Azimuthal Reflectivity And Quantitative Evaluation of Anisotropic Parameters From Seismic Data: a Feasibility Study

is the vector containing the x-, y-, and zcomponents of the displacement vector u and the vertical component of the stress tensor . A in equation (1) is the 6X6 elastic system matrix whose components are functions of the elastic stiffness coefficients (cij), density ( ), and xand y components of the slowness px and py. Finally, F in equation (1) is the source term. Now, let the eigenvectors of the elastic system matrix A be given by the matrix D, i.e., Summary We study the dependence of Pand converted-wave reflectivity with incidence angle and azimuth for azimuthally anisotropic elastic media. Computing Pand converted-wave reflection coefficients using exact formulation, and inverting them using their asymptotic representations, we find that the P-wave reflectivity alone does not provide robust estimates of anisotropy parameters. If, on the other hand, the P-wave reflectivity is analyzed in conjunction with the converted-wave reflectivity, it is possible to get robust estimates of many useful anisotropic parameters that can be directly linked with fracture orientation and fracture density when the observed anisotropy is due to oriented fractures. We, therefore, conclude that both Pand converted-wave data are necessary to get robust estimates of fracture parameters from surface seismic data. , 1 D D A (3)