3D CRS Velocity Depth Model Building and Depth Processing in Overthrust Geology

The Molasse Basin in Upper Austria is a very mature exploration area. The main problem is the low fold 3D seismic database with a generally good imaging in the northern Molasse Foreland basin and fair to poor imaging in the imbricated Molasse and alpine Flysch areas to the South. As the exploration targets are moving south the image quality in the southern part becomes more and more important. Failure of prestack time migration methods due to the low fold led to the application of Common Reflection Surface (CRS) stacking methods to improve imaging in the Imbricates and in and under the Flysch as well as derive a more reliable interval velocity model in depth.