On the Problem of Elastic Anisotropy Estimation in the Rocks with Quasi Orthotropic Symmetry

Abstract

Abstract—The principles for estimating the degree of elastic anisotropy of the medium (the rocks) with transverse isotropic and orthorhombic symmetry are considered. Because of the structural heterogeneity, rocks cannot be considered as strictly having a single type of symmetry. With this fact taken into account, formulas are developed for estimating the elastic anisotropy of the rocks with quasi-orthotropic symmetry from the velocities of compressional and shear waves. The criteria for separating the media into weakly and strongly anisotropic are proposed. The developed parameters can be used for mass determinations of elastic anisotropy of rocks.