# MATERIAL_PROPERTY with permeability and porosity¶

Note that if a mesh format different than GRDECL is used, the porosity and permeability values will be taken from MATERIAL_PROPERTY. Therefore, in addition to the data input described in MATERIAL_PROPERTY, the user must enter the PERMEABILITY and POROSITY block:

MATERIAL_PROPERTY <material_name>
ID <material_id>
POROSITY [<constant_porosity>, DATASET <porosity_dataset>]
<PERMEABILITY BLOCK>
CHARACTERISTIC_CURVES <ch_curve_name>
ROCK_DENSITY <rock_density>
SOIL_COMPRESSIBILITY <soil_compress_coeff>
SOIL_COMPRESSIBILITY_FUNCTION <compress_function_type>
SOIL_REFERENCE_PRESSURE [<ref_press> or INITIAL_PRESSURE]
SPECIFIC_HEAT <spec_heat> or HEAT_CAPACITY <heat_cap>
THERMAL_CONDUCTIVITY_DRY <th_cond_dry>
THERMAL_CONDUCTIVITY_WET <th_cond_wet>
END


## PERMEABILITY¶

Note that permeabilities are specified in m2 , rather than milliDarcies, as used by Eclipse.

<PERMEABILITY BLOCK> depends on the type of permeability field to be used, as follows:

<PERMEABILITY BLOCK> for Isotropic and homogeneous permeability fields:

PERMEABILITY
ISOTROPIC: Turn off anisotropy.
PERM_ISO <iso_perm_value>: specifies a constant isotropic permeability value [m2]
END


<PERMEABILITY BLOCK> for anisotropy and homogeneous permeability fields:

PERMEABILITY
PERM_X <perm_x_value>: specifies a constant permeability value in x-direction [m2]
PERM_Y <perm_y_value>: specifies a constant permeability value in y-direction [m2]
PERM_Z <perm_z_value>: specifies a constant permeability value in z-direction [m2]
END


<PERMEABILITY BLOCK> for anisotropic and heterogeneous permeability fields:

In this case the permeabilities are taken from a ‘dataset’, a block of data which is normally loaded from a file:

PERMEABILITY
ANISOTROPIC or ISOTROPIC: specifies the type of permeability field
DATASET <dataset_name>: dataset where the permeability field is defined [m2]
END


In case of ANISOTROPIC permeability, three data sets must be present in the input deck, named <dataset_name>X, <dataset_name>Y and <dataset_name>Z respectively.

## POROSITY¶

This can be defined in two alternative ways:

• <constant_porosity>: assigning a constant value for all cells belonging to the material being defined.

• DATASET <porosity_dataset>: assigning porosity values cell-by-cell, where the values are provided in a DATASET defined in the input deck.

The example below illustrates a heterogeneous anisotropic case. Note that in addition to this information, the required datasets must have been loaded - see DATASET for details of how to do this:

MATERIAL_PROPERTY formation
ID 1
POROSITY DATASET Porosity
ROCK_DENSITY 2.350d3
SPECIFIC_HEAT 1.0d3
THERMAL_CONDUCTIVITY_DRY 1.541d0
THERMAL_CONDUCTIVITY_WET 1.541d0
CHARACTERISTIC_CURVES ch1
PERMEABILITY
ANISOTROPIC
DATASET perm
/
/


## DATASET¶

Specifies a data set to be associated with parameter sets in the model.

DATASET <dataset_name>
FILENAME <dataset_file_name>: specifies the external file name of the dataset
HDF5_DATASET_NAME <hdf5_dataset_name>: specifies the dataset name
END


See example below for a dataset defining the permeability in the x direction

DATASET permX
FILENAME perm_poro.h5
HDF5_DATASET_NAME PermeabilityX
END


Note such datasets must follow the conventions of an HDF5 file. Such datasets normally need to be prepared by external programs which link in the HDF5 libraries.