We present a case study of enhanced imaging of wideazimuthdata from the Gulf of Mexico utilizing recent technologies;and we discuss the resulting improvements in imagequality, especially in subsalt areas, relative to previousresults. The input seismic data sets are taken from manylarge-scale wide-azimuth surveys and conventional narrowazimuthsurveys located in the Mississippi Canyon andAtwater Valley areas. In the course of developing the enhancedwide azimuth processing flow, the following threekey steps are found to have the most impact on improvingsubsalt imaging: (1) 3D true azimuth surface-related multipleelimination (SRME) to remove multiple energy, in particular,complex multiples beneath sa (2) reverse-time migration(RTM) based delayed imaging time (DIT) scans to updatethe complex subsalt velocity model; and (3) tilted transverseisotropic (TTI) RTM to improve image quality. Our researchfocuses on the depth imaging aspects of the project, withparticular emphasis on the application of the DIT scanningtechnique. The DIT-scan technique further improves theaccuracy of the subsalt velocity model after conventionalray-based subsalt tomography has been performed. We alsodemonstrate the uplift obtained by acquiring a wide-azimuthdata set relative to a standard narrow-azimuth data set, andhow orthogonal wide-azimuth is able to enhance the subsaltillumination.
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