Flow coefficient during drawdown

Input(s)

$p_{w f}$: Wellbore Flowing Pressure (psi)

$P_{i}$: Average Pressure (psi)

$\Delta p_{\text {skin }}$: Pressure Drop Due to Skin (psi)

Output(s)

E: Flow Coeffcient (fraction)

Formula(s)

$$ E=\frac{P_{i}-p_{w f}-\Delta p_{s k i n}}{P_{i}-p_{w f}} $$

Reference(s)

Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 1, Page: 64