Fluid volume consisting of two or more contacting phases

In most practical cases in Petroleum Industry it will be a 3-phase fluid (water, oil and gas).

The total fluid density of multiphase fluid is given by following equation:

(1)	$\begin{array}{l}\displaystyle \rho = \sum_\alpha s_\alpha \, \rho_\alpha\end{array}$

where

$\begin{array}{l}\rho_\alpha\end{array}$

Density of $\begin{array}{l}\alpha\end{array}$ -phase

$\begin{array}{l}s_\alpha\end{array}$

volumetric share of $\begin{array}{l}\alpha\end{array}$ -phase

Derivation

(2)	$\begin{array}{l}\displaystyle \rho = \frac{m}{V} = \frac{\sum_\alpha m_\alpha}{V} = \sum_\alpha \frac{m_\alpha}{V}= \sum_\alpha \frac{V_\alpha}{V} \cdot \frac{m_\alpha}{V_\alpha} = \sum_\alpha s_\alpha \, \rho_\alpha\end{array}$

Page tree

See also