Towards interactive seismic imaging with curvelets

International audienceWe present a new methodology towards interactive seismic imaging. A first seismic image is obtained with a prestack depth migration code run in a reference velocity model. The objective is to efficiently derive what the migrated section would be in a perturbed velocity model. Instead of migrating the full input data in the second velocity model, the reference migrated section is first decomposed in the curvelet domain. This provides coefficients associated to the representation of local plane waves and described by two positions, a direction and a central frequency. Perturbing the velocity model consists of de-migrating the local plane waves by ray tracing and re-migrating them in the second model. In practice, this simply leads to the shift of coefficients in the curvelet domain. Only the coefficients affected by the velocity perturbations have to be considered. The final section is then obtained by applying the inverse curvelet transform. As an initial example, this methodology is used on a 2-D zero-offset section migrated in a heterogeneous model. It allows for better understanding the sensitivity of a seismic image with respect to the velocity model used for migration