Reservoir characterization is essential for providing optimal recovery from heavy-oil fields. The process of reservoir characterization is demonstrated for a steam injection project at Pikes Peak heavy oil field near Lloydminster, Saskatchewan, Canada. Geologic, geophysical and reservoir engineering data are used to improve the interpretation of reservoir conditions. There is ambiguity in modeling any of these data. However, in modeling all data sets in “cooperative inversion,” ambiguity is decreased, thereby enhancing our knowledge of the reservoir. One of the main benefits of this oil-field modeling is that bypassed oil and steam fronts are effectively mapped.