| The reservoirs of the Hibernia oil field are located within the complexly faulted Hibernia rollover structure. The accurate positioning of faults and sedimentary boundaries is especially important for the successful extraction of available hydro-carbons. Seismic migration is a valuable processing tool in the accurate imaging of such complex geologic features. Frequency -wavenumber domain, phase-shift, and reverse-time poststack migrations are tested for their ability to image Hibernia seismic data. Reverse-time migration is tested as both a 2-D and 3-D migration, and offers particular advantages due to its generality and lack of dip limitations. This migration comparison is initially done using synthetic seismic data generated from 3-D finite-difference models of the Hibernia oil field. Successful finite-difference modeling requires consideration of numerical stability, grid dispersion, and available computational facilities.;Successful poststack migration requires an accurate input velocity model, and a complete inversion may be achieved by performing a velocity sensitivity analysis on the input seismic data. This analysis requires available well formation tops so that the migration layer depths may be least-squares fitted to the well tops by adjusting the velocities. This method assumes that the layers intersect the well and are easily identifiable on the seismic section. Reverse-time migrations of model data, and well lines from the Hibernia seismic data set, are optimized in this manner. |
