Full-waveform inversion in an anisotropic elastic earth - Can we isolate the role of density and shear wave velocity?
Type
Conference PaperAuthors
Guitton, A.Alkhalifah, Tariq Ali

KAUST Department
Earth Science and Engineering ProgramPhysical Science and Engineering (PSE) Division
Seismic Wave Analysis Group
Date
2017-03-13Permanent link to this record
http://hdl.handle.net/10754/663914
Metadata
Show full item recordAbstract
Five parameters are needed to describe VTI anisotropy in 2-D elastic media. With conventional streamer data, an optimal parameterization for full-waveform inversion (FWI) consists in using the horizontal velocity vh, the anellipicity parameter ζ, and the parameter that relates the horizontal-to-vertical velocity, ϵ. This parameterization, derived with a pseudo-acoustic formulation of the wave equation, minimizes crosstalks. We extend this analysis to the elastic case and wonder what are the effects of density and shearwave velocity on the inversion results if ignored. Using radiation patterns derived in the elastic case and a modified version of the Marmousi II model, we see that PP-waves are mostly helping to recover vh and ϵ, while PS-waves are mostly helping to recover ζ. For all scattering angles and wave modes, ϵ and ρ are strongly coupled. Keeping ρ and vs unchanged during the inversion is a valid strategy if their background models are good enough. For small vs and ρ errors, the vs perturbation will map into ζ while ρ will map into ϵ. For large errors, vs adversely affects the recovery of ζ and might leak into vh while ρ will preferentially leak into ϵ, then ζ and, in smaller proportions, into vh.Citation
Guitton, A., & Alkhalifah, T. (2016). Full-waveform Inversion in an Anisotropic Elastic Earth - Can We Isolate the Role of Density and Shear Wave Velocity? 78th EAGE Conference and Exhibition 2016. doi:10.3997/2214-4609.201601193Sponsors
We thank KAUST and the Center for Wave Phenomena sponsors for their financial s u pport. Antoine Guitton thanks GeoImaging Solutions Inc. for permission to publish this work.Publisher
EAGE PublicationsConference/Event name
78th EAGE Conference and Exhibition 2016: Efficient Use of Technology - Unlocking PotentialISBN
9789462821859ae974a485f413a2113503eed53cd6c53
10.3997/2214-4609.201601193