Single-phase gas flow (subsonic)

Input(s)

$P_{d}$: Downstream Pressure $(\mathrm{psi})$

$P_{u}$: Upstream Pressure at Choke $(\mathrm{psi})$ k: Specific Heat Ratio (dimensionless) A: Cross Sectional Area of Choke (in. ${ }^{2}$ )

$\gamma_{g}$ : Gas Specific Gravity related to Air (dimensionless)

$T_{u}$: Upstream Temperature (R)

$C_{d}$ : Choke Discharge Coefficient (dimensionless)

Output(s)

$q_{s c}$: Gas Flow Rate $(\mathrm{Mscf} / \mathrm{D})$

Formula(s)

$$ q_{s c}=1248 * C_{d} * A * P_{u} *\left(\left(\left(\frac{k}{(k-1) * \gamma_{g} * T_{u}}\right) *\left(\left(\frac{P_{d}}{P_{u}}\right)^{\frac{2}{k}}-\left(\frac{P_{d}}{P_{u}}\right)^{\frac{k+1}{k}}\right)\right)^{0.5}\right) $$

Reference(s)

Boyun, G., William, C., \& Ali Ghalambor, G. (2007). Petroleum Production Engineering: A Computer-Assisted Approach, Page: 5/61.