Formula 1.86

Low-pressure region gas flow rate for non-circular drainage area

Input(s)

$\mathrm{k}$: Permeability $(\mathrm{mD})$

$\mathrm{h}$: Thickness (ft)

$P_{r}$: Average Reservoir Pressure (psi)

$P_{w r}$: Well Flowing Pressure (psi)

$\mu_{\text {gavg }}$: Average Gas Viscosity (cP)

$Z_{\text {avg }}$: Average Gas Compressibility Factor (Dimensionless) A: Drainage Area $\left(\mathrm{ft}^{2}\right)$

$C_{A}$: Shape Factor (dimensionless)

$r_{w}$: Wellbore Radius (ft)

S: Skin (dimensionless)

T: Temperature $(\mathrm{R})$

Output(s)

$Q_{g}$: Gas Flow Rate $(\mathrm{MSCF} /$ day $)$

Formula(s)

$$ Q_{g}=\frac{k * h *\left(\left(P_{r}^{2}\right)-\left(\left(P_{w f}\right)^{2}\right)\right)}{1422 * \mu_{\text {gavg }} * T * Z_{\text {avg }} *\left(0.5 * \ln \left(\frac{4 * A}{1.781 * C_{A} *\left(r_{w}^{2}\right)}\right)+S\right)} $$

Reference(s)

Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3, Page: 189.