High-Resolution Velocity Model-Building for Pre-Stack Depth Migration in the Nordsjøn Area, Norwegian North Sea

C043 High-Resolution Velocity Model-Building for Pre- Stack Depth Migration in the Nordsjøn Area Norwegian North Sea J.K. Fruehn* (GX Technology) H. Sherazi (GX Technology) P.B. Hardy (GX Technology) J. Tryti (Statoil) & N. Steinsland (Statoil) SUMMARY Gridded tomography is generally perceived as being very good at resolving velocities down to fine detail but when it comes to resolving very sharp contrasts such as at top chalk or top salt levels it breaks down giving way to the hybrid approach. In this gridded tomography is confined to certain velocity domains and another velocity estimation method such as flooding or vertical update