Reflection amplitudes of pre-stack seismic data are dependent upon changes of P- and S-wave velocities and densities (referred to as .rock properties.) across interfaces. It follows, then, that sensitivity analysis of AVO attributes to reservoir conditions is necessarily done through models that link reservoir conditions to rock properties.
A technique is presented to determine the elastic constants (moduli) and densities of the constituents of rocks by minimizing the difference between measured and modeled P- and S-wave velocities and density logs. The technique assumes that the elastic properties and densities of the individual constituents (sand, shale, gas and water for clastic, gas producing rocks) do not change in the interval being evaluated.