Anisotropy pattern arising from application of a triaxial stress to a dry isotropic rock
MetadataShow full item record
Elastic wave velocities in rocks vary with stress due to the presence of discontinuities and microcracks within the rock. We analytically derive a model for seismic anisotropy caused by small triaxial stresses applied on a linearly isotropic elastic medium permeated by a distribution of cracks with random orientations. This model predicts ellipsoidal anisotropy and also expresses the ratios of Thomsen’s parameters ε/γ as a function of the compliance and Poisson’s ratios in the three orthogonal planes of symmetry. We apply this model to fully estimate the elasticity tensor from log or VSP data and infer P-wave anisotropy from S-wave anisotropy in an area where the anisotropy is known to result from anisotropy of stresses. Besides, this model could be used to differentiate stress-induced anisotropy from that caused by aligned fractures.
Showing items related by title, author, creator and subject.
Madadi, Mahyar; Pervukhina, Marina; Gurevich, Boris (2013)We propose an analytical model for seismic anisotropy caused by the application of an anisotropic stress to an isotropic dry rock. We first consider an isotropic, linearly elastic medium (porous or non-porous) permeated ...
Modeling shear wave splitting due to stress-induced anisotropy, with an application to Mount Asama Volcano, JapanShelley, A.; Savage, M.; Williams, C.; Aoki, Y.; Gurevich, Boris (2014)We use numerical modeling to investigate the proposed stress-based origin for changing anisotropy at Mount Asama Volcano, Japan. Stress-induced anisotropy occurs when deviatoric stress conditions are applied to rocks which ...
Estimating azimuthal stress-induced P-wave anisotropy from S-wave anisotropy using sonic log or vertical seismic profile dataCollet, O.; Gurevich, Boris; Duncan, G. (2015)Most sedimentary rocks are anisotropic, yet it is often difficult to accurately incorporate anisotropy into seismic workflows because analysis of anisotropy requires knowledge of a number of parameters that are difficult ...