A Nonparametric Estimation Method for Acoustic Dispersion and Attenuation Analysis

Abstract

Dispersion and attenuation analysis can be used to determine formation anisotropy induced by fractures, or stresses. In this paper, we propose a nonparametric spectrum estimation method to get phase dispersion characteristics and attenuation coefficient. By designing an appropriate vector filter, phase velocity, attenuation coefficient and amplitude can be inverted from the waveform recorded by the receiver array. Performance analysis of this algorithm is compared with EPM and FBMP, based on the analysis, the proposed method is capable of achieving high resolution and precision as the parametric spectrum estimation methods in the meantime, it also keeps high stability as the other nonparametric spectrum estimation methods. At last, applications to synthetic waveforms modeled using finite difference method show its efficiency.