Artículos de revistas
2.5-d True-amplitude Migration And Demigration
Registro en:
Journal Of Seismic Exploration. , v. 6, n. 02/03/15, p. 159 - 180, 1997.
9630651
2-s2.0-0031399962
Autor
Martins J.L.
Schleicher J.
Tygel M.
Santos L.T.
Institución
Resumen
Kirchhoff-type migration and demigration for three dimensions are exceedingly expensive processes in laterally inhomogeneous media due to the intense numerics required. For simpler types of media, however, the formulas to be implemented simplify considerably. For 3-D in-plane wave propagation in 2-D media, i.e., the 2.5-D situation, 2-D ray tracing is sufficient for full 3-D true-amplitude migration or demigration. In 1-D media, both imaging operations require the solution of certain integrals of a semi-analytic character which can be implemented in an even cheaper way. For some specific velocity distributions (such as constant velocity, constant velocity gradient, constant gradient of quadratic slowness and constant gradient of logarithmic velocity) fully analytic expressions can be derived. If the velocity distribution in the true earth model can be reasonably well represented by one of the considered situations, a very fast approximate true-amplitude Kirchhoff-type migration can be performed. Moreover, simple models in which the algorithms perform fast and accurately can be of great value for (a) validating the algorithms so as to ensure correct results in the desired realistic situations and (b) gaining insight on how to interpret the results. 6 02/03/15 159 180 Bleistein, N., Two-and-one-half dimensional in-plane wave propagation (1986) Geophys. Prosp., 34, pp. 686-703 Bleistein, N., On the imaging of reflectors in the earth (1987) Geophysics, 52, pp. 931-942 Bleistein, N., Cohen, J.K., Hagin, F.G., Two and one-half dimensional Born inversion with an arbitrary reference (1987) Geophysics, 52, pp. 26-36 De Castro, M.A., Červený, V., 3-D inversion of seismic reflection data using dynamic ray tracing (1991) 2nd Ann. Internat. Brazil. Geophys. Soc. Mtg., pp. 811-816. , Expanded Abstr Newman, P., Divergence effects in a layered earth (1973) Geophysics, 38, pp. 481-488 Schleicher, J., Tygel, M., Hubral, P., 3-D true-amplitude finite-offset migration (1993) Geophysics, 58, pp. 1112-1126 Schneider, W.A., Integral formulation for migration in two and three dimensions (1978) Geophysics, 43, pp. 49-76 Tygel, M., Schleicher, J., Hubral, P., Pulse distortion in depth migration (1994) Geophysics, 59, pp. 1561-1569 Tygel, M., Schleicher, J., Hubral, P., A unified approach to 3-D seismic reflection imaging. Pt. II: Theory (1996) Geophysics, 61, pp. 759-775