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In this paper, we investigate phases in different one way wave equation based migration algorithms. We found that poststack migrations preserve the characteristics of the input wavelet. However, like Kirchhoff migration, prestack shot and plane wave migration require a phase rotation to match the phase of the image to that of the input data. We use a single impulse response and a flat reflector model to demonstrate our conclusions.
Anisotropic depth migration (ADM) has become more commonplace over the past four years. The data-processing examples detailed here illustrate the robustness of the method in a variety of structured settings in the Alberta Foothills. The public-domain structural line, the Husky/Talisman dataset, illustrates subtle improvements in imaging with a dramatic improvement in accuracy of horizon depths when ADM is applied to these data. A 3D survey in a difficult imaging area, Nordegg/Chungo, shows significant healing of broken basement reflectors when we correct for anisotropy in the complex-dipping clastic overburden. Finally, in the Blacstone area where we observe intense folding in the near surface, comparisons between poststack time migration, prestack time migration, prestack depth migration, and prestack anisotropic depth migration in the Blackstone area show the similar step-change improvements as we imrove the technology of our algorithm.
For example, under have been proposed which utilize iterative prestack migration.
Perform well for steep dips and extreme velocity done today.
We present a common offset multiarrival final laser-beam Q-migration (Q-beam) algorithm, which maintains high frequency and accuracy with improved performance over standard Gaussian beam migration. This is achieved by a laser beam method, which limits the beam spread similar to a laser. Such an approach handles large lateral velocity variations without imposing dip or multiarrival limitations for imaging. Furthermore, our method applies Q amplitude loss and phase-shift compensation in the Gaussian-beam multiarrival imaging condition, including interpolation in the inverse Q weighted travel time T* domain. Overhead cost for this approach when compared against standard Gaussian or Kirchhoff migration is negligible. Laser beam migration preserves broadband data frequency and is appropriate as a final imaging tool as presented by our broadband data example. The validity of our final laser beam Q-migration is demonstrated with our 2D synthetic data set and 3D field data set, compared against standard Gaussian beam and Q-Kirchhoff migration.