A property characterizing agility of the fluid under pressure gradient with account of reservoir permeability and dynamic fluid viscosity:
(1) | M = \frac{k}{\mu} |
where
k | formation permeability to fluid |
---|---|
\mu | dynamic viscosity of fluid |
In multiphase flow the concept of fluid mobility is not well-defined as phases may flow quite independently from each other and have different dynamic fluid parameters (pressure and velocity).
But for relatively homogeneous multi-phase flow (phases may move at different velocities but occupy the same reservoir space and have the same pressure) the multi-phase mobility may be defined by Perrine model:
(2) | \left<\frac{k}{\mu} \right> = k_{air} \left[ \frac{k_{rw}}{\mu_w} + \left( 1 + \frac{R_s \, B_g}{B_o} \right) \cdot \frac{k_{ro}}{\mu_o} + \left( 1 + \frac{R_v \, B_o}{B_g} \right) \cdot \frac{k_{rg}}{\mu_g} \right] |
and for the case of 2-phase Oil + Water fluid model (when Perrine model makes the most practical sense):
(3) | \left<\frac{k}{\mu} \right> = k_{air} \left[ \frac{k_{rw}}{\mu_w} + \frac{k_{ro}}{\mu_o} \right] |
See also
Physics / Fluid Dynamics / Percolation
Petroleum Industry / Upstream / Subsurface E&P Disciplines / Reservoir Flow Simulation
[ Field Study & Modelling ] [ Phase mobilities ] [ Relative Phase mobilities ]