下刚果盆地晚渐新世—中新世挤压带盐构造地貌特征及其对重力流沉积的控制作用  

Geomorphology characteristics of salt structures and their controlling effects of gravity flow deposits in the contraction belt from Late Oligocene to Miocene in the Lower Congo Basin

作　　者：郭荣涛 林东升[1] 张忠民[1] 宫越 杨誉 汪锴 刘静静[1] 王兴华[1] GUO Rongtao;LIN Dongsheng;ZHANG Zhongmin;GONG Yue;YANG Yu;WANG Kai;LIU Jingjing;WANG Xinghua(Petroleum Exploration and Production Research Institute,SINOPEC,Beijing 100083,China;School of Ocean Sciences,China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]中国石化石油勘探开发研究院,北京100083 [2]中国地质大学(北京)海洋学院,北京100083

出　　处：《东北石油大学学报》2025年第1期18-32,90,I0002,I0003,共18页Journal of Northeast Petroleum University

基　　金：国家科技重大专项(2016ZX05033);中国石化科技部项目(P21043-4)。

摘　　要：下刚果盆地挤压带盐构造样式复杂,制约深水有利储集砂体的发育分布。根据高精度三维地震、二维格架剖面和钻测井、岩心等资料,分析下刚果盆地晚渐新世—中新世被动陆缘层序格架、盐构造地貌特征及其对重力流沉积物分散体系的控制作用。结果表明:下刚果盆地上渐新统—上新统可划分5个三级层序(SS5-1—SS5-5),各三级层序进一步划分为低位体系域—水进体系域和高位体系域;盐底辟构造分为点状供源和线状供源,点状供源的盐底辟构造包括盐株、盐席和盐席篷,平面上呈不规则的圆形或椭圆形,线状供源的盐底辟构造包括盐滚、盐背斜、盐墙和盐墙篷,平面上呈条带状;盐构造发育4期演化阶段,即初始流动期、变形期、强烈变形期和稳定变形期;不同区带盐构造样式形成的地貌及其演化对沉积物分散和充填具有控制作用,盐构造导致的“坝—池”地貌控制区域性的沉积物通道分布和扇体系发育;渐新世—中新世各层序沉积期,下刚果盆地地貌总体呈东高西低的特点,各级坡折和盐构造主要呈北西—南东向展布,形成切割大陆斜坡的“纵沟”与北北西向的盐构造限制的“横槽”地貌,制约重力流体系沉积物分散和微盆地沉积充填。该结果对下刚果盆地挤压带浊积砂岩油气勘探具有指导意义。The salt structure style of the compressed structural zone in the Lower Congo Basin is complex,which restricts the development and distribution of deep-water favorable reservoir sand bodies.Based on high precision 3D seismic data,2D lattice profile,drilling and logging data,core data,the Late Oligocene-Miocene passive continental margin sequence framework,salt structure geomorphology features and their controlling effects on gravity flow dispersal system in the Lower Congo Basin are systematically studied.The results indicate that the Upper Oligocene-Pliocene in the Lower Congo Basin can be divided into five third-order sequences(from SS5-1 to SS5-5),which are further divided into the low system tracks and high system tracks.The salt diapir structure can be divided into point shaped and linear shaped sources.The point shaped sources include salt plants,salt mats and salt canopies,which are irregularly circular or elliptical in plan.The linear shaped sources include salt rolls,salt anticlines and salt walls,which are strip-shaped in plan.The development of salt structures involves four stages of evolution,namely the initial flow stage,deformation stage,strong deformation stage,and stable deformation stage.The landforms and their evolution formed by different salt structure styles in different zones have a controlling effect on the dispersion and filling of sedimentary deposits during the sedimentary period,and the“dam-pool”landform caused by salt structure controls the distribution of regional sediment channels and the development of fan system.During the sedimentary periods of each sequence from the Oligocene to the Miocene,the geomorphology of the Lower Congo Basin is generally high in the east and low in the west.The slope breaks and salt structures are mainly spread in a northwest-southeast direction,forming a“longitudinal trench”that cuts the continental slope and a“transverse trough”that is restricted by the salt structure in a NNW direction,which restricts the sediment dispersal of gravity flow

关 键 词：盐构造地貌 重力流沉积 沉积物分散 控制作用 挤压带 下刚果盆地 

分 类 号：TE121.1[石油与天然气工程—油气勘探]