南海白云凹陷深水区渐新世—中新世断阶陆架坡折沉积过程响应

Sedimentary Responses of Retreating Shelf Break from Oligocene to Miocene,in Deep Water Area of Baiyun Depression,South China Sea

南海珠江口盆地白云凹陷深水区在渐新世—中新世经历了后退断阶式的陆架坡折带演化,该过程控制了本地区沉积体系的发育和分布,从而也在一定程度上影响了油气藏的形成与分布。基于近期最新钻井资料、精细沉积学分析和长电缆高质量三维地震资料解释,结合陆架边缘三角洲沉积模式理论,开展了该区断阶陆架坡折控制的沉积过程响应特征研究。发现渐新世陆架坡折带主要的沉积过程响应是珠海组陆架边缘三角洲前积楔-浅海陆架沉积体系,中新世后退断阶陆架坡折主要沉积响应为生长断层复杂化的陆架边缘三角洲与斜坡扇体系,该发现将有助于指导深水油气勘探。

Retreating Shelf Break occurred from Oligocene to Miocene in deep water area of Baiyun depression,South China Sea,which controlled the development and distribution of sedimentation in the study area.And,to some extent,effective reserves are formed.Based on the latest drilling data,detailed sedimentary analysis and meticulous interpretation of long cable,high quality,three dimensional seismic data,research of sedimentary responses of retreating shelf break is carried out,meanwhile integrating the theories of shelf-margin delta,which indicates that the responses of shelf break is shelf-margin delta progradational system of Zhuhai Formation in Oligocene and growth faults complicating shelf-margin delta and deep-water fan system of Zhujiang Formation.This discovery will be favorable for oil and gas exploration of Baiyun Depression.