# Reservoir flow for gas flow in a formation

## Input(s)

\(n\): The Performance Exponent (dimensionless)

\(\bar{p}\): The Mean Formation Pressure in the Drainage System of Well (psi)

\(P_{w f}\): Bottomhole Flowing Pressure (psi)

C: Performance Coefficient, a Function of Mean Pressure Level (bbl/d psi)

## Output(s)

\(W\): Flow Rate \((\mathrm{bbl} / \mathrm{d})\)

## Formula(s)

\[
\mathrm{W}=\mathrm{C}\left(\overline{\mathrm{p}}^{2}-\mathrm{p}_{\mathrm{wf}}^{2}\right)^{\mathrm{n}}
\]

## Reference(s)

Ramey Jr, H. J. (1981). Reservoir Engineering Assessment of Geothermal Systems. Department of Petroleum Engineering, Stanford University. Page: 8.8.