Time to reach the semi-steady state for a gas well in a circular or square drainage area (1)
Input(s)
\(\mu_{\mathrm{gi}}\): Initial Gas Viscosity (cP)
\(\emptyset\): Porosity (fraction)
\(\mathrm{c}_{\mathrm{ti}}\): Initial Total Compressibility (1/psi)
A: Drainage Area \(\left(\mathrm{ft}^{2}\right)\)
\(\mathrm{k}\): Effective Gas Permeability \((\mathrm{mD})\)
Output(s)
\(\mathrm{t}_{\mathrm{pss}}\): Time (h)
Formula(s)
\[
\mathrm{t}_{\mathrm{pss}}=\frac{15.8 * \emptyset * \mu_{\mathrm{gi}} * \mathrm{c}_{\mathrm{ti}} * \mathrm{~A}}{\mathrm{k}}
\]
Reference(s)
Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3, Page: 194.