新西兰深水Taranaki盆地中新统深水水道迁移及沉积演化

深水水道砂体是深海油气的重要储集体之一,其复杂的演化规律常常影响水道砂体储层的分布,无法充分了解深水水道的演化过程是阻碍深海油气勘探开发的原因之一,增大了深海油气的勘探开发难度。以新西兰深水Taranaki盆地中新统深水水道为例,基于高分辨率三维地震数据,应用地震地貌学、地震沉积学的理论及技术手段,探究水道的沉积演化规律及相关控制因素。研究区水道体系可划分为5个发育期次,即残余部分结构的复合水道Ⅰ、侧向迁移的复合水道Ⅱ、垂向叠置的复合水道Ⅲ、富泥充填的复合水道Ⅳ及零散分布的复合水道Ⅴ。复合水道Ⅰ和Ⅳ呈相对顺直的平面形态;复合水道Ⅱ多为侧向迁移运动,表现为高弯曲的平面形态,而复合水道Ⅲ多为垂向叠置运动,其弯曲度较复合水道Ⅱ有所减小;复合水道Ⅴ包括多条零散的细小单水道,不同单水道的平面形态存在较大差异。各期次复合水道的演化过程可归纳为初期下切侵蚀、中期充填沉积及末期填平消亡等3个阶段。深水水道沉积演化过程受多种因素综合控制,早期水道结构会影响后期水道发育环境的限制程度,强限制性的复合水道Ⅰ～Ⅳ经历有序的演化过程,非限制性的复合水道Ⅴ则经历了无序的演化过程;重力流规模及能量的变化会影响各期次...

Migration and Sedimentary Evolution of the Miocene Deep-water Channel in the Deep-water Taranaki Basin,New Zealand

A deep-water channel body is one of the principal reservoirs of deep-sea petroleum. The complex evolution of a deep-water channel affects the distribution of the channel sand reservoir, thus increasing the difficulty of deep-sea petroleum exploration and development. Taking the Miocene channel system in the deep-water Taranaki Basin of New Zealand as an example, based on high-resolution three-dimensional （3D） seismic data, the sedimentary evolution rules and controls of the channel were explored by using the theories and technical means of seismic geomorphology and sedimentology. The development of the channel system can be divided into five stages: composite channel I with the residual structure, composite channel Ⅱ with horizontal migration and swing, composite channel Ⅲ with vertical and overlapping migration, composite channel Ⅳ with muddy and disorderly filling, and scattered composite channel V. Composite channels I and Ⅳ were relatively straight in plane morphology. Composite channel Ⅱ primarily exhibits lateral migration movement, showing a high sinuous plane morphology. Composite channel Ⅲ depicts vertical overlapping movement, and its bending is reduced compared with composite channel Ⅱ. Composite channel V includes several scattered small single channels, with great differences in their plane morphology. Each stage of channel evolution can be divided into initial-stage downcutting erosion, medium-stage filling deposition, and terminal-stage filling extinction. The sedimentary evolution process of the deep-water channel is comprehensively controlled by many factors. The early channel structure affects the restriction degree of later channel development environment. The evolution of composite channels I-IV in a strong restrictive environment is orderly, while the evolution of composite channel V in a non-restrictive environment is disordered. The change of gravity flow scale and energy affects the scale of each composite channel. The inability to fully understand the evolution process of the channel is one of the reasons hindering deep-sea petroleum exploration and development. This study explores the evolution of the channel to provide reference for deep-sea petroleum exploration and development.