REVERSE TIME MIGRATION OF TTI MEDIA USING THE DECOMPOSED WAVEFIELD

摘要

Reverse time migration (RTM) produces complex structure imaging with full wavefield information. This is the highest-precision imaging method to date. Compared with isotropic media RTM, imaging accuracy is assured by adding anisotropic constraints to seismic wavefields. Because of the sharp changes of velocity in the model, seismic wavefields generate strong reflection energy which causes noise or even false structure in the migration results. The main controlling factors of the anisotropic parameters were analyzed in this study by numerical simulation. The Hilbert transform was used to decompose the full wavefields in tilted transversely isotropic (TTI) media. The migration results were produced by cross-correlation of the decomposed wavefield imaging condition. Numerical examples show that the method obtains imaging results with high signal-to-noise ratio in TTI media.