Wave equation depth migration using complex Padé approximation

ull-wave-equation depth extrapolation for migration

Most of the traditional approaches to migration by downward extrapolation suffer from inaccuracies caused by using one-way propagation, both in the construction of such propagators in a variable background and the suppression of propagating waves generated by, e.g., steep reflectors. We present a new mathematical formulation and an algorithm for downward extrapolation that suppress only the eva...

Wave-equation migration velocity analysis beyond the Born approximation

The Born approximation is based on the assumption of small slowness perturbation. We investigate the limits of the Born approximation when applied to wave-equation migration velocity analysis and propose two new schemes which allow for larger slowness anomalies, while improving accuracy and increasing stability. The new schemes are based on linearizations of exponential functions using bilinear...

Wave-Equation Wavefront Migration

The wave-equation wavefront migration (WWM) is a potentially efficient form of wave equation migration, where the finite-difference stencil is only applied around the leading portion of the wavefront. WWM has the accuracy of wave-equation migration, fewer aliasing and migration artifacts, and can potentially be much faster than the standard reverse-time migration. The potential drawbacks are th...

Wave-equation prestack depth migration for sub-basalt P and converted wave imaging

We apply 2-D wave-equation prestack depth migration to a North Sea basalt dataset. High velocity and impedance contrasts across a basalt layer causes low P-wave reflection signal-to-noise ratio under the basalt. We first migrate the P-wave data with a provided depth velocity model, and then replace sub-basalt P-wave velocity with a simple estimate of shear wave velocity and migrate locally-conv...

On Padé Approximation of Some Practical Functions