| Autor: |
M. Reinier, G. Lambaré, P. Guillaume, A. Cavalié, B.M. Bruun, M.I. Adamsen |
| Rok vydání: |
2013 |
| Předmět: |
|
| Zdroj: |
London 2013, 75th eage conference en exhibition incorporating SPE Europec. |
| ISSN: |
2214-4609 |
| Popis: |
Ray based migration velocity analysis from pre-stack seismic reflection data is based on the characterization of the migrated reflected events by their position, dips and residual move-out. Such approaches update the depth velocity model through an optimization process, where the residual move-out of the picked migrated events is minimized while obeying some regularization constraints related to the depth or to the shape of some horizons or to the smoothness or structural conformity of the velocity field. We propose to introduce an additional term in the cost function involving the dip of kinematically migrated locally coherent events. The velocity is then updated to match the expected dip of the re-migrated offset-dependent events. We develop here the conceptual aspects of this new slope tomography and present a first application, on a North Sea dataset, to the characterization of very shallow channels creating pull-up and pull-down effects in deeper parts of the migrated image. Due to the very limited offset range of the residual move-out picks in shallow subsurface, these effects could not be solved by residual move-out based tomography. We demonstrate that the introduction of the dip-constrained inversion allows the correction of these pull-up and pull-down effects, resulting in improved depth imaging. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
