Depth Imaging and Velocity Model Construction

A complete imaging course, concentrating on visual concepts rather than equations. Difference between time and depth imaging, depth conversion.Wave and Ray based depth imaging correcting for velocity variation and complex sub-surface. Algorithm choice: Kirchhoff single/multi arrival, Beam versus wavefield methods (including reverse time migration), least-squares migration.

Role of interpreter in velocity model building and quality control

• Prestack migration, gather generation and velocity updates

• Anisotropy including VTI, TTI, orthorhombic cases.

• Full-Waveform Inversion

• Data preparation and initial quality controls

• Diving wave and reflection-based inversion schemes

• Quality control and common pitfalls.

• Tomography – grid or layer based, hybrid methods

• Case histories: Scott Field, North Sea Gas Basin, Sub-salt Gulf of Mexico.

• Additional uses of seismic velocities: e.g. imaging, pore pressure, depthing

Future developments: Imaging with multiples, Elastic imaging, Q migration