An Automated 3D Method for Azimuthal Anisotropy Analysis in Marine Seismic Data

We present an automated and efficient method for estimating the azimuthal anisotropy parameters for large volumes of 3D marine data. The method is automated because it is data driven and it does not involve any picking of velocity or semblance. It involves mainly two steps: first, flattening the CMP gathers that have been NMO corrected to generate time-variant timeshifts; second, fitting these timeshifts to the azimuthal anisotropic traveltime equation to generate the velocity ellipticity and its direction. Using a recent survey that was acquired off Western Australia, we demonstrate that this method is able to obtain dense anisotropies and directions in large-scale areas in an automated way.