被动陆缘深水海底限制性水道三维地震表征及沉积演化——以纳米贝盆地为例  

Seismic Response and Sedimentary Evolution of a Deepwater Channel at a Passive Continental Margin:Case study of the Namibe Basin

作　　者：付志方 宫越 苏玉山[1] 郭荣涛 林东升 汲生珍 FU ZhiFang;GONG Yue;SU YuShan;GUO RongTao;LIN DongSheng;JI ShengZhen(Exploration and Production Research Institute,SINOPEC,Beijing 100083,China)

机构地区：[1]中国石油化工股份有限公司石油勘探开发研究院,北京100083

出　　处：《沉积学报》2024年第1期228-237,共10页Acta Sedimentologica Sinica

基　　金：国家科技重大专项(2016ZX05033002-002);中石化科技攻关项目(P21043-2)。

摘　　要：【目的】被动陆缘盆地深水浊积砂体已成为深海油气勘探突破及储量发现的新领域。【方法】以典型被动陆缘纳米贝盆地深水高分辨率三维地震资料为研究基础,以受构造活动和沉积压实影响较小而保持原始水道沉积构型的海底第四纪沉积地层为目标,精细描述和解析了目标层内限制性水道沉积的剖面和平面地震响应特征。【结果与结论】限制性浊积水道侵蚀作用总体大于沉积作用,单一水道的沉积模式以凹岸侵蚀、凸岸“S”型加积为主,该过程使“V”型河谷展宽并充填形成“U”型水道沉积;多期叠置水道沉积体系分为侧切叠置和垂切叠置的两种模式,以侧切叠置模式为主;窄陆架、宽缓陆坡的海底地形控制限制性水道的延伸方向及长度规模,陆缘盆地的沉降中心控制着各期水道的迁移方向,古气候事件发生频率控制着水道体系内部浊积砂体发育的期次。该研究成果能够给予限制性水道沉积构型认识及砂体储层预测启发。[Objective]Deepwater turbidite sand bodies in passive continental margin basins are a new field of oil and gas exploration.[Methods]High-resolution 3D seismic data for a typical passive deepwater basin margin(in this case,the Namibe Basin margin)enabled the sedimentary characteristics of limited channel submarine Quaternary sedimentary strata to be finely depicted and analyzed.Because these have been relatively unaffected by tectonic activ-ity and sedimentary compaction,they have retained the original sedimentary configuration of the channel.[Results and Conclusions]It was found that the erosion of confined turbid channels generally exceeded deposition.The sedi-mentary mode of a single channel exhibits mainly concave bank erosion and convex bank‘S’-type accretion,leading to‘V’-type valley broadening into wide‘U’-type channel deposition.Multiple-channel sedimentary systems are di-vided into either lateral or vertical erosive superposition.The submarine topography of a narrow continental shelf and a wide,gentle continental slope has determined both the direction and length of extension of limited channels.The frequency of paleoclimate events has affected the developmental times of turbidite sand bodies in the channel system.These results provide information for predicting the presence of reservoirs and for analyzing the sedimentary architec-ture of channel turbidite sand bodies in exploration for oil and gas in this type of deep formation.

关 键 词：被动陆缘 深水限制性水道 地震表征 沉积模式 控制因素 

分 类 号：P618.13[天文地球—矿床学]