Revisiting a Salt Stock Family of the North German Basin by Applying Seismic CRS-Processing
Heinz-Juergen Brink, Dirk Gajeswki, Mikhail Baykulov, and Mi-Kyung Yoon
University of Hamburg / Institute of Geophysics/ Wave Inversion Technology, Hamburg, Germany
A seismic reprocessing of data from a salt stock family in the North German Basin provided new insight into the structural evolution of this area. The Common Reflection Surface (CRS) stack technology was applied to reprocess the reflection data acquired by the hydrocarbon industry in the 1980s. Due to the low fold of these data and the complex geology in the study area severe imaging challenges were encountered when the data were initially processed using conventional CMP stacking. The CRS technology is particularly suited for low fold data in complex areas since it automatically builds physically correct super gathers even if dipping structures are present. This leads to a considerably improved signal-to-noise ratio in the CRS stack compared to CMP stacked sections. Moreover, the CRS parameters obtained during the stack form the foundation for a robust reflection tomography used for velocity model building. These models allowed the application of pre-stack and post-stack depth migration. The obtained depth images provided structural details not seen before, motivating an alternative view on the structural setting of the area. The image of the Jurassic salt plug, originally seen as so-called daughter salt stock (2nd generation), indicates tectonics similar to observations in a region within the North German Basin, where reverse faulting plays a major role in the evolution of the salt structures. As a consequence shortening of the Mesozoic strata was included into the revised interpretation of the area under investigation. The new depth images also allowed an updated look on the petroleum system, which indicates new possible exploration targets.
AAPG Search and Discovery Article #90091©2009 AAPG Hedberg Research Conference, May 3-7, 2009 - Napa, California, U.S.A.