oa Towards Lateral Broadband

New acquisition techniques and the evolution of broadband processing in the past ten years have enabled the extension of the frequency bandwidth from the conventional three octaves bandwidth [10Hz–80 Hz] to a six octaves broadband bandwidth [2.5Hz–160Hz]. Despite this impressive achievement, some problems still remain:

1. The broadband processing sequence has become very complex.
2. This processing sequence makes a heavy use of sparse tau-p transforms in steps like receiver deghosting and regularization. However, the underlying assumption that a shot point can be locally decomposed in a few linear events can be questionable.
3. The lateral resolution has not increased in the same proportion as the vertical resolution.

In order to solve these problems, we show that we can obtain a significant increase in lateral resolution by using for the final imaging a least-squares migration with ghost and multiple modeling, allowing the deghosting, regularization and multiple attenuation being handled by the inversion. This is assessed on a real 3D dataset with depth-slices showing an increase in wavenumber bandwidth similar to the increase already obtained in frequency bandwidth.