A numerical geological model of a braided stream fluvial reservoir with an average net-to-gross ratio (proportion of channel sand) of 0.65 was constructed with no well or seismic conditioning data. The physical dimensions of the 200 million cell model are:

X | 5 km | 1000 x 5 m |

Y | 5 km | 1000 x 5 m |

Z | 100 m | 200 x 0.5 m |

High-resolution sequence stratigraphy, made possible by dense 3-D seismic and close-distance well logging data, reveals a reservoir framework composed of repetitive strata bounded by time-correlatable or chronostratigraphic surfaces. These strata often contain facies that contrast drastically in petrophysical properties such as permeability and porosity. It is necessary to treat these surfaces as first order heterogeneities for reservoir description and fluid flow modeling. In this modeling exercise, the 100 m vertical extent was modeled with three geological strata with 0.8, 0.4, and 0.6 net-to-gross ratios (proportion of channel sand) respectively. The top panel of Figure shows a cross section through one layer.

11/12/1997