Kinematic 3D Retro-Deformation of Fault Blocks Picked from 3D Seismics; Correlation of Strain Results with Natural Data
Abstract
Deformation of fault-near strata is not primarily dependent on the displacement along the fault, but rather on the variation in the morphology of the fault plane (in the direction of fault movement) and on the rate of change in fault-plane parallel displacement. Much of this deformation is below the resolution of reflection seismics (i.e. sub-seismic). Kinematic 3D restoration offers a method to define the magnitude and extent of sub-seismic fault damage, which is extracted from the strain tensor for each point in the model. We show examples of Permian Rotliegend faults picked from a 10×15 km2 3D reflection seismic block from the North German Basin. The Rotliegend aeolian and fluviatile sandstones form an onshore gas play, which lies at a depth of greater than 4500 m. Evaluation of the surfaces of major Rotliegend faults, using their Gaussian curvature and cylindricity, suggests these are normal faults with dominantly `dip-slip' movement. We demonstrate the retro-deformation of these faults, and show the strain tensor values and orientations which occurred in the surrounding strata. We propose the values of the strain tensor, and thus the magnitude of the strain, are equivalent after retro- or forward deformation, and consequently we are able to compare the modelling results with natural data, such as fracture data from boreholes.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2005
- Bibcode:
- 2005AGUFM.S41B0978T
- Keywords:
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- 5104 Fracture and flow;
- 7209 Earthquake dynamics (1242);
- 7215 Earthquake source observations (1240);
- 8004 Dynamics and mechanics of faulting (8118);
- 8034 Rheology and friction of fault zones (8163)