Artículos de revistas
Coherence measures in automatic time-migration velocity analysis
Registro en:
Journal Of Geophysics And Engineering. Iop Publishing Ltd, v. 9, n. 5, n. 569, n. 584, 2012.
1742-2132
WOS:000309545900013
10.1088/1742-2132/9/5/569
Autor
Maciel, JS
Costa, JC
Schleicher, J
Institución
Resumen
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Time-migration velocity analysis can be carried out automatically by evaluating the coherence of migrated seismic events in common-image gathers (CIGs). The performance of gradient methods for automatic time-migration velocity analysis depends on the coherence measures used as the objective function. We compare the results of four different coherence measures, being conventional semblance, differential semblance, an extended differential semblance using differences of more distant image traces and the product of the latter with conventional semblance. In our numerical experiments, the objective functions based on conventional semblance and on the product of conventional semblance with extended differential semblance provided the best velocity models, as evaluated by the flatness of the resulting CIGs. The method can be easily extended to anisotropic media. 9 5 569 584 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Brazilian agency FINEP Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Brazilian agency Petrobras Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)