To capture the expected range of rock properties and hence the expected range of seismic responses, for all
candidate lithology-fluid combinations over the depth range of interest, stochastic forward modelling was performed.
Gassmann substitution was an integral part of the modelling.Gas saturations used for modelling were 0% (brine case)
and 75+-5% (high saturation gas case). A low saturation gas was not considered in the final analysis due to the poor
discrimination from high saturation gas and a low geological risk for the presence of low saturation gas. For this study
10,000 forward models were produced for every depth step of 4 m. The parameters for each model were determined by the Monte Carlo sampling of the multidimensional rock physics model. The rock physics model is comprised of the
trends that are displayed in the four separate cross plots,however they should not be sampled from one trend at a
time because they are, in fact, coupled; they need to be thought of as one space and a single sample drawn from
this multidimensional space to get the correct distribution of properties.