Formula 3.57

Time to reach the semi-steady state for a gas well in a circular or square drainage area (2)

Input(s)

$\mu_{g i}$: Initial Gas Viscosity $(\mathrm{cP})$

$\emptyset$: Porosity (fraction)

A: Drainage Area $\left(\mathrm{ft}^{2}\right)$

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

$c_{t i}$: Initial Total Compressibility $(1 / \mathrm{psi})$

Output(s)

$t_{p s s}$: Time (h)

Formula(s)

$$ t_{p s s}=\frac{15.8 \phi * \mu_{g i} * c_{t i} * A}{k} $$

Reference(s)

Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3, Page: 194.