Patent Document ID: 7546229
Application ID: 10995764
Patent Flag: 1

Claim One:
1. A multi-scale method for use in modeling fluid flow in a subsurface reservoir comprising on a processor: (a) creating a fine grid of the subsurface reservoir defining a plurality of fine cells and having a permeability field associated with the fine cells; (b) creating a coarse grid defining a plurality of coarse cells having interfaces between the coarse cells, the coarse cells being aggregates of the fine cells; (c) creating a dual coarse grid defining a plurality of dual coarse control volumes, the dual coarse control volumes being aggregates of the fine cells and having boundaries bounding the dual coarse control volumes; (d) calculating dual basis functions on the dual coarse control volumes by solving local elliptic or parabolic problems; (e) extracting fluxes across the interfaces of the coarse cells from the dual basis functions; (f) assembling the fluxes to calculate effective transmissibilities between coarse cells; (g) calculating fluid pressure in the coarse cells using a finite volume method and utilizing the effective transmissibilities between coarse cells; and (h) computing a fine-scale fluid velocity field utilizing the fluid pressure calculated in the coarse cells for use as a variable in modeling fluid flow in the subsurface reservoir with a subsurface reservoir simulator.