A comprehensive AVO analysis led to lithologic identification and reservoir characterization of the Xujiahe formation, Sichuan Basin. The AVO analysis includes assessment of the surface seismic dataset to investigate how well it meets the requirements for AVO inversion. Specifically, we examined the influence of the multiples that have remained in the data and the ambient noise on the AVO analysis. We compared the gathers from prestack time migration with synthetic records created at 13 well locations to check the presence and validity of AVO anomalies. Following the AVO inversion, we performed crossplot interpretation of the AVO attributes that include intercept and gradient, P- and S-wave reflectivities, pseudo-Poisson and P-wave reflectivity, P and G, and lamda-rho and mu-rho. From the AVO crossplots, we identified the top and bottom of a thick reservoir with high porosity. However, the AVO attributes failed to infer relatively thin reservoirs.
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