Full-waveform inversion (FWI) has been implemented mostly for isotropic media, with extensions to anisotropic models typically limited to acoustic approximations. Here, we develop elastic FWI for transmitted waves in 2D heterogeneous VTI (transversely isotropic with a vertical symmetry axis) media. The model is parameterized in terms of the P- and S-wave vertical velocities and the P-wave normal-moveout and horizontal velocities. To test the FWI algorithm, we introduce Gaussian anomalies in the Thomsen parameters of a homogeneous VTI medium and perform FWI of transmission data for different configurations of the source and receiver arrays. The inversion results strongly depend on the acquisition geometry and the aperture because of the parameter trade-offs. In contrast to acoustic FWI, the elastic inversion helps constrain the S-wave vertical velocity, which for our model is decoupled from the other parameters.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: We are grateful to themembers of the A(nisotropy) and i(maging)teams at CWP and to Gerhard Pratt (University of WesternOntario), Tariq Alkhalifah (KAUST), Daniel Kohn (Universityof Kiel), Ken Matson (Shell), and Jon Sheiman (contractor,Shell), for fruitful discussions. We would also like tothank John Stockwell (CWP) and Paul Martin (Dept. of Mathematics,CSM) for help with mathematical issues. This workwas supported by the Consortium Project on Seismic InverseMethods for Complex Structures at CWP and by the CIMMMProject of the Unconventional Natural Gas Institute at CSM.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.