High-Resolution Genetic Interpretation of Salt Structure Geometries and Their Near-Diapir Sedimentation
Mohr, Markus1,
Peter A. Kukla1, Janos L. Urai1,
Georg Bresser2 (1) RWTH Aachen University, Aachen,
Germany (2) Gaz de France Production Exploration
Germany GmbH, Lingen (Ems),
High quality seismic data enable us to present complex outlines
of salt structures related to hydrocarbon systems of the North German basin.
Our high-resolution genetic interpretation of salt structure geometries and
their associated sedimentation improves exploration in the subsalt
and at the diapir flanks.
We combine 3D and 2D seismic interpretation of pre-stack depth
migrated data with 2D & 3D kinematic and
geometrical backward
modelling. Retro-deformed models
for specific time slices characterize the evolution of the salt terrane. This allows us to identify salt movement at
certain times, to assign possible regional tectonic trigger mechanisms and to
uncover the relevant salt tectonic processes. We achieved a better resolution
of the sedimentary patterns and processes affected by salt movement with
additional well-log analysis and compared the results to the regional
sedimentary and stratigraphic framework.
We interpreted several salt wedges formed by lateral extrusions
during periods with emerged diapirs and reduced
sediment accumulation. Paleo-cap rock blocks
identified inside the diapirs give evidence of long
phases of dissolution. An increased sediment-sup-ply resulted in the onlapping of strata onto the diapir.
These halokinetic sequences recorded the
salt-sediment interaction of predominantly non-marine layers and bear a number
of potential hydrocarbon traps.
Our better
understanding of the structural, sedimentary and salt tectonic evolution and
our improved knowledge of the position and amount of salt has effects on
seismic modelling and depth conversion and improves
the prediction of potential Upper Permian gas reservoirs in the sub-salt
sequences.