# SWSFN¶

The SWSFN keyword is followed by a table with three columns, in which the first is the water saturation ($$S_w$$), the second is the water relative permeability with respect to the solvent ($$K_{rws}$$), and the third is the capillary pressure between solvent and water ($$P_{csw}$$). The table must be terminated by a / or END. The SWSFN table is used only for the COMP3 mode and if the composition-dependent saturation functions option COMP_DEP_SFNS has been switched on. If COMP_DEP_SFNS is active and SWSFN is not found in the input, the code will assume that the relative permeability and the capillary pressure of the water/solvent system are identical to those for the gas/water system, and the values of SWFN will be used. An example of the table is shown below:

SWSFN
0.2 0 3.1026
0.25 0.0 1.3120
1.0 1.0 0.0
/

The first saturation entry in the table is the water connate saturation, $$S_{wco}$$ ($$0.2$$ in this example).

The largest water saturation value for which the water relative permeability is zero is the water residual saturation, $$S_{wcr}$$ ($$0.25$$ in this example). The last water saturation entry is the maximum water saturation, $$S_{w,\mbox{max}}$$ (usually $$1$$ as in the example above). $$S_w$$ must increase monotonically. $$K_{rws}$$ can be constant or increase as $$S_w$$ increases. $$P_{csw}$$ can be constant or decrease as $$S_w$$ increases. Note that the end points of SWSFN and SWFN must be the same for the same SATNUM value, that is the same connate and maximum water saturations, for which the relative permeability and capillary pressure values must coincide.