Structured flow-based gridding and upscaling for modeling subsurface flow

The combined use of flow-based grid generation and equivalent property calculation offers an effective means for generating subsurface flow simulation models from highly detailed geological descriptions. In this paper, several structured grid generation procedures, specifically a streamline-based method, a Jacobian-based elliptic grid generation approach, and an optimization technique, are investigated for this purpose. The ability of the more advanced methods to resolve both flow information and geological features is illustrated. In addition, both (local) permeability and (global) transmissibility upscaling methods are implemented in conjunction with the gridding approaches. The benefits of structured flow-based grids over uniform Cartesian grids are demonstrated for several three-dimensional cases. It is shown that these grids are most effective when a limited number of features dominate the flow. In addition, consistent with earlier work, global transmissibility upscaling is found to be preferable to permeability upscaling for highly heterogeneous systems.