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Automatic Migration Velocity Analysis Applied to Direct Waves in a Crosswell Configuration
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 77th EAGE Conference and Exhibition 2015, Jun 2015, Volume 2015, p.1 - 5
Abstract
Summary
In the framework of Migration Velocity Analysis, only reflected events are usually taken into account. We define here Common Image Gathers through a minimization approach in the extended model, where subsurface offsets are introduced. It allows handling reflected, as well as transmitted waves. We apply the methodology defined in the image-domain to a Crosswell Seismic Profiling configuration in order to update the background velocity model containing the large scale structures. In contrast to reflected waves, where Common Image Gathers exhibit characteristic shapes, the energy is here mainly focused around a specific subsurface offset, depending on the migration velocity model. A smooth coherent gradient of the image-domain objective function is obtained for homogeneous 2D model, leading to an automatic convergence towards the correct velocity model. We present and discuss a crosswell application with a model containing a fault.
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