eocene in Kongqueting area,Xihu Sag,East China Sea Shelf Basin

作　　者：陈生华 王健伟[2] 刘舒 严曙梅[2] 韩建辉[1] 傅恒[1] 谢才铸 孙莉[2] CHEN Shenghua;WANG Jianwei;LIU Shu;YAN Shumei;HAN Jianhui;FU Heng;XIE Caizhu;SUN Li(College of Energy,Chengdu University of Technology,Sichuan,Chengdu,610059,China;Exploration and Development Research Institute of Sinopec Shanghai Ocean Oil&Gas Breach,Shanghai,200120,China)

机构地区：[1]成都理工大学能源学院,成都610059 [2]中国石化上海海洋油气分公司勘探开发研究院,上海200120

出　　处：《岩性油气藏》2025年第2期103-114,共12页Lithologic Reservoirs

基　　金：中国石化上海海洋油气分公司科研项目“孔雀亭气田始新统宝石组—平湖组沉积微相及有利区分布研究”(编号:34000002-22-ZC0613-0008)资助。

摘　　要：根据钻井岩心、测井、高精度三维地震等资料,利用古地貌恢复、地震相识别、数学逐步回归模型融合属性等方法,对东海陆架盆地西湖凹陷始新统平湖组中段沉积体系及砂体展布特征进行详细研究。研究结果表明:①西湖凹陷孔雀亭地区平湖组可识别出1个二级层序,5个三级层序,古地貌呈北西—南东向阶梯式加深格局,沉积物源来自西北部的海礁凸起;②研究区平湖组中段位于三级层序的高位体系域,主要发育辫状河三角洲—有障壁滨海沉积体系,可细分为三角洲平原、三角洲前缘、前三角洲及潮坪4个亚相;③研究区砂体主要发育于三角洲平原分流河道、三角洲前缘水下分流河道及河口坝3个微相中,平湖组中段主要发育P8,P7,P6共3个砂层组,对应于平湖组中段高位体系域内的3个四级旋回,从最大海泛面开始发育P8砂层组,高位体系域中期发育P7砂层组,高位体系域末期发育P6砂层组。The middle member Pinghu Formation in the Eocene strata on the western slope of the Xihu Sag within the East China Sea Shelf Basin,specifically within the Kongqueting Block,is the primary oil and gas reservoir.However,systematic studies of the detailed sedimentary evolution and sand body distribution within the third-order sequence framework in this block remain lacking,limiting the effectiveness of oilfield development.By integrating lithology,well logs,and high-resolution 3D seismic data,the sedimentary system and sand body distribution of middle member Pinghu Formation in the Eocene strata on the western slope of the Xihu Sag within the East China Sea Shelf Basin were characterized using methods such as paleo-geomorphology restoration,seismic facies identification,and attribute integration through a stepwise regression model.The results show that:(1)In terms of sequence stratigraphy,a secondary sequence and five tertiary sequences can be identified within the Pinghu Formation.The ancient topography within this sequence framework was characterized by a northwestsoutheast gradient of stepped deepening,and sediments in the study area were derived from the northwestern continental margin uplift.(2)The middle member Pinghu Formation is located in the highstand systems tract(HST)of a third-order sequence,primarily developing a braided river delta-barrier coastal depositional system.This system can be further subdivided into four sub-facies—delta plain,delta front,prodelta,and tidal flat.(3)The macroscopic boundaries of sand body distribution,showing that sand bodies primarily develop within three microfacies:delta plain distributary channels,delta front subaqueous distributary channels,and mouth bars.The middle member Pinghu Formation primarily develops three sand layers,P8,P7,and P6,corresponding to three fourth-order cycles within the highstand systems tract(SQE2p3)of the middle Pinghu section.The development sequence begins with P8 at the maximum flooding surface,followed by P7 in the mid-highstand phase,and th

关 键 词：层序地层 分流河道 水下分流河道 河口坝 地震属性 平湖组 始新统 孔雀亭地区 西湖凹陷 东海陆架盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]