Downward extrapolation of multi-component seismic data
Abstract
An evaluation of the problems involved in elastic seismic migration is presented. Elastic wave field extrapolated operators are presented that are applicable to a general three dimensional elastic and anisotropic medium. Although the elastic operators derived are stand alone elements and can be used in any migration scheme, they are developed to take part in the stepwise elastic inversion scheme proposed by Berkhout and Wapenaar. The advantages of multicomponent seismic acquisition are discussed. The necessity of multicomponent data in elastic processing is demonstrated by an example, and a global description of all modules in the stepwise elastic inversion scheme is given. Elastic P and S extrapolation operators are derived starting from the full elastic Kirchhoff-Helmholtz integral. An analysis of the contribution of the different elastic terms in the extrapolation process is presented. It is made clear that there are many different ways to generate extrapolation operators for a so called macro model. (Such a macro model represents a global description of the subsurface in terms of velocities and densities and must be estimated before the actual extrapolation step can be performed.) A quantitative error analysis of the extrapolation operators proposed is performed. The influence of macro model errors on the amplitudes of the extrapolated P and S wave fields is examined. The use of the elastic P and S extrapolation operators in redatuming and migration schemes is considered.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1992
- Bibcode:
- 1992PhDT........41H
- Keywords:
-
- Data Processing;
- Operators (Mathematics);
- P Waves;
- S Waves;
- Seismic Waves;
- Wave Propagation;
- Errors;
- Evaluation;
- Extrapolation;
- Green'S Functions;
- Mathematical Models;
- Geophysics