A numerical study of measured petrophysical properties was used to develop and demonstrate a workflow for monitoring sequestration in a subsurface reservoir. Amplitude versus offset (AVO) attributes can be sensitive discriminators for presence. The sensitivity of AVO attributes to saturation increased when an upscaling scheme that propagated the effects of small-scale heterogeneities was used. A global sensitivity analysis was then performed to study the importance of various rock properties that would be used as inputs in reservoir characterization. An extensive rock properties database for a carbonate reservoir containing natural variability was used. The various rock properties were ranked by their importance to the quality of the remote characterization. Defining and using the intrinsic correlations among petrophysical properties were essential to evaluating whether a particular reservoir was amenable (sensitive) to this AVO characterization method.