Multi-azimuth towed streamer 3D seismic in the Nile Delta, Egypt – processing solutions

Multi-azimuth or wide azimuth seismic is not a new technology, and has been with us for many years in the form of land, and ocean bottom surveys. The literature is rich with examples of how high-fold multi-azimuth data can produce stunning improvements over their single azimuth 3D equivalents (Rogno et al., 1999, Keggin et al., 2002, Gaus and Hegna, 2003, Arntsen and Thompson, 2003, Riou et al., 2005, Manley et al., 2006, Michell et al., 2006). We know from theory and case histories that multi-azimuth data will lead to improved signal to noise, improved multiple attenuation and improved illumination. However, because of approximations in current processing technology, the processing of multi-azimuth data will leave errors in the final imaged results. Simple stacking of the data, though surprisingly robust makes assumptions about data consistency between surveys and will likely not result in the most optimal image. This paper shows how multi-azimuth (MAZ) towed streamer data is processed in the Nile Delta, looks at some of the issues highlighted above and discusses the initial processing sequence to improve the combined subsurface image.