Spherical wave AVO response of isotropic and anisotropic media: Laboratory experiment versus numerical simulations
A spherical wave AVO response is investigated by measuring ultrasonic reflection amplitudes from a water/Plexiglas interface. The experimental results show substantial deviation from the plane-wave reflection coefficients at large angles. However there is an excellent agreement between experimental...
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| Format: | Thesis |
| Language: | English |
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Curtin University
2007
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| Online Access: | http://hdl.handle.net/20.500.11937/267 |
| _version_ | 1848743330521808896 |
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| author | Alhussain, Mohammed |
| author_facet | Alhussain, Mohammed |
| author_sort | Alhussain, Mohammed |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | A spherical wave AVO response is investigated by measuring ultrasonic reflection amplitudes from a water/Plexiglas interface. The experimental results show substantial deviation from the plane-wave reflection coefficients at large angles. However there is an excellent agreement between experimental data and full-wave numerical simulations performed with the reflectivity algorithm. By comparing the spherical-wave AVO response, modeled with different frequencies, to the plane-wave response, I show that the differences between the two are of such magnitude that three-term AVO inversion based on AVA curvature can be erroneous. I then propose an alternative approach to use critical angle information extracted from AVA curves, and show that this leads to a significant improvement of the estimation of elastic parameters. Azimuthal variation of the AVO response of a vertically fractured model also shows good agreement with anisotropic reflectivity simulations, especially in terms of extracted critical angles which indicated that (1) reflection measurements are consistent with the transmission measurements; (2) the anisotropic numerical simulation algorithm is capable of simulating subtle azimuthal variations with excellent accuracy; (3) the methodology of picking critical angles on seismograms using the inflection point is robust, even in the presence of random and/or systematic noise. |
| first_indexed | 2025-11-14T05:43:51Z |
| format | Thesis |
| id | curtin-20.500.11937-267 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T05:43:51Z |
| publishDate | 2007 |
| publisher | Curtin University |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-2672017-02-20T06:41:18Z Spherical wave AVO response of isotropic and anisotropic media: Laboratory experiment versus numerical simulations Alhussain, Mohammed AVA curves plane-wave response estimation of elastic parameters spherical wave AVO response A spherical wave AVO response is investigated by measuring ultrasonic reflection amplitudes from a water/Plexiglas interface. The experimental results show substantial deviation from the plane-wave reflection coefficients at large angles. However there is an excellent agreement between experimental data and full-wave numerical simulations performed with the reflectivity algorithm. By comparing the spherical-wave AVO response, modeled with different frequencies, to the plane-wave response, I show that the differences between the two are of such magnitude that three-term AVO inversion based on AVA curvature can be erroneous. I then propose an alternative approach to use critical angle information extracted from AVA curves, and show that this leads to a significant improvement of the estimation of elastic parameters. Azimuthal variation of the AVO response of a vertically fractured model also shows good agreement with anisotropic reflectivity simulations, especially in terms of extracted critical angles which indicated that (1) reflection measurements are consistent with the transmission measurements; (2) the anisotropic numerical simulation algorithm is capable of simulating subtle azimuthal variations with excellent accuracy; (3) the methodology of picking critical angles on seismograms using the inflection point is robust, even in the presence of random and/or systematic noise. 2007 Thesis http://hdl.handle.net/20.500.11937/267 en Curtin University fulltext |
| spellingShingle | AVA curves plane-wave response estimation of elastic parameters spherical wave AVO response Alhussain, Mohammed Spherical wave AVO response of isotropic and anisotropic media: Laboratory experiment versus numerical simulations |
| title | Spherical wave AVO response of isotropic and anisotropic media: Laboratory experiment versus numerical simulations |
| title_full | Spherical wave AVO response of isotropic and anisotropic media: Laboratory experiment versus numerical simulations |
| title_fullStr | Spherical wave AVO response of isotropic and anisotropic media: Laboratory experiment versus numerical simulations |
| title_full_unstemmed | Spherical wave AVO response of isotropic and anisotropic media: Laboratory experiment versus numerical simulations |
| title_short | Spherical wave AVO response of isotropic and anisotropic media: Laboratory experiment versus numerical simulations |
| title_sort | spherical wave avo response of isotropic and anisotropic media: laboratory experiment versus numerical simulations |
| topic | AVA curves plane-wave response estimation of elastic parameters spherical wave AVO response |
| url | http://hdl.handle.net/20.500.11937/267 |