Semblance-Based Anisotropy-Parameter Estimation of qP-Waves in Layered VTI Media Using Rational Interpolation

摘要

Nonhyperbolic moveout observed in common-midpoint gathers is often ascribed to the presence of seismic anisotropy in the subsurface. Such moveout is regularly used to get estimates of the underlying anisotropy parameters. The tau-p domain is the natural domain for anisotropy-parameter estimation in horizontally layered media (Van der Baan and Kendall, Geophysics, 2002 and 2003). The t-x domain is on the other hand the preferred domain for interpretation. The need to transform data to the tau-p domain or to pick traveltimes in the t-x domain is a practical disadvantage. Semblance-based approaches are significantly faster and probably more robust than manual picking of traveltimes. In this paper we combine the tau-p domain inversion technique of Van der Baan and Kendall (Geophysics, 2002) with the rational interpolation method of Douma and Calvert (Geophysics, 2006) to create a highly accurate semblance-based approach in the t-x domain for anisotropy-parameter estimation using P-waves in layered VTI media.