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Modified Boundary Conditions for Elastic Inversion of Active Land Seismic Data in VTI Media
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 78th EAGE Conference and Exhibition 2016, May 2016, Volume 2016, p.1 - 5
Abstract
Summary
Acoustic waveform inversion algorithms become inadequate to fit the seismic observations in presence of high contrast velocity subsurface structures.
While accounting for shear wave effects, the elastic approach with land seismic data is challenging because of the energetic ground roll, which are only sensitive to very shallow part of the earth model. Our theoretical analysis indicates that the modified boundary conditions avoid generating ground roll in vertically transversely isotropic media, hence, allows to focus the inversion on diving waves of the pre-processed seismic records.
The behavior of the waveform inversion with the modified boundary conditions in vertically transversely isotropic media is numerically analyzed based on the computations of the gradients of the misfit function.
This numerical study shows that the proposed approach is relevant to invert the long-to-intermediate wavelengths of the compressional velocities without relying on a ground roll filtering of the modeled data.
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