A constant porosity of 15% and permeability of 0.01 md was assigned to the overbank shale deposits. Although the total porosity of the overbank shales was considered to be 15%, the effective porosity was considered to be 0%. Within the channel sands, porosity was assigned with sequential Gaussian simulation (SGS). The SGS algorithm constructs a stochastic porosity model constrained to a histogram of porosity, a model of spatial correlation, and well data. In this case, realistic input statistics were chosen on the basis of published North Sea reservoir examples. The histogram of porosity is shown on Figure . The third panel of Figure shows a cross section through the porosity model.
Finally, permeability was related to porosity through a scatterplot. Figures and give the histograms and porosity-permeability scatterplot.