AAPG ANNUAL CONFERENCE AND EXHIBITION
Making the Next Giant Leap in Geosciences
April 10-13, 2011, Houston, Texas, USA
Geological Principles of Imaging Permian Salt Bodies in the North Sea and Irish Sea
(1) Subsurface, Centrica, Windsor, United Kingdom.
The advent of 3D seismic and then pre-stack depth migration has improved the seismic interpreter’s knowledge of salt bodies and revealed many sub-salt and salt flank hydrocarbon plays. The huge leaps in processing power and introduction of migration algorithms like Reverse Time Migration has helped advance the understanding of many salt features, but this has been at a price. Imaging salt bodies has always been a balance of quality against time and cost. As surveys get bigger and velocity analyses get more automated, then geological quality control becomes an even more critical factor in the processing of seismic and interpretation of structure. However, too often sub-surface professionals rely too heavily upon advanced processing algorithms and automated velocity picking to image and build their structural models. Regrettably, this sometimes results in basic geological principles taking second place to the new technology, which inevitably results in a poorly integrated and geologically questionable subsurface model.
This presentation contrasts salt body interpretation across several basins around the UK and Gulf of Mexico and demonstrates how simple geological understanding can sometimes speed up the construction of complex velocity models and improve the understanding of salt behaviour and the subsurface.