A property characterising agility of the fluid \alpha-phase under pressure gradient with account of reservoir permeability and dynamic fluid viscosity:
| (1) | M_\alpha(s) = \frac{k_\alpha}{\mu_\alpha} = k_{air} \cdot \frac{k_{r \alpha}}{\mu_\alpha} |
where
\displaystyle k_\alpha(s) | formation permeability to fluid \alpha-phase |
|---|---|
\displaystyle \mu_\alpha | dynamic viscosity of fluid \alpha-phase |
\displaystyle k_{air} | absolute permeability to air |
\displaystyle k_{r\alpha}(s) | relative formation permeability to fluid \alpha-phase |
\displaystyle M_{r\alpha}(s) = \frac{k_{r \alpha}}{\mu_\alpha} | relative phase mobility |
s | reservoir saturation \{ s_w, \, s_o, \, s_g \} |
In most practical case of a 3-phase fluid model this will be:
\displaystyle M_o = \frac{k_o}{\mu_o} | oil mobility |
\displaystyle M_g = \frac{k_g}{\mu_g} | gas mobility |
\displaystyle M_w = \frac{k_w}{\mu_w} | water mobility |