SIMULATION
  SIMULATION_TYPE SUBSURFACE
  PROCESS_MODELS
    SUBSURFACE_FLOW flow
      MODE GENERAL
    /
  /
END

SUBSURFACE

GRID
  TYPE structured
  NXYZ 20 1 1
  DXYZ
   2.0d0
   1.0d0
   1.0d0
  END
END

REGION all
  COORDINATES
    0.0d0 0.0d0 0.0d0
    40.0d0 1.0d0 1.0d0
  /
END

REGION left_end
  FACE WEST
  COORDINATES
    0.d0 0.d0 0.d0
    0.d0 1.0d0 1.0d0
  /
END

REGION right_end
  FACE EAST
  COORDINATES
    40.0d0 0.d0 0.d0
    40.0d0 1.0d0 1.0d0
  /
END

REGION left_grid_cell
  COORDINATE 1.0d0 0.5d0 0.5d0 
END

MATERIAL_PROPERTY beam
  ID 1
  POROSITY 0.50
  TORTUOSITY 1.d0
  ROCK_DENSITY 2.8E3
  HEAT_CAPACITY 100.
  THERMAL_CONDUCTIVITY_DRY 1 W/m-C
  THERMAL_CONDUCTIVITY_WET 1 W/m-C
  CHARACTERISTIC_CURVES cc1
  PERMEABILITY
    PERM_X 1.d-15
    PERM_Y 1.d-15
    PERM_Z 1.d-15
  /
END

CHARACTERISTIC_CURVES cc1
  SATURATION_FUNCTION VAN_GENUCHTEN
    LIQUID_RESIDUAL_SATURATION 0.5d-1
    M 0.75
    ALPHA 1.d-3
  /
  PERMEABILITY_FUNCTION MUALEM
    LIQUID_RESIDUAL_SATURATION 0.05d0
    M 0.5d0
  /
  PERMEABILITY_FUNCTION MUALEM_VG_GAS
    LIQUID_RESIDUAL_SATURATION 0.05d0
    GAS_RESIDUAL_SATURATION 0.1d0
    M 0.5d0
  /
END

STRATA
  REGION all
  MATERIAL beam
END

EOS GAS
 VISCOSITY CONSTANT 1.0d-5 Pa-s
END

FLUID_PROPERTY
  DIFFUSION_COEFFICIENT 1.d-9
END

TIME
  FINAL_TIME 20 yr
  INITIAL_TIMESTEP_SIZE 1.d-4 day
  MAXIMUM_TIMESTEP_SIZE 0.01d0 yr at 0.d0 yr
END

OBSERVATION
  REGION left_grid_cell
END

OUTPUT
  SNAPSHOT_FILE
    NO_PRINT_INITIAL
    #NO_PRINT_FINAL
    FORMAT HDF5
  /
END

FLOW_CONDITION initial
  TYPE
    TEMPERATURE dirichlet
    MOLE_FRACTION dirichlet
    GAS_PRESSURE dirichlet
  /
  TEMPERATURE 25.d0 C
  MOLE_FRACTION 0.98
  GAS_PRESSURE 1.0d5 Pa
END

FLOW_CONDITION left_end
  TYPE
    TEMPERATURE dirichlet
    LIQUID_FLUX neumann
    GAS_FLUX neumann
  /
  TEMPERATURE 25.d0 C
  LIQUID_FLUX 0.d0 m/s
  # 0.17/((n/V)*R*T) = 0.17/(153.17*8.314*298.15)
  GAS_FLUX 4.475d-7 m/s
END

FLOW_CONDITION right_end
  TYPE
    TEMPERATURE dirichlet
    MOLE_FRACTION dirichlet
    GAS_PRESSURE dirichlet
  /
  TEMPERATURE 25.d0 C
  MOLE_FRACTION 0.98
  GAS_PRESSURE 1.0d5 Pa
END

INITIAL_CONDITION initial
  REGION all
  FLOW_CONDITION initial
END

BOUNDARY_CONDITION left_end
  REGION left_end
  FLOW_CONDITION left_end
END

BOUNDARY_CONDITION right_end
  FLOW_CONDITION right_end
  REGION right_end
END

END_SUBSURFACE