Patent ID: 8204726

Claim:
A multi-scale method for use in simulating multi-phase fluid flow in a subsurface reservoir comprising: (a) providing a simulation model for a subsurface reservoir that includes a fine-scale grid defining a plurality of fine-scale cells and a coarse-scale grid defining a plurality of coarse-scale cells that are aggregates of the fine-scale cells; (b) determining a coarse-scale pressure for each coarse-scale cell; (c) determining a coarse-scale velocity and a coarse-scale saturation for each coarse-scale cell responsive to the coarse-scale pressure; (d) defining saturation regions that correspond to each coarse-scale cell, the saturation regions being defined responsive to predetermined saturation properties that are associated with the coarse-scale velocity and the coarse-scale saturation for each coarse-scale cell; (e) determining a fine-scale saturation value for each saturation region; (f) assembling the saturation regions with each respective fine-scale saturation value to obtain a fine-scale saturation distribution; and (g) outputting a visual display responsive to the fine-scale saturation distribution.