Análise dos Resultados de Anisotropia Obtidos com Perfil Sônico confrontados com com registros de Imagem Acústica, Resistiva e VSP em Rochas Carbonáticas

Abstract

The paper intends to present the results obtained with sonic tool data in order to characterize the elastic anisotropy of aptian formations in two wells located at Santos Basin. Several borehole logging tools - sonic logs , acoustic and electric image logs, VSP walkaround and walkaway – had been their results compared each other and with the seismic surface data results. The recent improvements introduced in acoustic logging tools had allowed the acquisition of several elastic constants and Thomsen γ and e parameters opening the possibility to characterize 3D anisotropy. The results were compared with the VSP walkaway and walkaround anisotropy measurements. The major agreement of results were observed between the acquisitions made with similar wavelength: borehole seismic and seismic surface on one side; sonic tools and acoustic and electric image logs on the other side, showing that the resolution of the method is a determining factor in the measurement. The Stoneley wave analysis enabled to identify open fractures in the reservoir. Results were compared with azimuthal anisotropy data obtained from the crossed dipole acquisition and acoustic and electrical image logs data showing reasonable correlation.