Sub-seismic deformation on different scales in the North German Basin

沉积盆地的演化特别受变形的影响。大规模的地下变形通常通过地震数据的解释来识别，并通过地震重建来评估。然而，这些研究也表明，次地震的小规模的裂缝发挥了重要作用：它们可能容纳在盆地演化过程中的总应变的显着比例（高达50%），侧向变化可能会导致分隔的存款和水库，和裂缝网络可能会作为管道成岩流体。在Northgerman盆地，这些实际上未知的方面需要用不同的方法分析断裂系统的位置、方向和长度分布，以确定a）变形的大小，B）空间和时间上的应变积累，以及c）在不同的运动学约束下盆地演化期间控制a）和B）的过程。为了解决这些问题，我们的研究旨在1）通过地震解释和3D逆变形来量化和预测NGB中高应变或低应变积累的区域，2）通过裂缝系统的分形分析和钻孔和样品数据的校准来验证这些预测，和3）将观察到的和预测的应变模式与缩放模拟实验的应变模式进行比较，以解开不同尺度长度下的关系代表NGB中单位的结构。为此，我们选择了Völkersen地区，在那里可以获得石油工业的适当油井和三维地震数据。

The evolution of a sedimentary basin is most particularly affected by deformation. Largescale, subsurface deformation is typically identified by the interpretation of seismic data and evaluated by palinspastic reconstruction. These studies also show, however, that sub-seismic small-scale fractures play a significant role: they may accomodate a significant proportion of the total strain (up to 50%) during basin evolution, laterial variation may cause compartmentalised deposits and reservoirs, and fracture networks may act as conduits for diagenetic fluids. In the Northgerman Basin these virtually unknown aspects require an analysis of location, orientation and length distribution of the fracture systems with different methods for determining a) the magnitude of deformation, b) the strain accumulation in space and time, and c) the processes that control a) and b) during basin evolution under varying kinematic constraints. To address these topics, our study aims to 1) quantify and predict areas of high- or low-strain accumulation in the NGB with seismic interpretation and 3D retro-deformation, 2) validate these predictions with fractal analysis of fracture systems and calibration with drill hole and sample data, and 3) compare observed and predicted strain patterns with those from scaled analogue experiments to unravel the relationship at different scale lengths within structures representative of units in the NGB. For this purpose we have chosen the Völkersen area where both appropriate well and 3D seismic data from oil industry are available.