Explicit Zonation

The explicit zonation option is best suited for simulations with a limited number of rock/soil types. The approach is to define rock/soil names and then associate those names with a spatial zone across the computational domain. Rock/soil names are generally unrestricted, but need to be less than 64 characters in length. Intrinsic properties of the defined rock/soil types will then be associated with the grid cells within the spatial zone on other input cards (e.g.,Hydraulic Properties Card, Mechanical Properties Card, Saturation Function Card, Aqueous Relative Permeability Card). Spatial zones are specified using ranges of indices in the three local grid directions.

The following key words have special meanings when used within a rock/soil name:

• skip conv is used to skip convergence checks on nodes with associated rock/soil types
• dp, dual porosity, or fractured in the rock/soil name indicate a dual porosity medium, which triggers the reading of both matrix and fracture properties

When explicitly declaring the rock/soil zonations, rock/soil names can be repeatedly applied to a grid cells or domain of grid cells, with only the last definition being applied.

Tip

Rock/soil zonations with overlapping domains will be assigned according to the last specification in the list of domains. To simplify the zonation of a problem with a dominant rock/soil type and isolated pockets or bands of another rock/soil type, the user should initially declare the dominant rock/soil type as covering the entire problem domain. With subsequent input lines, the user can overwrite the original rock/soil type for selected nodes with another rock/soil type. This layering approach is recommended and will often avoid leaving nodes of undeclared rock/soil types.

External Files

The external file option is similar to the explicit zonation option, but the association of define rock/soil types with grid cells is via the external file. The external files contain one integer for every grid cell, using conventional i, j, k ordering. The integer corresponds with one of the defined rock/soil types. A value of 0 is used to indicate that the grid cell is inactive. This option can be useful when the rock/soil zonation data are automatically generated (e.g., geologic visualization programs). In this case, the user must specify a rock/soil name for each zone with like material properties. Intrinsic properties of the defined rock/soil types will then be associated with the grid cells within the spatial zone on other input cards (e.g.,Hydraulic Properties Card, Mechanical Properties Card, Saturation Function Card, Aqueous Relative Permeability Card).

External File Sub-Options include:

• Formatted (ASCII) Files: Text files that can be read by conventional text readers
• Unformatted (Binary) Files: Files that must be created within the same operating system and an executable created with the same FORTRAN compiler as that used to compile and link the STOMP source code.

IJK Indexing

This option should be used when every grid cell is associated with a unique rock/soil type, as common with statistically generated rock/soil distributions. With IJK Indexing the concept of rock/soil types is abandoned for a system where the intrinsic properties of the geologic media are associated with the grid cell. The rock/soil type of a grid cell is extended to boundary surfaces adjacent to the grid cell (i.e., intrinsic properties of the geologic media on boundary surfaces are those of the rock/soil type property or IJK Indexing property descriptions for the node adjacent to the boundary surface). IJK Indexing Sub-Options include:

Info

If IJK Indexing is specified in the Rock/Soil Zonation Card then any of the existing following cards must also have the Rock/Soil Name identified as "IJK Indexing:"

Mechanical Properties Card, Hydraulic Properties Card, Saturation Function Card, Aqueous Relative Permeability Card, Gas Relative Permeability Card, Directional Aqueous Relative Permeability Card