Grid Card Options (HYDT-KE)

All STOMP-HYDT-KE grids are structured and orthogonal to nearly orthogonal, with hexahedral grid cells. A number of different ways of specifying grids are available in STOMP-HYDT-KE: Cartesian, Cylindrical, Boundary Fitted (or Curvilinear), Generic Eclipse, EarthVision Sampled, and Element and Vertices. STOMP also accommodates grids with displaced adjacent grid cells.

Cartesian

For the Cartesian coordinate system, the terms west, south, and bottom refer to the negative x-, y-, and z-directions, respectively, and the terms east, north, and top refer to the positive x-, y-, and z-directions, respectively. Negative dimensional values are not recognized, and axes are defined positive toward increasing node numbers.

(Non-uniform) Cartesian

A “right-handed” system with the longitudinal axis (z-direction) aligned with the negative gravitational vector and non-uniform grid spacing. In this case, the locations of the cell edges are specified and there is one more value than the number of grid cells in the corresponding direction.

Uniform Cartesian

A “right-handed” system with the longitudinal axis (z-direction) aligned with the negative gravitational vector and uniform grid spacing. In this case, the grid cell dimension in each direction is specified.

Tilted Cartesian

The entire domain is tilted with respect to the gravitational vector by a specified angle in each of the x-z and y-z planes. The grid spacing is specified as for the non-uniform cartesian case.

Cylindrical

For the cylindrical coordinate system, the terms west, south, and bottom refer to the negative r-, θ-, and z-directions, respectively, and the terms east, north, and top refer to the positive r-, θ-, and z-directions, respectively. Negative dimensional values are not recognized, and axes are defined positive toward increasing node numbers.

(Non-uniform) Cylindrical

The longitudinal axis (z-direction) is aligned with the negative gravitational vector and the radial (r–direction) and azimuthal (Θ-direction) axes are constrained to a horizontal plane. In this case, the locations of the cell edges are specified and there is one more value than the number of grid cells in the corresponding direction

Uniform Cylindrical

The longitudinal axis (z-direction) is aligned with the negative gravitational vector and the radial (r–direction) and azimuthal (Θ-direction) axes are constrained to a horizontal plane. In this case, the grid cell dimension in each direction is specified.

Boundary Fitted (or Curvilinear)

This format allows for curvilinear boundaries and requires the vertices of each grid cell to be specified via an external grid file. This option assumes that adjacent grid cells have co-located vertices, requiring only ((nx+1)*(ny+1)*(nz+1)) vertex inputs. The number of grid cells in x, y and z, the filename, and the units are specified in the Grid Card.

Generic Eclipse

This option reads a generic eclipse keyword (.grdecl) file, typically exported from Petrel™. This option allows for curvilinear boundaries. The number of grid cells in x, y and z, the filename, and the units are specified in the Grid Card. The number of grid cells specified in the Grid Card must match what is specified in the generic eclipse file. The user also must specify a minimum z-direction spacing to avoid overlapping layers and negative cell volumes.

Earthvision Sampled Input

This option reads a file generated from data exported from the EarthVision® geologic modeling software package. This option allows for curvilinear boundaries. The number of grid cells in x, y and z, the filename, and the units are specified in the Grid Card.

Element and Vertices

This option requires the specification of eight vertices for every node, (i.e., (nx*ny*nz)*8) via an external grid file. The number of nodes in x, y and z, the filename and the units are specified in the Grid Card.