Estimating anisotropy from borehole acoustic measurements
Abstract:
Measuring the velocity anisotropy of rock in a borehole is complicated since the measurement can only be done along the direction of the borehole. However, since the propagation velocity is determined by the direction of particle motion, it is possible to use shear waves to measure anisotropy of the rock. The presentation will cover the basis of wave propagation around a borehole and in particular shear waves and interface waves that are used in the measurement. Two methods are used to extract the amount and direction of anisotropy based on either inversion or FFT fitting of the data. The data is collected using a crossed dipole measurement tool and Alford rotation is used to handle the shear-wave splitting present in the anisotropic formation.
Applied Mathematics Seminar