Interpretation of a 3D seismic survey located on the western margin of the Northern North Sea Basin demonstrates how the propagation, overlap and linkage of two north–south-striking, en echelon normal fault segments exerted a powerful influence over prospective subtle stratigraphic traps. The relay ramp that formed between the segments appears to have focused sediment dispersal, controlled reservoir distribution and aided post-depositional petroleum migration. Integration of electrical well log data, root-mean-square (RMS)-amplitude analysis and biostratigraphy with seismic interpretation demonstrates that a series of elongate, linear, sand-prone (reservoir) channel complexes characterize the depositional slopes generated by fault growth. The combination of synsedimentary rotation of bedding due to fault propagation and associated footwall uplift led to erosion and truncation of a laterally extensive, older channelized system (Lower Sequence), the downdip parts of which extend beyond the relay ramp. Its subsequent drape by transgressive shales created the subtle stratigraphic trap that now hosts the Cladhan Field, with charge occurring because the sandstones belonging to the Lower Sequence extend as far as the active kitchen in the neighbouring (hanging-wall) depocentre situated downdip and to the east. In contrast, the exploration of a younger, Upper Sequence of sandstones has proven to be disappointing due to their more restricted distribution, lack of access to charge, and occurrence of faults that offset and breach the thin end of the stratigraphic wedge. The implication is that partially breached relay ramps not only provide a preferential site for syn-rift clastic reservoirs to develop but also form important migration pathways through which oil passed from a petroleum kitchen into a trap. Thematic collection: This article is part of the Under-explored plays and frontier basins of the UK continental shelf collection available at: http://www.lyellcollection.org/cc/under-explored-plays-and-frontier-basins-of-the-uk-continental-shelf

中文翻译：

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接力坡道演化在控制北海北部同裂谷地层沉积物扩散和油气远景中的作用

对位于北海盆地北部西缘的 3D 地震勘探的解释表明，两个南北走向的梯形正断层段的传播、重叠和联系如何对潜在的微妙地层圈闭产生强大的影响。分段之间形成的中继坡道似乎集中了沉积物的扩散，控制了储层分布，并有助于沉积后的石油运移。电测井数据、均方根 (RMS) 振幅分析和生物地层学与地震解释的整合表明，一系列细长、线性、易出砂（储层）的通道复合体表征了断层生长产生的沉积斜坡。由于断层传播和相关的下盘抬升，层理的同沉积旋转相结合，导致了横向广泛的、较旧的渠道系统（下层序）的侵蚀和截断，其下倾部分超出了中继斜坡。它随后被海侵页岩覆盖形成了现在拥有 Cladhan 油田的微妙地层圈闭，由于属于下层序的砂岩一直延伸到位于下倾的相邻（悬壁）沉积中心的活动厨房和东方的。相比之下，对较年轻的上层序砂岩的勘探已被证明是令人失望的，因为它们的分布更受限制，无法获得电荷，并且出现了抵消和破坏地层楔薄端的断层。这意味着部分破裂的中继坡道不仅为同裂隙碎屑岩储层的发育提供了优先位置，而且还形成了重要的运移通道，石油通过该通道从石油厨房进入圈闭。专题收藏：本文是英国大陆架收藏的未开发区和边境盆地的一部分，可在以下网址获取：http://www.lyellcollection.org/cc/under-explored-plays-and-frontier-basins-of -英国大陆架