In areas of complex geology, especially where fractures are present, azimuthal anisotropy should be seriously considered. Tilted Transverse Isotropy (TTI), which only considers polar anisotropy, is often not sufficient for correcting moveout fluctuations detected in different azimuthal sectors. Orthorhombic anisotropy (ORT), which can describe both azimuthal and polar anisotropy, provides a more comprehensive model than the simpler Transversely Isotropic (TI) model. In this paper we present a

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... thodology for ORT model building and imaging. The effectiveness of ORT imaging is demonstrated through its application to Orthogonal Wide Azimuth (OWAZ) data from the Gulf of Mexico (GoM). The process of ORT model building is introduced and orthorhombic tomography is applied to invert for azimuth-dependent anisotropic parameters. By resolving the inconsistencies in residual moveout for different azimuths, it is demonstrated that ORT imaging improves gather flatness in all azimuths and produces better image focusing.