JSON input specification

JSON specification for xpm input

Paragraph indent resembles the nesting levels in the JSON input file.

This file has been automatically generated from a machine-readable JSON schema.

image : object

Image properties.

• path : string
     Path to an 8-bit uncompressed image.

• size : int[3]
     Voxel count in 3 dimensions.

• resolution : real
     Side length of a voxel, m.

• phase : object

  • void : int
       Value for void voxels, must be 0.

  • solid : int
       Value for solid voxels.

macro : object

Macroscopic network properties.

• contact_angle : real
     Contact angle, deg.
     default : 0

• trans_multiplier : real
     Transmissibility multiplier.
     default : 1

darcy : array

Array of darcy properties per under-resolved image value.

• value : int
     Value of the underlying under-resolved phase.

• poro : real
     Porosity, frac.

• perm : real
     Permeability, mD.

• cap_press : array[2]
     Capillary pressure curves, Pa (one data table per flooding cycle).

• rel_perm : array[2]
     Relative permeability curves (array of two data tables per flooding cycle).

• rgb : int[3]
     Color in RGB format.

• file : string
     Path to an external JSON file that contains relevant darcy properties.

Acceptable data table format is [[x1, y1], [x2, y2], ...] or [x1, y1, x2, y2, ...] where x(i) < x(i+1).

solver : object

Linear solver properties.

• cache : object
     Caching of pressure solutions.

  • use : bool
       default : false

  • save : bool
       default : false

• decomposition : int[3]
     Volume decomposition in 3 dimensions. MPI processor count is the product of 3 components.

• tolerance : real
     The convergence tolerance.
     default : 1.00e-6

• max_iterations : int
     Maximum number of iterations.
     default : 100

• print_level : int
     Requests automatic printing of setup and solve information.
     0 : no printout
     1 : print setup information
     2 : print solve information
     3 : print both setup and solve information
     default : 0

• aggressive_number_of_levels : int
     Defines the number of levels of aggressive coarsening.
     default : 0

report : object

Reporting properties.

• display : string
     Display property of the 3D view.
     values : "pressure" | "saturation" | "permeability" | "phase" | "velem" | "decomposition"

• invasion_percolation : bool
     Simulate invasion percolation.
     default : false

• occupancy_images : bool
     Write 3D image files for different occupancies.
     default : false

• capillary_pressure_sw_step : real
     Sw step in capillary pressure curves.
     default : 0.05

• relative_permeability_sw_step : real
     Sw step in relative permeability curves.
     default : 0.075

Examples

Two-phase image

{
  "$schema": "https://raw.githubusercontent.com/dp-69/xpm/main/files/xpm.schema.json",
  "image": {
    "path": "EstailladesNano-v0s255_335x335x503_0p032um.raw",
    "size": [335, 335, 503],
    "resolution": 32.0e-9,
    "phase": {
      "void": 0,
      "solid": 255
    }  
  },
  "macro" : {
    "trans_multiplier": 1,
    "contact_angle" : 59
  },
  "solver": {
    "cache" : { "use" : true, "save" : true },
    "decomposition": [4, 3, 3],
    "tolerance": 1e-9,
    "max_iterations": 19    
  },
  "report" : {
    "invasion_percolation": true,
    "display" : "saturation",
    "occupancy_images": false,
    "capillary_pressure_sw_step": 0.075,
    "relative_permeability_sw_step": 0.1
  }
}