Inventors:
Bin Wang - Katy TX, US
Francois Audebert - Houston TX, US
International Classification:
G01V 1/28
G01V 1/38
Abstract:
A low-cost general method to perform subsalt velocity analysis is provided. For instances where sediment velocity structure is relatively simple, the method includes a single one-time redatuming to the base of salt, using existing prestack wave equation tools. For instances where the sediment velocity structure has a variable topography, the method includes multi-step redatuming to the base of salt. The method is designed to completely remove the salt-sediment overburden effects, and redatum the surface seismic data to a flat arbitrary subsalt datum, removing the complexity of the wavefield caused by the salt bodies. Once having obtained a simplified wavefield by stripping off the effects of the complex overburden, less expensive Kirchhoff imaging algorithms are employed for performing subsalt velocity model building.