pc_map_to_pc_curve

pc_map_to_pc_curve(pc, im, seq=None, mode='drainage', pc_min=None, pc_max=None, fix_ends=True)

Converts a pc map into a capillary pressure curve

Parameters:

• pc (ndarray) – A numpy array with each voxel containing the capillary pressure at which it was invaded. -inf indicates voxels which are filled with non-wetting fluid at all pressures, and +inf indicates voxels that are filled by wetting fluid at all pressures. Values in the solid phase are masked by im so are ignored.

• im (ndarray) – A numpy array with True values indicating the void space and False elsewhere. This is necessary to define the total void volume of the domain when computing the saturation.

• seq (ndarray, optional) – A numpy array with each voxel containing the sequence at which it was invaded. This is required when analyzing results from invasion percolation since the pressures in pc do not correspond to the sequence in which they were filled.

• mode (str) – Indicates whether the invasion was a drainage or an imbibition process. Options are ‘drainage’ and ‘imbibition’.

• fix_ends (bool (default is True)) – A flag to control whether to adjust the endpoints of the curve or not. The default is True, which will put add a point at the beginning and end the curves corresponding to residual and trapped invading phase saturations. This makes the curves look better when plotted. Disabling this correction ensures that the (Pc, Snwp) data match the values in the displacement maps, which is useful for making animations for instance.

Returns:

results – A dataclass like object with the following attributes:

Attribute	Description
pc	The capillary pressure
snwp	The fraction of void space filled by non-wetting phase at each pressure in pc

Return type:

dataclass-like

Notes

To use this function with the results of porosimetry or ibip the sizes map must be converted to a capillary pressure map first. drainage and invasion both return capillary pressure maps which can be passed directly as pc.