Amplitudes e padrões de polarização de pulsos em meios anisotrópicos

Abstract

Extracting subsurface lithological information from seismic data has become a great challenge to seismic exploration, as the hypotheses of stratification made by isotropic layers has been insufficient to represent the behavior of elastic field in surveys with great offset between source and receiver, multicomponent geophones, three-dimensional Vertical Seismic Profile (VSP) measures and so forth. Due to this reason, a more realistic model of subsurface is demanded. As a result, the seismic prospecting starts to consider the anisotropic models of subsurface to characterize reservoirs, for example. This paper aims at showing formalism to model the scattering of pulses from incident plane waves in horizontal plain interfaces which separate anisotropic media. This scattering is obtained primarily through the explicit formulation of traction and deformation fields as a function of propagator, polarization and impedance matrices of media. After that, this formalism is used to obtain the reflection and transmission coefficients matrices through a horizontal plain interface to be, subsequently generalized to a scattering through multiple layers. Finally, the amplitude of an analytical pulse is inserted in the incident wave to calculate the scattering of the pulse through stratifications.