Estimation of Thomsen's anisotropy parameter δ and ε using EO Gathers

Pavan Kumar Elapavuluri, John C. Bancroft

A measure of the different anisotropic parameters is essential in order to extend the seismic processing techniques to anisotropic media. The purpose of this study is to estimate the Thomsen's P-wave anisotropy parameters namely and , for transversely isotropic (TI) media. An inversion techniques based on the shifted hyperbola NMO equation is used for the estimation. Equivalent Offset (EO) gathers give a better estimate of the anisotropy parameters than conventional CMP/CDP gathers. This method was tested on the data collected over a synthetic model. It has been shown that can be estimated very accurately while estimation of is not as exact as . The anisotropic parameters of various formations of interest were estimated over the Blackfoot field in western Canada using this method.