Annular Flow Flow Rate

Flow rate in an annular flow regime is the volumetric or mass rate at which the gas and liquid phases are transported through the pipe.  The flow rate is generally divided into two components:

Gas Flow Rate (Q_g )  -  The volumetric flow rate of the gas phase flowing through the central core.
Liquid Flow Rate (Q_l )  -  The volumetric flow rate of the liquid phase forming the annular film along the pipe wall.

 

Annular Flow Flow Rate Formula
\( Q \;=\;  \dfrac{  (D_h^2 - D_p^2) \cdot AV }{ 24.51 } \)
Symbol	English	Metric
\( Q \) = Flow Rate	\(gpm\)	-
\( D_h \) = Hole Diameter	\(in\)	-
\( D_p \) = Drillstring Diameter	\(in\)	-
\( AV \) = Annular Velocity	\(ft \;/\; min\)	-