Difference between revisions of "Mobility Ratio"

Revision as of 14:21, 25 March 2022

Mobility Ratio determines the relative rate of one fluid to another (etc. water to oil).

M \le 1

oil is dominant flowing phase, stable flow.

M > 1

water preferentially flows in the reservoir, unstable flow, fingering.

M = \frac{k_w/ \mu_w}{k_o/ \mu_o}=\frac{k_{rw}/ \mu_w}{k_{ro}/ \mu_o}=\frac{q_w B_w}{q_o B_o}

where

B_o

= oil formation volume factor, m3/m3

B_w

= water formation volume factor, m3/m3

k_{rw}

= relative water phase permeability, function of the phase saturation, fraction

k_o

= oil phase permeability, function of the phase saturation, fraction

k_o

= relative oil phase permeability, function of the phase saturation, mD

k_w

= water phase permeability, function of the phase saturation, mD

M = mobility ratio, fraction :<math> \mu_o

= oil viscosity, cP

\mu_w

= water viscosity, cP

q_o

= oil rate, cc/sec

q_w

= water rate, cc/sec

Dimensionless injected pore volume:

W_{iD} = \frac{W_i * B_{wi}}{PV} = \frac{W_i * B_{wi}}{A * h * \phi}

Injected movable pore volume:

MOPV_{inj} = \frac{W_i * B_{wi}}{MOPV} = \frac{W_i * B_{wi}}{A * h * \phi *(1-S_{wc}-S_{orw})}

where

S_{wc}

= Connate water saturation, fraction

S_{orw}

= Residual oil saturation to water, fraction

↑ Wolcott, Don (2009). Applied Waterflood Field Development. Houston: Energy Tribune Publishing Inc.

@@ Line 10: / Line 10: @@
 :<math> M = \frac{k_w/ \mu_w}{k_o/ \mu_o}=\frac{k_{rw}/ \mu_w}{k_{ro}/ \mu_o}=\frac{q_w B_w}{q_o B_o}</math>
-where<ref name=DW/>
+where
 :<math> B_o </math> = oil formation volume factor, m3/m3
@@ Line 24: / Line 24: @@
 :<math> q_w </math> = water rate, cc/sec
-===Related definitions===
+==Example<ref name=DW/>==
 Dimensionless injected pore volume:
 :<math> W_{iD} = \frac{W_i * B_{wi}}{PV} = \frac{W_i * B_{wi}}{A * h * \phi}</math>