Internal multiple prediction and subtraction: VSP, pre-and post-stack seismic data examples

Andrew Iverson, Kristopher A. Innanen, Daniel O. Trad, Marianne Rauch

A land dataset has been donated to CREWES due to a significant issue with internal multiples. This dataset includes well logs, a VSP and 3D seismic data. Synthetic modeling and tie to the 3D data demonstrate that internal multiple problems are present. A synthetic data test shows that inverse scattering series internal multiple attenuation can be used to remove some of the internal multiple energy. The learnings from this synthetic study are applied to both the VSP and 3D data. Extension to these data has proved to be challenging, though it is difficult to quantify results, and there are still learnings from the analysis. While there are minimal assumptions for the inverse scattering method, it is possible that that of low noise has been violated in this data set. Despite these difficulties there are locations throughout the 2D crossline test where there appear to be improvements in coherency, though this is largely a qualitative observation.