Performance coefficient for shallow gas reservoirs

Input(s)

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

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

$\mathrm{T}$: Temperature $\left({ }^{\circ} \mathrm{R}\right)$

$\mu$: Viscosity (cP)

z: Compressibility Factor (dimensionless)

$\mathrm{r}_{\mathrm{e}}$: Radius of Drainage Area $(\mathrm{ft})$

$\mathrm{r}_{\mathrm{w}}$: Wellbore Radius $(\mathrm{ft})$

Output(s)

C: Performance Coefficient (dimensionless)

Formula(s)

$$ \mathrm{C}=\frac{\mathrm{k} * \mathrm{~h}}{1422 * \mathrm{~T} * \mu_{\mathrm{g}} * \mathrm{Z} *\left(\ln \left(\frac{\mathrm{r}_{\mathrm{e}}}{\mathrm{r}_{\mathrm{w}}}\right)-0.5\right)} $$

Reference(s)

Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3, Page: 287.