GNGTS 2013 - Atti del 32° Convegno Nazionale

a more realistic synthetic dataset. The multiples recorded in the data were successfully treated as a source of valuable information of the subsurface discontinuities and it was possible to create a migrated section using this new information. The main issue related to the migration of multiples is the cross-talk between primaries and multiples relative to different reflectors. More studies are needed to better characterize the cross- talk events and to implement some techniques for their removal or attenuation even though their analysis in the A-CIG domain seems to promising. Nevertheless, the performed tests showed that the seismic image constructed using the surface-related multiple reflections could be very useful to complement the conventional migrated section. As a matter of fact, the illumination provided by the multiples is often wider than the one of the primaries. Moreover, the multiples arrive at the subsurface discontinuities with different angles with respect to the primaries, thus providing additional information that could be useful for the migration velocity analysis. Acknowledgements. This work has been done in collaboration with Eni. The authors would like to thank Eni to the permission to publish this work. References Alkhalifah, T., Zuberi, M.; 2011: Imaging by Forward Propagating the Recorded Data - An Analysis . 73rd EAGE Conference & Exhibition incorporating SPE EUROPEC 2011 Vienna, Austria, 23-26 May 2011 Berkhout, A.J., Vershuur, E.; 2006: Imaging of multiple reflections. Geophysics, 71, no. 4, SI209-SI220. Claerbout, J. F.; 1971: Toward a unified theory of reflector mapping . Geophysics, 36, no. 3, 467-481. Guitton, A.; 2002: Shot-profile migration of multiple reflections . Stanford Exploration Project, Report 111. Lipari, V., Fortini, C., Spadavecchia, E., Bienati, N.; 2012: Prediction of surface-related and inter-bed multiples via Kirchhoff extrapolation . Istanbul 2012 - International Geophysical Conference and Oil & Gas Exhibition: pp. 1-4. Muijs, R., Robertsson, J. O. A., Holliger, K.; 2007: Prestack depth migration of primary and surface-related multiple reflections: Part I – Imaging . Geophysics 72, S59-S69. Shaoping, L., Whitmore, N.D., Valenciano, A.A., Chemingui, N.; 2011: Imaging of Primaries and Multiples with 3D SEAM Synthetic . Verschuur, E.; 2006: Seismic multiple removal techniques - past, present and future . EAGE publications, ISBN 90-73781- 51-5. Verschuur, D.J., Berkhout, A.J., Wapenaar, C.P.A.; 1992: Adaptive surface-related multiple elimination . Geophysics 57, 1166-1177. Yilmaz, O.; 2011: Seismic Data Analysis: Processing, Inversion, and Interpretation of Seismic Data . Society of Exploration Geophysicists, ISBN 978-1-56080-094-1 Fig. 3 – Angle gathers panels from the Sigsbee2b dataset with the conventional migration (left) and with the migration of multiples (right). The yellow arrows indicate the events associated with the cross-talk noise. It is possible to notice that for the case of the multiples migration the energy is concentrated at smaller angles than in the case of the conventional migration. 39 GNGTS 2013 S essione 3.1