K	permeability
krg	gas relative permeability
kro	oil relative permeability
krow	oil relative permeability in oil–water flow
krw	water relative permeability
krog	equivalent two-phase (oil–gas) oil relative permeability in three-phase flow
$k_{row}^0$	oil relative permeability at connate water saturation
$k_{rog}^{\mathrm{*}}$	equivalent two-phase (oil–gas) oil relative permeability in three-phase flow
$k_{row}^{\mathrm{*}}$	equivalent two-phase (oil–water) oil relative permeability in three-phase flow
$k_{rN}^{Dr}$	drainage non-wetting-phase relative permeability
$k_{rN}^{Im}$	imbibition non-wetting-phase relative permeability
$k_{rN}^{Exp}$	experimental non-wetting-phase relative permeability
$k_{rw}^{\mathrm{*}}$	normalized relative permeability to water
$k_{rwi}^{\mathrm{*}}$	normalized imbibition relative permeability to water
$k_{rwd}^{\mathrm{*}}$	normalized drainage relative permeability to water
$k_{rw,p}^{\mathrm{*}}$	normalized relative permeability to water when saturation reversal occurs
$k_{rwd,p}^{\mathrm{*}}$	normalized drainage relative permeability to water when saturation reversal occurs
$k_{rwi,p}^{\mathrm{*}}$	normalized imbibition relative permeability to water when saturation reversal occurs
$k_{ro}^{\mathrm{*}}$	normalized relative permeability to water
$k_{roi}^{\mathrm{*}}$	normalized imbibition relative permeability to oil
$k_{rid}^{\mathrm{*}}$	normalized drainage relative permeability to oil
$k_{ro,p}^{*}$	normalized relative permeability to oil when saturation reversal occurs
$k_{rod,p}^{*}$	normalized drainage relative permeability to oil when saturation reversal occurs
$k_{roi,p}^{*}$	normalized imbibition relative permeability to oil when saturation reversal occurs
krwi[j]	imbibition relative permeability to water when saturation reversal occurs
$k_{rwi}^0\left[j\right]$	imbibition relative permeability to water at zero point when saturation reversal occurs
$k_{rwi}^1\left[j\right]$	imbibition relative permeability to water associated with bounding scanning curves of first reversal at Sw = 1 point when saturation reversal occurs
$k_{rwi}^t\left[j\right]$	imbibition relative permeability to water at threshold when saturation reversal occurs
kroi[j]	imbibition relative permeability to oil when saturation reversal occurs
$k_{roi}^0\left[j\right]$	imbibition relative permeability to oil at zero point when saturation reversal occurs
$k_{roi}^1\left[j\right]$	imbibition relative permeability to water associated with bounding scanning curves of first reversal at So =1 point when saturation reversal occurs
$k_{roi}^t\left[j\right]$	imbibition relative permeability to oil at threshold when saturation reversal occurs
$S_{Nr}^{max}$	maximum non-wetting residual saturation
$S_N^{max}$	the non-wetting-phase saturation
SNr	residual or trapped non-wetting saturation
$S_N^{Hyst}$	maximum historical non-wetting saturation
$S_{Nr}^{Norm}$	normalized non-wetting-phase saturation
Snwr	residual non-wetting-phase saturation trapped after complete imbibition of wetting phase
Snwi	historical maximum non-wetting-phase saturation reached before the change of process from drainage to imbibition, fraction of pore space
Snwf	“free” or continuous non-wetting-phase saturation, fraction of pore space
Snw	total non-wetting-phase saturation present independent of direction of saturation change, fraction of pore space
$S_w^{*}$	normalized water saturation, fraction
$S_{w,p}^{*}$	normalized water saturation, fraction when saturation reversal occurs
Sg	gas saturation
Sgc	critical gas saturation
So	oil saturation
$S_g^{og}$	equivalent two-phase (oil–gas) gas saturation in three-phase flow
Sor	the residual oil saturation in three-phase flow
$S_w^{ow}$	equivalent two-phase (oil–water) water saturation in three-phase flow
Sw	water saturation
Swc	connate water saturation
Sg	normalized gas saturation
So	normalized oil saturation
Sw	normalized water saturation
Sof	flowing oil saturation
Sot	ultimate trapped oil saturation
Soi	initial oil saturation
α	initial slope of IR curve in new trapping model
β	curvature of the IR curve in new trapping model
C	Land trapping coefficient