HR: 1340h
AN: T33C-1493    [Abstracts]
TI: Sub-/Seismic Structure and Deformation Prediction across different scales between 1D well data and 3D reflection seismics
AU: * Krawczyk, C M
EM: lotte@gga-hannover.de
AF: Leibniz Institute for Applied Geosciences (GGA), Stilleweg 2, Hannover, D-30655, Germany
AU: Lohr, T
EM: lohr@gfz-potsdam.de
AF: GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, D-14473, Germany
AU: Tanner, D C
EM: dtanner@gwdg.de
AF: GZG Goettingen, Goldschmidtstrasse 3, Goettingen, D-37077, Germany
AU: Oncken, O
EM: oncken@gfz-potsdam.de
AF: GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, D-14473, Germany
AB: The evolution of a sedimentary basin is mostly affected by deformation. Large-scale, subsurface deformation is typically identified by seismic data, small-scale fractures by well data. However, faulting at the medium sub- seismic scale plays an important role, e.g. in reservoirs: large individual reservoirs can be disrupted by faults enhancing fluid flow, or producing compartmentalized deposits due to cementation of fractures. Thus, between both scales, seismic and well data, we lack a deeper understanding of how deformation scales in the sub- seismic region. To start tackling this problem, a 3D reflection seismic data set in the North German Basin was analysed with respect to structure and faults in great detail, calibrated by well data. This led to the determination of magnitude and distribution of deformation and its accumulation in space and time on the seismic scale. The structural interpretation unravels the kinematics in the North German Basin with extensional events during basin initiation and later inversion. For further quantitative deformation and fracture prediction on the sub-seismic scale, two different approaches are introduced. An increased resolution of subtle tectonic lineaments is achieved by coherency processing yielding together with geostatistic tools the distribution of low- and high-strain zones in the region. Independently, the distribution and quantification of the strain magnitude is predicted from geometrical 3D retro-deformation of the identified structures. For the fault structure analysed, it shows major-strain magnitudes between 5-15% up to 1.5 km away from a fault trace, and variable deviations orientation of associated extensional fractures. The small scale is represented by FMI data from borehole measurements, showing main fault directions and densities. These well data allow the validation of our sub-seismic deformation analyses. In summary, the good correlation of results across the different scales makes the prediction of small- scale faults/fractures possible. The temporal component of faulting will be gained in the future by analogue models. The suggested geomechanical workflow is applicable to reflection seismic data, but requires the 3D coverage of a region as basic principle. It yields in great detail both the tectonic history of a region as well as predictions for the genesis of structures below the resolution of reflection seismics.
DE: 8010 Fractures and faults
DE: 8011 Kinematics of crustal and mantle deformation
DE: 8012 High strain deformation zones
DE: 8020 Mechanics, theory, and modeling
DE: 8169 Sedimentary basin processes
SC: Tectonophysics [T]
MN: 2007 Fall Meeting