Estimation of elastic anisotropy from three-component ultrasonic measurements using laser Doppler interferometry

Abstract

Ultrasonic measurements using laser Doppler interferometry (LDI) have been reported to provide robust estimates of elastic anisotropy of rock samples. In this approach, an ultrasonic wave is emitted by a piezo-electric source and detected by the LDI, which can be configured to measure three components of the particle velocity in a very small area (∼1 mm 2) of the sample. Repeating these measurements for a dense array of points on the sample's surface gives a distribution of traveltimes and polarisation fields on the surface. Anisotropy is then obtained by inverting these fields using analytical expressions or numerical algorithms for computing phase and group velocities. The existing impleme..