Global scale-up of reservoir model permeability with local grid refinement

This paper presents a new method for absolute permeability scale-up. The method is referred to as global scale-up because it attempts to preserve the variance and the spatial correlation within an entire permeability field. It focuses on the spatial connections within a global permeability field. Conventional methods, referred to as local scale-up, concentrate on local areas and can lead to loss of important structural information. obal approach scales up a field by selecting a minimum small variance of permeability and then finding permeability volume elements within which the variance is below the minimum. The global scale-up procedure preserves more of the statistical and structural information within the permeability field than local scale-up methods. A one-dimensional permeability transect from the Page Sandstone, an eolian deposit in northern Arizona, is used to illustrate the concepts. thod has been implemented in a three-dimensional algorithm that uses a moving window technique to detect boundaries of large permeability variance and then constructs a coarse-scale grid. The gridding method produces locally refined Cartesian grids. Permeability variability and tracer flood simulation data on three two-dimensional examples and one three-dimensional example show that the method preserves not only the geologic structural information but also the tracer flow behavior in the scaled-up model better than locally scaled-up models.