3d Complex Media Way Wave Algorithm

Numerical results demonstrate that the one-way wave equation modeling scheme exhibits sufficient accuracy in terms of primary reflected waves in comparison with the two-way wave equation scheme. The computational cost is greatly reduced by employing the one-way wave equation scheme. Moreover, only a rough velocity model is needed for implementing the one-way wave equation scheme in seismic modeling. Since the one-way wave equation modeling scheme can be considered as the inverse depth migration, we can use the current depth migration schemes and its codes.An efficient weighted quadratic-programming method is put into use to design optimum explicit operators. 3-D wavefields is extrapolated in depth by the 1-D explicit operators and McClellan transformation in this paper. The proposed scheme can image steeply dipping reflectors in media with lateral velocity variations, and no numerical azimuth anisotropy exists. The computational cost for the proposed scheme is about same as that of conventional implicit finite-difference methods.Accounting for both accuracy and computational efficiency, we use the explicit short extrapolation operator scheme in a complicated medium layer and the split step Fourier operators in a simple medium layer during depth extrapolations. Reflected coefficients are obtained by accounting for its variation with incident angles in the scheme.