Velocity model building by wavefield-continuation imaging in the deepwater Gulf of Mexico

摘要

Wavefield-continuation-based migration algorithms that downward extrapolate the 3Dprestack wavefield (commonly known as "wave-equation migration") have been recently shown to produce better imaging results than Kirchhoff migration in many synthetic and real data cases (Popovici, 2000). Wavefield-continuation methods are potentially more accurate and robust because they are based on the full wave equation and not on an asymptotic solution based on ray theory. In addition, wavefield-continuation methods handle multi-pathing naturally in contrast to Kirchhoff methods, focusing and defocusing effects of velocity variations are correctly modeled, antialiasing is handled implicitly, and amplitudes are consistent with the wave equation.