Pore volume through squared method in tight gas reservoirs
Input(s)
$\mu_{\mathrm{g}, \text { avg: }} \(Average Gas Viscosity\)(\mathrm{cP})$
\(\mathrm{z}_{\mathrm{avg}}\): Compressibility Factor (dimensionless)
\(\mathrm{q}_{\mathrm{i}}\): Initial Gas Rate (MSCF/day)
\(\mu_{\mathrm{gi}}\): Initial Gas Viscosity \((\mathrm{cP})\)
\(\mathrm{c}_{\mathrm{ti}}\): Initial Total Compressibility \((1 / \mathrm{psi})\)
\(\mathrm{P}_{\mathrm{i}}\): Initial Pressure (psi)
\(\mathrm{P}_{\mathrm{wf}}\): Bottom-hole Flowing Pressure (psi)
\(\mathrm{D}_{\mathrm{i}}\): Decline Rate \(\left(\mathrm{day}^{-1}\right)\)
\(\mathrm{T}\): Temperature \(\left({ }^{\circ} \mathrm{R}\right)\)
Output(s)
PV: Pore Volume (dimensionless)
Formula(s)
\[
\mathrm{PV}=\frac{28.27 * \mathrm{~T} * \mu_{\mathrm{g}, \text { avg }} * \mathrm{z}_{\mathrm{avg}}}{\mu_{\mathrm{gi}} * \mathrm{c}_{\mathrm{ti}} *\left(\mathrm{P}_{\mathrm{i}}^{2}-\mathrm{P}_{\mathrm{wf}}^{2}\right)} *\left(\frac{\mathrm{q}_{\mathrm{i}}}{\mathrm{D}_{\mathrm{i}}}\right)
\]
Reference(s)
Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3, Page: 252 .