BEST PETROLEUM PAPER AT CONFERENCE

depth migration, wavefield extrapolation, explicit finite-difference operator, constrained operator, interpolation. An efficient 3D explicit finite-difference prestack depth migration* Summary An explicit, constrained operator is presented here for wavefield extrapolation in 3D wave equation depth migration. The migration cost and image quality benefit from its reduced number of independent coefficients within the operator, negligible numerical anisotropy, and flexibility that allows for different propagation angles and step sizes in the inline and cross-line directions. In order to further reduce the computational workload we dynamically select operator lengths and extrapolation step sizes based on the wavenumber of the wave components being migrated. The phase-shifted linear interpolation that we propose for interpolating the extrapolated wavefield is suitable for the explicit migration, and significantly improves the accuracy of the result when compared with the linear interpolation typically used in implicit migrations