Total produced or injected flowrate of all fluids across the well-reservoir contact with the volumes measured at the sandface temperature and pressure conditions.

Usually abbreviated as $\begin{array}{l}q_t\end{array}$ or $\begin{array}{l}qB\end{array}$ .

(1)	$\begin{array}{l}\displaystyle q_t = B_w \, q_W + (B_o - R_v \, B_g) \, q_O + (B_g - R_s \, B_o) \, q_G\end{array}$

where

$\begin{array}{l}q_W, \, q_O, \, q_G\end{array}$	water, crude oil and natural gas surface flowrates
$\begin{array}{l}B_w, \, B_o, \, B_g\end{array}$	formation volume factors between separator and sandface pressure/temperature conditions
$\begin{array}{l}R_s, \, R_v\end{array}$	Solution GOR and Vaporized oil ratio at sandface pressure/temperature conditions

It simplifies for the Black Oil model to:

(2)	$\begin{array}{l}\displaystyle q_t = B_w \, q_W + B_o \, q_O + (B_g - R_s B_o) \, q_G\end{array}$

and simplifies further down to production from undersaturated reservoir as:

(3)	$\begin{array}{l}\displaystyle q_t = B_w \, q_W + B_o \, q_O\end{array}$

and even simpler for single-phase fluid with surface flow rate $\begin{array}{l}q\end{array}$ and formation volume factor B:

(4)	$\begin{array}{l}\displaystyle q_t = q \cdot B\end{array}$

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See also