白云凹陷北坡珠江组下部储层生物遗迹及沉积演化特征  

Characteristics of sedimentary reservoirs trace fossils and sedimentary evolution in the lower Zhujiang Formation on north slope of Baiyun Sag

作　　者：吴伟[1] 白晓婧 刘惟庆[1] 刘俊成[2] 邢智峰[1] 周永 王光绪 冯阵东 WU Wei;BAI Xiaojing;LIU Weiqing;LIU Juncheng;XING Zhifeng;ZHOU Yong;WANG Guangxu;FENG Zhendong(School of Resources and Environment in Henan Polytechnic University,Jiaozuo 454000,China;Jiangsu Oilfield No.2 Oil Production Plant,SINOPEC,Yangzhou 225000,China)

机构地区：[1]河南理工大学资源环境学院,河南焦作454000 [2]中国石化江苏油田采油二厂,江苏扬州225000

出　　处：《中国石油大学学报（自然科学版）》2023年第1期12-24,共13页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家自然科学基金项目(41872112,42077410)。

摘　　要：南海北部珠江口盆地的白云凹陷北坡新近系底部的陆架边缘三角洲前缘砂体有良好的油气储集条件,具有巨大的油气勘探价值。以珠江口盆地白云凹陷北坡—番禺低隆起珠江组下部为研究对象,将常规的岩心观察、地震相分析等手段与生物遗迹分析相结合,探索其沉积环境特征及演化规律。结果表明:陆架坡折处发育陆架边缘三角洲前缘亚相沉积,发育以水下分流河道和河口坝为主的沉积微相,发育Skolithos遗迹相,局部生物扰动剧烈。陆架坡折以北整体发育滨海三角洲沉积,以分流间湾和水下分流河道沉积微相为主,发育Skolithos-Cruziana遗迹相,生物扰动程度以中等—剧烈扰动为主,局部为稀少生物扰动。研究区的沉积演化可以分为海退期(21.0~19.0 Ma)和海侵期(19.0~18.5 Ma)两个阶段,海退期物源充沛,在陆架坡折处发育陆架边缘三角洲前缘亚相沉积;海侵期海平面上升,发育退积三角洲,在陆架坡折以北发育滨海三角洲前缘亚相沉积。The delta front sand body of the continental shelf edge at the bottom of Neogene, which is located on the north slope of Baiyun Sag in Pearl River Mouth Basin in the northern South China Sea, has good oil and gas reservoir conditions and great oil and gas exploration value. Taking the north slope of Baiyun Sag in the Pearl River Mouth Basin—the lower part of Zhujiang Formation in Panyu Low Uplift as the research object, this paper combines conventional core observation, seismic facies analysis and biological relic analysis to explore its sedimentary environment characteristics and evolution law. It is found that shelf margin delta front subfacies, sedimentary microfacies are dominated by underwater distributary channel and estuarine bar;and skolithos relic facies and severe local biological disturbance are developed at the shelf slope break. To the north of the shelf slope break, coastal delta deposits are developed as a whole, which are dominated by distributary bay and underwater distributary channel sedimentary microfacies, Skolithos cruziana relic facies are developed. The degree of biological disturbance is mainly medium severe disturbance, and locally is rare biological disturbance. The sedimentary evolution of the study area can be divided into two stages: the regression period(21.0-19.0 Ma) and the transgression period(19.0-18.5 Ma). The material source was abundant in the regression period, and the shelf margin delta front subfacies were developed at the shelf slope break. During the transgressive period, the sea level rose and the retrograde delta was developed, and the coastal delta front subfacies were developed to the north of the shelf slope break.

关 键 词：陆架边缘三角洲 滨海三角洲 沉积相 生物遗迹 沉积演化 白云凹陷 

分 类 号：TE121.3[石油与天然气工程—油气勘探]