Effect of stress on reflection and refraction of plane wave at the interface between fluid and stressed rock

Reflection and refraction of plane wave through an interface between fluid and rock with elastic deformations on the basis of the acoustoelastic theory are considered. The effects of stress on the anisotropy and energy reflection and transmission coefficients are investigated. The incident wave plane can coincide with or deviate from planes of material symmetry. Elastic deformations are assumed to be locally homogeneous and to satisfy static boundary conditions. Numerical computations are carried out and comparisons are made with the results predicted in the presence and absence of initial stress. The changes in phase velocity, group velocity, and energy reflection and refraction coefficients due to the presence of stress are displayed graphically and discussed. The results show that the effect of stress depends on its magnitude, direction and form (uniaxial and biaxial).

► We study wave propagation through a plane interface between fluid and rock with stress. ► Influence of stress on velocity, reflection and refraction coefficients are investigated. ► Critical angles become small with the increase of stress and energy redistribution is changed. ► Difference of the energy coefficients of the quasishear waves becomes big for biaxial stress.