南海白云凹陷渐新统珠海组沉积相及其演化  

Sedimentary facies and evolution of Oligocene Zhuhai Formation in Baiyun Sag,South China Sea

作　　者：田兵[1] 郑有伟 赵俊梅[1] TIAN Bing;ZHENG Youwei;ZHAO Junmei(Inner Mongolia University of Science and Technology,Baotou 014010,China)

机构地区：[1]内蒙古科技大学,内蒙古包头014010

出　　处：《断块油气田》2022年第6期800-806,836,共8页Fault-Block Oil & Gas Field

基　　金：国家科技重大专项课题“南海北部深水区关键成藏期优质储层形成机理及预测技术”(2016ZX05026-007)。

摘　　要：渐新统珠海组为南海北部深水区重要的油气勘探目的层段。综合应用岩心、测井、地震等资料,详细分析了白云凹陷珠海组的层序特征、沉积相类型及分布特征,明确了其沉积演化过程。研究结果表明:白云凹陷珠海组自下而上可划分为SQ1-1,SQ1-2,SQ1-3等3个三级层序,主要发育陆架三角洲、陆架边缘三角洲、深水扇、扇三角洲与海相沉积。珠海组SQ1-1沉积时期,近源陆架三角洲在白云凹陷北缘广泛分布,海相主要分布在凹陷南侧,扇三角洲发育在凹陷西南控洼断层之下;SQ1-2,SQ1-3沉积时期,在古珠江充足物源、区域构造沉降及海平面变化控制下,凹陷内形成北西—南东向大型陆架三角洲-陆架边缘三角洲-深水扇沉积体系组合,西南侧扇三角洲体系持续发育,规模逐渐缩小。The Oligocene Zhuhai Formation is an important target interval for oil and gas exploration in the northern deep-water area of the South China Sea.Using core,logging and seismic data,the sequence characteristics,sedimentary facies types and distribution characteristics of Zhuhai Formation in Baiyun Sag were analyzed in detail,and the sedimentary evolution process was clarified.The results show that the Zhuhai Formation in Baiyun Sag can be divided into three third-order sequences such as SQ1-1,SQ1-2 and SQ1-3 from bottom to top,in which the main sedimentary facies of shelf delta,shelf-margin delta,deep-water fan and marine sediment are developed.During the sedimentation of SQ1-1,the shelf delta of near source was widely distributed in the northern margin of Baiyun Sag,the marine facies were mainly distributed in the south side of the sag,and the fan delta was developed under the southwest controlled fault of the sag.During the sedimentation of SQ1-2 and SQ1-3,under the control of sufficient provenance of Paleo-pearl River,regional tectonic subsidence and sea level change,the NW-SE trending sedimentary system combination of large shelf delta,shelf margin delta and deep water fan was formed in the sag.The fan delta system in the southwest was developed continuously and its scale decreased gradually.

关 键 词：沉积相 沉积演化 珠海组 渐新统 白云凹陷 

分 类 号：TE121.3[石油与天然气工程—油气勘探]