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Mapping, Modeling and Evolution of 
Salt
Structure Geometries: Implications for Improved Sub-Salt Exploration*
By
Markus Mohr1, Peter A. Kukla1, Janos L. Urai1, and Georg Bresser2
Search and Discovery Article #40214 (2006)
Posted September 30, 2006
*Oral presentation at AAPG Annual Convention, Houston, Texas, April 9-12, 2006.
Click to view presentation in PDF format.
1RWTH Aachen University, Aachen, Germany ( [email protected] )
2Formerly Gaz de France Production Exploration Germany GmbH, Germany; now Wintershall AG.
Abstract
The improved understanding of the structural,
sedimentary and salt-tectonic evolution of salt structures and knowledge of the
position and amount of subsurface salt has significant effects on seismic
modelling and depth conversion. The use of this information advances the
prediction of potential Upper Permian gas reservoirs in the intracontinental
sub-salt sequences in northern Germany.
High-quality seismic data enable us to present an
integrated genetic interpretation of salt-structure geometries and their
associated sedimentary patterns. We combine 2D and 3D seismic interpretation of
pre-stack depth-migrated data with 2D and 3D kinematic and geometrical
retro-deformation in order to restore and illustrate salt tectonic processes
through time, unravel their tectonic trigger mechanism and reveal the respective
sedimentary response.
This study identifies several salt wedges formed by
lateral extrusions during periods of diapir emergence and reduced sediment
accumulation. High-resolution seismic mapping and well-log analysis of the
sedimentary stacking patterns show that the effects of syn-sedimentary salt
movement with respect to accommodation development and salt flow are consistent
with the regional structural and stratigraphic framework. Additionally, bedded
primary evaporites (halite) in near-diapir strata of peripheral sinks show
extreme thicknesses of salt-sediment interbeds. We suggest that saline brine was
supplied to a formerly arid landscape through diapir dissolution by groundwater.
Diapiric growth and the developing relief of the peripheral sink controlled
preservation and salt accumulation of the bedded salt units. These near-diapir
sequences form potential hydrocarbon traps and thus represent an alternate
exploration target in most salt-rich hydrocarbon provinces.
Selected Figures
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W-E cross section (from 3D data) across
a diapir with complex geometry ( |
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W-E seismic profile across a diapir
showing lateral extrusions (three preserved |
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Late Triassic |
