Once these strata or layers are identified, the distribution of channel
complexes versus overbank deposits within each strata represents
second order heterogeneities. The distribution of individual channels
within each channel complex constitutes third order heterogeneities.
Sequence stratigraphy allows such hierarchical classification of
heterogeneities down to the bed set or bed level. This genetic
hierarchy of heterogeneities within a given reservoir is best
modeled through a hierarchical procedure. A hierarchical object-based
procedure was applied to model the channel sand distribution in each
layer. The key geologic input parameters are (1) the proportion of
channel sand that could vary vertically and areally, (2) geometric
parameters defining the channel thicknesses, widths, and sinuosities,
and (3) well data. In this case, the layer proportions were assumed
constant, realistic channel geometries were considered, and no well
data were used to constrain the model. The second panel of
Figure shows a cross section through the channel and
overbank shale facies model.