Acoustic anisotropic wavefields through perturbation theory

Handle URI:
http://hdl.handle.net/10754/575816
Title:
Acoustic anisotropic wavefields through perturbation theory
Authors:
Alkhalifah, Tariq Ali ( 0000-0002-9363-9799 )
Abstract:
Solving the anisotropic acoustic wave equation numerically using finite-difference methods introduces many problems and media restriction requirements, and it rarely contributes to the ability to resolve the anisotropy parameters. Among these restrictions are the inability to handle media with η<0 and the presence of shear-wave artifacts in the solution. Both limitations do not exist in the solution of the elliptical anisotropic acoustic wave equation. Using perturbation theory in developing the solution of the anisotropic acoustic wave equation allows direct access to the desired limitation-free solutions, that is, solutions perturbed from the elliptical anisotropic background medium. It also provides a platform for parameter estimation because of the ability to isolate the wavefield dependency on the perturbed anisotropy parameters. As a result, I derive partial differential equations that relate changes in the wavefield to perturbations in the anisotropy parameters. The solutions of the perturbation equations represented the coefficients of a Taylor-series-type expansion of the wavefield as a function of the perturbed parameter, which is in this case η or the tilt of the symmetry axis. The expansion with respect to the symmetry axis allows use of an acoustic transversely isotropic media with a vertical symmetry axis (VTI) kernel to estimate the background wavefield and the corresponding perturbation coefficients. The VTI extrapolation kernel is about one-fourth the cost of the transversely isotropic model with a tilt in the symmetry axis kernel. Thus, for a small symmetry axis tilt, the cost of migration using a first-order expansion can be reduced. The effectiveness of the approach was demonstrated on the Marmousi model.
KAUST Department:
Physical Sciences and Engineering (PSE) Division; Environmental Science and Engineering Program; Earth Science and Engineering Program
Publisher:
Society of Exploration Geophysicists
Journal:
GEOPHYSICS
Issue Date:
Sep-2013
DOI:
10.1190/geo2012-0391.1
Type:
Article
ISBN:
9781629937908
Appears in Collections:
Articles; Environmental Science and Engineering Program; Environmental Science and Engineering Program; Physical Sciences and Engineering (PSE) Division; Physical Sciences and Engineering (PSE) Division; Earth Science and Engineering Program; Earth Science and Engineering Program

Full metadata record

DC FieldValue Language
dc.contributor.authorAlkhalifah, Tariq Alien
dc.date.accessioned2015-08-24T09:26:59Zen
dc.date.available2015-08-24T09:26:59Zen
dc.date.issued2013-09en
dc.identifier.isbn9781629937908en
dc.identifier.doi10.1190/geo2012-0391.1en
dc.identifier.urihttp://hdl.handle.net/10754/575816en
dc.description.abstractSolving the anisotropic acoustic wave equation numerically using finite-difference methods introduces many problems and media restriction requirements, and it rarely contributes to the ability to resolve the anisotropy parameters. Among these restrictions are the inability to handle media with η<0 and the presence of shear-wave artifacts in the solution. Both limitations do not exist in the solution of the elliptical anisotropic acoustic wave equation. Using perturbation theory in developing the solution of the anisotropic acoustic wave equation allows direct access to the desired limitation-free solutions, that is, solutions perturbed from the elliptical anisotropic background medium. It also provides a platform for parameter estimation because of the ability to isolate the wavefield dependency on the perturbed anisotropy parameters. As a result, I derive partial differential equations that relate changes in the wavefield to perturbations in the anisotropy parameters. The solutions of the perturbation equations represented the coefficients of a Taylor-series-type expansion of the wavefield as a function of the perturbed parameter, which is in this case η or the tilt of the symmetry axis. The expansion with respect to the symmetry axis allows use of an acoustic transversely isotropic media with a vertical symmetry axis (VTI) kernel to estimate the background wavefield and the corresponding perturbation coefficients. The VTI extrapolation kernel is about one-fourth the cost of the transversely isotropic model with a tilt in the symmetry axis kernel. Thus, for a small symmetry axis tilt, the cost of migration using a first-order expansion can be reduced. The effectiveness of the approach was demonstrated on the Marmousi model.en
dc.publisherSociety of Exploration Geophysicistsen
dc.titleAcoustic anisotropic wavefields through perturbation theoryen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentEnvironmental Science and Engineering Programen
dc.contributor.departmentEarth Science and Engineering Programen
dc.identifier.journalGEOPHYSICSen
kaust.authorAlkhalifah, Tariq Alien
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