Amount of fluid mass passing through a certain area per unit time:

\dot m_A = \frac{d m}{ d  t} \Big|_A = j_m \cdot A

where

SI unit	Metric unit	Oilfield units
kg /s	kg /s	lb/s

\dot m_A = \rho_A \cdot q_A

In case of Volatile Oil Reservoir the connection with surface flowrates will be:

\dot m_O = \rho_O \cdot q_O

\dot m_G = \rho_G \cdot q_G

\dot m_W = \rho_W \cdot q_W

See also