Seismic modeling of the reservoir required a technique that could handle an Earth model that is both elastic and heterogeneous. This restricted the choice of method available to us.
Zoeppritz or reflectivity methods were not useful as they can only model homogeneous plane layers and cannot capture the effect of heterogeneities. Also finite difference or spectral methods were not useful as they are too computationally intensive for modeling a full multi-offset 3-D survey. This suggested a ray-based scattering approach, such as the first order Born approximation as described by Wu and Aki 1985. More detailed description of the modeling method and direct comparison with Zoeppritz method can be found in Rickett et al. (1996).