Uncertainties in local anisotropy estimation from multi-offset VSP Data

We have quantified the errors associated with VTI parameter estimation using multi-offset VSP data. Two common methods, P-wave slownesses only and slowness-polarization are investigated. Estimation errors are expressed in terms of the magnitude of the earth anisotropy, uncertainties related to first...

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Main Authors: Asgharzadeh, Mehdi, Bona, Andrej, Pevzner, Roman, Urosevic, Milovan, Gurevich, Boris
Other Authors: EAGE
Format: Conference Paper
Published: EAGE 2012
Online Access:http://www.earthdoc.org
http://hdl.handle.net/20.500.11937/12241
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author Asgharzadeh, Mehdi
Bona, Andrej
Pevzner, Roman
Urosevic, Milovan
Gurevich, Boris
author2 EAGE
author_facet EAGE
Asgharzadeh, Mehdi
Bona, Andrej
Pevzner, Roman
Urosevic, Milovan
Gurevich, Boris
author_sort Asgharzadeh, Mehdi
building Curtin Institutional Repository
collection Online Access
description We have quantified the errors associated with VTI parameter estimation using multi-offset VSP data. Two common methods, P-wave slownesses only and slowness-polarization are investigated. Estimation errors are expressed in terms of the magnitude of the earth anisotropy, uncertainties related to first break pickings and maximum available source offset. For homogeneous overburden, P-wave slownesses technique can be used to estimate VTI parameters. We demonstrate that estimation errors of using only P-wave slownesses are significantly decreased as longer source offsets are included in the inversion algorithm. Larger offsets involve P-waves which propagate near horizontal at the receiver level and enhance the method's efficiency. An example synthetic VSP is presented next where P-wave slownesses technique successfully recovers VTI model parameters. In case of heterogeneous overburden, P-wave slowness-polarization technique seems to be a solution as there is no need to compute P-wave horizontal slownesses. However, we demonstrate that the errors of VTI parameter estimation using this technique are small only where the anisotropy is very weak (below 5%) and they are not improved by increasing the offset. Furthermore, wave interference effect on polarizations makes the method impractical even on noise free synthetic data.
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format Conference Paper
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institution Curtin University Malaysia
institution_category Local University
last_indexed 2025-11-14T06:58:27Z
publishDate 2012
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spelling curtin-20.500.11937-122412017-03-08T13:31:52Z Uncertainties in local anisotropy estimation from multi-offset VSP Data Asgharzadeh, Mehdi Bona, Andrej Pevzner, Roman Urosevic, Milovan Gurevich, Boris EAGE We have quantified the errors associated with VTI parameter estimation using multi-offset VSP data. Two common methods, P-wave slownesses only and slowness-polarization are investigated. Estimation errors are expressed in terms of the magnitude of the earth anisotropy, uncertainties related to first break pickings and maximum available source offset. For homogeneous overburden, P-wave slownesses technique can be used to estimate VTI parameters. We demonstrate that estimation errors of using only P-wave slownesses are significantly decreased as longer source offsets are included in the inversion algorithm. Larger offsets involve P-waves which propagate near horizontal at the receiver level and enhance the method's efficiency. An example synthetic VSP is presented next where P-wave slownesses technique successfully recovers VTI model parameters. In case of heterogeneous overburden, P-wave slowness-polarization technique seems to be a solution as there is no need to compute P-wave horizontal slownesses. However, we demonstrate that the errors of VTI parameter estimation using this technique are small only where the anisotropy is very weak (below 5%) and they are not improved by increasing the offset. Furthermore, wave interference effect on polarizations makes the method impractical even on noise free synthetic data. 2012 Conference Paper http://hdl.handle.net/20.500.11937/12241 http://www.earthdoc.org http://www.earthdoc.org/publication/publicationdetails/?publication=58906 EAGE fulltext
spellingShingle Asgharzadeh, Mehdi
Bona, Andrej
Pevzner, Roman
Urosevic, Milovan
Gurevich, Boris
Uncertainties in local anisotropy estimation from multi-offset VSP Data
title Uncertainties in local anisotropy estimation from multi-offset VSP Data
title_full Uncertainties in local anisotropy estimation from multi-offset VSP Data
title_fullStr Uncertainties in local anisotropy estimation from multi-offset VSP Data
title_full_unstemmed Uncertainties in local anisotropy estimation from multi-offset VSP Data
title_short Uncertainties in local anisotropy estimation from multi-offset VSP Data
title_sort uncertainties in local anisotropy estimation from multi-offset vsp data
url http://www.earthdoc.org
http://www.earthdoc.org
http://hdl.handle.net/20.500.11937/12241