Estimation of VTI parameters using slowness-polarization inversion of P- and SV-waves
Tamimi, N., Tsvankin, I. and Davis, T.L., 2015. Estimation of VTI parameters using slowness-polarization inversion of P- and SV-waves. Journal of Seismic Exploration, 24: 455-474. Ignoring anisotropy may cause serious distortions in the results of seismic data processing and interpretation. Although P-wave data provide valuable information for estimating anisotropy parameters, important additional constraints can be obtained from shear waves. Here, we present an extension of the slowness-polarization method for VSP data, in which we combine the vertical slownesses and polarization angles of P- and SV-waves. The algorithm is developed for VTI (transversely isotropic with a vertical symmetry axis) media, but it can be generalized for azimuthally anisotropic models. The weak-anisotropy approximation shows that adding SV-wave data generally stabilizes slowness-polarization inversion. In particular, SV-waves improve not only estimation of the anellipticity parameter 7 but also help constrain the coefficient 6, if propagation angles around 45° are available. The proposed technique is applied to a synthetic VSP data set generated using a finite-difference code. This test confirms that including SV-waves yields better inversion results than those obtained solely from P-wave data.
- Alkhalifah, T. and Tsvankin, I., 1995. Velocity analysis for transversely isotropic media.
- Geophysics, 60: 1550-1566.
- Backus, G.E., 1965. Possible form of seismic anisotropy of the upper most mantle under ocean. J.
- Geophys. Res., 70: 3429-3439.
- de Parscau, J., 1991. Relationship between phase velocities and polarization in transversely isotopic
- media. Geophysics, 56: 1578-1583.
- de Parscau, J. and Nicoletis, L., 1990. Tranverse isotropy estimation from multioffset VSPs.
- Expanded Abstr., 60th Ann. Internat. SEG Mtg., San Francisco: 1439-1442.
- Dewangan, P. and Grechka, V., 2003. Inversion of multicomponent, multiazimuthal, walkaway VSP
- data for stiffness tensor. Geophysics, 68: 1022-1031.
- Farra, V., 2001. Higher-order perturbation of the phase velocity and polarization of qP and qS
- waves in anisotropic media. Geophys. J. Internat., 147: 93-104.
- Gaiser, J.E., 1990. Transversely isotropic phase velocity analysis from slowness estimates. J.
- Geophys. Res., 95: 11241-11254.
- Grechka, V., Jorgensen, P. and Lopez, J.L., 2006. Anisotropy estimation from marine 3D VSP
- data. Offshore Technol. Conf., Houston: OTC17866.
- Grechka, V. and Mateeva, A., 2007. Inversion of P-wave VSP data for local anisotropy: Theory
- and case study. Geophysics, 72: D69-D79.
- Grechka, V., Mateeva, A., Gentry, C., Jorgensen, P. and Lopez, J.L., 2007. Estimation of seismic
- anisotropy from P-wave VSP data. The Leading Edge, 26: 756-759.
- Horne, S. and Leaney, $., 2000. Short note: Polarization and slowness component inversion for TI
- anisotropy. Geophys. Prosp., 48: 779-788.
- Hsu, K., Schoenberg, M. and Walsh, J., 1991. Anisotropy from polarization and moveout: A case
- study. Expanded Abstr., 61st Ann. Internat. SEG Mtg., Houston: 1526-1529.
- Jilek, P., Hornby, B. and Ray, A., 2003. Inversion of 3D VSP P-wave data for local anisotropy:
- P and SV SLOWNESS-POLARIZATION INVERSION 473
- A case study. Expanded Abstr., 73rd Ann. Internat. SEG Mtg., Dallas: 1322-1325.
- Miller, D.E. and Spencer, C., 1994. An exact inversion for anisotropic moduli from phase slowness
- data. J. Geophys. Res., 99: 21651-21657.
- Pevzner, R., Gurevich, B. and Urosevic, M., 2011. Estimation of azimuthal anisotropy from VSP
- data using multicomponent S-wave velocity analysis. Geophysics, 76: D1-D9.
- PSendik, I. and Gajewski, D., 1998. Polarization, phase velocity, and NMO velocity of qP-waves
- in arbitrary weakly anisotropic media. Geophysics, 63: 1754-1766.
- Rusmanugroho, H. and McMechan, G.A., 2012a. 3D 9C seismic modeling and inversion of
- Weyburn field data. Geophysics, 77: R161-R173.
- Rusmanugroho, H. and McMechan, G.A., 2012b. Sensitivity of estimated elastic moduli to
- completeness of wave type, measurement type, and illumination aperture at a receiver in
- multicomponent VSP data. Geophysics, 77: R1-R18.
- Tsvankin, I., 2012. Seismic signatures and analysis of reflection data in anisotropic media, 3rd Ed.
- SEG, Tulsa, OK.
- Tsvankin, 1. and Grechka, V., 2011. Seismology of azimuthally anisotropic media and seismic
- fracture characterization. SEG, Tulsa, OK.
- White, J.E., Martineau-Nicoletis, L. and Monash, C., 1983. Measured anisotropy in Pierre shale.
- Geophys. Prosp., 31: 709-725.
