The cost and complexity of deep-water subsalt development wells is so great that a very limited spatial sampling of the target reservoir is achievable with well data. Thus, the quantitative use of seismic data becomes of paramount importance.
Poststack seismic amplitude inversion, and poststack seismic attribute analysis and modeling are frequently employed to perform quantitative prediction of reservoir properties from surface seismic data. Several authors have shown that both absolute and relative acoustic impedance (AAI and RAI, respectively) derived from poststack seismic amplitude inversion can be useful for quantitative estimates of summary reservoir properties such as average porosity, net-to-gross, and others. This includes suprasalt and minibasin clastic reservoirs typically encountered in the Middle and Lower Tertiary plays in the deep-water Gulf of Mexico (several of which are also encountered subsalt), where depth to target can exceed 9000 m and highest frequencies at target are often rather low (20–25 Hz) (Bogan et al., 2003, Vernik et al., 2002).