Processing of 4C data from Mahogany Field, Gulf of Mexico

Peter W. Cary, Rodney A. Couzens

Two marine 4-C OBC seismic lines were acquired over Mahogany Field in the Gulf of Mexico during the latter part of 1997 and early part of 1998 by Geco-Prakla, and these lines have been made available to the CREWES Project. The primary purpose of acquiring and processing the data was to determine if shear-wave energy could be recorded and imaged from the zone-of-interest below the large salt bodies. Standard time-domain converted-wave processing of the horizontal components of these lines, including provision for anisotropic layering effects and asymmetry between positive and negative offsets, has been performed. The data quality is generally very good, and most of the energy on the inline component appears to be generated by conversion from P to S at the reflector, as observed elsewhere in the world. This report focuses on some of the issues to do with statics, binning and velocities encountered in the standard time-domain processing of this complex structural 4-C data. This analysis uncovers some of the problems that will need to be resolved in the future in order to obtain a higher fidelity image with more sophisticated processing tools such as anisotropic prestack depth migration.