2019-08-292019-08-292008VALENTE, Leandro da Silva Sadala. Estimativa de modelo de velocidade em profundidade a partir de velocidades de migração em tempo. Orientador: Jessé Carvalho Costa. 2008. 55 f. Trabalho de Curso (Bacharelado em Geofísica) – Faculdade de Geofísica, Instituto de Geociências, Universidade Federal do Pará, Belém, 2008. Disponível em: http://bdm.ufpa.br/jspui/handle/prefix/1752. Acesso em:.http://bdm.ufpa.br/jspui/handle/prefix/1752One of the major challenges to seismic imaging in complex geological regions is velocity model building in depth. If lateral variation in the propagation velocity is moderate, a depth velocity model can be build starting from time migration velocities. I review the theoretical relation between these velocities using the paraxial ray theory. The estimation of depth velocities from time migration velocities is unstable. I implement regularized versions of the time to depth conversion based on Dijkstra-like fast marching methods. Two more e cient variations from the original algorithm proposed recently in the literature are evaluated. The relation between the polynomial degree and the regularization value for the least-squares problem associated with the wavefront interpolation are determined. Finally, I test these algorithms on 2D synthetic data and compare the results obtained by three ray tracing algorithms.Acesso AbertoProspecção SísmicaVelocidades de migração em tempoConversão tempo-profundidadeModelo de profundidade em velocidadeCNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOFISICATrabalho de Curso - Graduação - Monografia