穆尼盆地第四纪深水弯曲水道:沉积构型、成因及沉积过程

深水水道是陆坡沉积的重要组成单元,深水水道储层受到广泛关注。基于高分辨率三维地震资料,利用地震属性、分频技术等研究穆尼盆地第四纪深水弯曲水道的沉积构型、成因及沉积过程,主要取得以下3个方面的成果:(1)建立了深水弯曲水道沉积构型模式。弯曲深水水道由水道和堤岸组成。堤岸脊将堤岸分成内堤岸和外堤岸两部分。水道由底部粗粒滞留沉积、深海泥质披覆沉积以及滑块组成。(2)深水水道早期为低弯曲水道,后期逐渐演化为高弯曲水道。(3)建立了深水弯曲水道沉积的岩相模式,深水弯曲水道由垂向加积水道和侧向迁移水道组成。顺重力流方向,侧向迁移带,内弯带以沉积作用为主,外弯带以侵蚀作用为主。垂向加积带,水道底部粗粒滞留沉积往往表现为垂向加积特征。深水弯曲水道岩相模式的建立对深水浊积水道储层准确预测具有重要的理论指导意义。

Quaternary Sinuous Submarine Channel in Muni Basin:Architecture, Genesis and Process

Submarine channels are important components of continental slope.Great attentions are attached to deep-water channel reservoirs.Based on the high resolution 3-D seismic data,seismic attribute and SpecDecomp are used to study the architecture,genesis and process of the Quaternary submarine channels in Muni basin.There are three main conclusions:(1)Model of sedimentary architecture in sinuous submarine channels are built in this paper.Submarine channels are composed of channel and levee.Channels can be divided into two parts by levee crest: inner levee and outer levee.Channel fills are consisted of the coarse lag,hemipelagic mud drape deposits and slide.(2)The evolution process of submarine channel has been summaried.In the early stage,submarine channel is characterized by low sinuous channel,and in the later stage,by high sinuousity.(3)Lithofacies models of sinuous submarine channel are established in this paper.Sinuous submarine channels are composed of migration channel and aggradation channel.Along gravity-flow channel,the inner concave is mainly sedimentation while the outer gives priority to erosion process.Coarse channel-lag deposits are characterized by aggradation.Lithofacies model of sinuous submarine channel is an important theoretical significant for accurate reservoir prediction of deepwater turbidity.