Chapter 5: PS common-azimuth migration

Chapter 5 describes a downward-continuation method to migrate 3-D converted-wave data. This downward-continuation operator uses the stationary-phase approximation for the full 3-D prestack downward-continuation operator. This chapter demonstrates that is feasible to extend the existing common-azimuth downward-continuation to handle PS data. This PS common-azimuth operator uses two propagation velocity models for each of the wavefields.

Finally, I test the PS-CAM operator with the results obtained in Chapter 4 for the real 3-D OBS dataset from the Alba oil field. I compare two images. The first image is the result of using normal moveout plus stacking to obtain a common-azimuth cube. Second, the result obtained using the method developed in Chapter 4. The comparison between these two results show that the correct handling of irregular geometries before the migration yields to better image results.