High Quality Separation of Simultaneous Sources by Sparse Inversion

This paper demonstrates a method of producing pre-stack gathers from blended acquisition data that are as noise-free as gathers from conventional acquisition. Filtering out the interference from the overlapping shots and stacking the data are fairly effective in attenuating the interference from blended shots. However high-quality separation of the interference from the pre-stack data would make the data more suitable for amplitude dependent analysis, such as that for amplitude-versus-offset, time-lapse measurements, and fracture detection. The method presented here produces seismic records in which the interference is attenuated to the point that it is well below the background noise. This high quality attenuation is achieved by using a sparse inversion process that solves a modified version of Berkhout's matrix system, allowing the source responses to be separated for high quality amplitude measurements. The success of this source separation step in the data processing of blended acquisition means we can produce results with a quality that is comparable to that of conventional acquisition. Furthermore, this method improves the data quality while retaining the lower cost and higher productivity of ISSTM acquisition when compared with conventional acquisition.