Prediction of sweet spots in tight sandstone reservoirs based on anisotropic frequency-dependent AVO inversion

Abstract The frequency-dependent amplitude-versus-offset (FAVO) method has become a practical for fluid detection in sand reservoirs. At present, most FAVO inversions are based on the assumption that reservoirs isotropy, but application effect is not satisfactory fractured Hence, we analyse frequency variation characteristics of anisotropy parameters tight sandstone new petrophysical model, and propose stepwise anisotropic inversion to extract attributes from prestack seismic field data. First, combine improved Brie's law with fine-fracture model velocities Thomsen at different gas saturations fracture densities. Then, derive an algorithm Rüger's approximation formula obtain dispersions parameters. Finally, combines spectral decomposition apply it Xinchang area. We use P-wave velocity dispersion parameter ? optimise favourable areas. Numerical analysis results show sensitive density, which can be used prediction In contrast, saturation detection. data second member Xujiahe Group, consistent logging interpretation results.