Formula 3.29

Dimensionless storage constant for gases

Input(s)

$C^{\prime}$: Wellbore Storage $\left(\right.$ tons $\left./\left(\mathrm{kg} / \mathrm{cm}^{2}\right)^{2}\right)$

Z: Real Gas Law Deviation Factor (ratio)

T: Absolute Formation Temperature $\left({ }^{\circ} \mathrm{K}\right)$

M: Molecular Weight $(\mathrm{g} / \mathrm{g} \mathrm{mol})$

$\varnothing$: Porosity (Per cent)

$h$: Net Formation Thickness (m)

$c_{t}$: Total System Effective Isothermal Compressibility $\left(\mathrm{kg} / \mathrm{cm}^{2}\right)^{-1}$

$r_{w}$: Well Radius $(\mathrm{m})$

Output(s)

$C_{D}$: Dimensionless Storage Constant for Gases (dimensionless)

Formula(s)

$$ C_{D}=\frac{27 C^{\prime} Z T}{M \varnothing h c_{t} r_{w}^{2}} $$

Reference(s)

Ramey Jr., H. J. (1981). Reservoir Engineering Assessment of Geothermal Systems. Department of Petroleum Engineering, Stanford University, Page: (5.18).