Wave-Equation Migration Velocity Analysis by Non-Stationary Focusing

Wave-equation migration velocity analysis (WEMVA) is a non-linear optimization process that aims at estimating seismic velocities from reflection data using the wave equation. One important issue in Born-approximation-based WEMVA is preparation of an image perturbation free of cycle-skipping during each linear update. I show that this step can be accomplished by estimating the non-stationary slope of defocused events in subsurface offset gathers (ODCIG). The analysis also compares and unifies two popular WEMVA approaches, namely differential semblance optimization (DSO) and differential residual migration (DRM). The proposed method could be considered as an improved DSO implementation that overcomes some of its limitations by incorporating concepts from DRM.

[1]  Tingting Wu,et al.  International Journal of C 2013 Institute for Scientific Numerical Analysis and Modeling Computing and Information an Optimal 9-point Finite Difference Scheme for the Helmholtz Equation with Pml , 2022 .

[2]  A. Tarantola.  Inversion of seismic reflection data in the acoustic approximation , 1984 .

[3]  Timothy A. Davis,et al.  Algorithm 832: UMFPACK V4.3---an unsymmetric-pattern multifrontal method , 2004, TOMS.

[4]  William W. Symes,et al.  Automatic velocity analysis via shot profile migration , 2008 .

[5]  W. Symes,et al.  Angle‐domain common‐image gathers for migration velocity analysis by wavefield‐continuation imaging , 2004 .

[6]  Paul Sava,et al.  Adjoint wave-equation velocity analysis , 2006 .

[7]  Paul Sava,et al.  Wave-equation migration velocity analysis. I. Theory , 2004 .

[8]  Sergey Fomel,et al.  Applications of plane-wave destruction filters , 2002 .

[9]  Paul Sava,et al.  Wave‐equation migration velocity analysis. II. Subsalt imaging examples , 2004 .

[10]  Sergey Fomel,et al.  Velocity continuation and the anatomy of residual prestack time migration , 2003 .

[11]  P. Williamson,et al.  On the gradient artifacts in migration velocity analysis based on differential semblance optimization , 2010 .

[12]  Paul Sava,et al.  Angle-domain common-image gathers by wavefield continuation methods , 2003 .

[13]  Robert H. Stolt,et al.  A prestack residual time migration operator , 1996 .

[14]  Soo-Chang Pei,et al.  Closed-form design of maximally flat FIR Hilbert transformers, differentiators, and fractional delayers by power series expansion , 2001 .

[15]  Paul Sava,et al.  Prestack residual migration in the frequency domain , 2003 .