The effect of stresses on the sound velocity in rocks: Theory of Acoustoelasticity and Experimental Measurements

Abstract

The theory of acoustoelasticity provides direct link between the change of elastic wave velocities and residual stresses in solids. The general theory of acoustoelasticity is reviewed. A number of experimental measurements of the effect of stresses on the sound velocities in various types of rocks are compiled and compared to the acoustoelastic theory. The theory of acoustoelasticity agrees within 1% of error with experiments for stress levels that are representative for in-situ reservior conditions. With the measurements of Nur and Simmons, acoustoelastic theory is found to agree with Sayers's microcrack model within 2% of error, much smaller than experimental error which was 10%. We may safely conclude that the theory of acoustoelasticity is a macroscopic version of the microcrack model and applicable to in-situ rocks.