Acoustic & Elastic Seismic Modeling and Imaging
by Phil Bording and Larry Lines
Duration: Two days
Intended Audience: Entry level to Intermediate
Prerequisites (Knowledge/Experience/Education Required): The course will show many examples for the seismic modeling and migration some with animations. The addition of elastic modeling and migration will require presenting the standard material on elastic waves. Students today should be comfortable with these ideas.
This course deals with the analysis and application of the acoustic and elastic wave equations in exploration seismology. In particular, the course focuses on the finite-difference modeling of the full wave equation and its application to forward modeling and migration. Simple mathematical derivations are used to numerically describe the partial differential equations of wave propagation and the corresponding boundary conditions. The acoustic, acoustic variable density, and elastic wave equations are presented to develop their use as complete wave equations for modeling. The use of seismic modeling for the study of interpretation problems is reviewed. Anisotropy and Q in modeling for understanding of complex seismic data issues is also considered. Following the research of Whitmore, McMechan, and Baysal et al., it is shown how wave modeling can be transformed into reverse-time migration methods by backward propagation of the seismic wavefield from the recording surface to the reflector depth. Many imaging examples are presented using computer visualization tools to illustrate seismic exploration examples. Data examples show enhanced reverse-time migration images of complicated geological structures such as salt intrusions and overthrust folds. This course describes aspects of 3-D reverse-time migration, prestack vs. poststack migration, and the possible solutions of the problem through "wave machines".
- Introduction to the acoustic and elastic wave equations
- Wave equation modeling: "The Numerical Ripple Tank"
- Wave equation modeling for interpretation analysis, including anisotropy and Q
- Acoustic reverse-time migration
- Poststack migration applications
- Prestack migration applications
- Data examples include Gulf of Mexico salt intrusions, offshore Newfoundland, Alberta and Wyoming overthrust plays
- New developments