Gas material balance equation
Input(s)
\(\frac{\mathrm{P}_{\mathrm{i}}}{\mathrm{z}_{\mathrm{i}}}\): Ratio of Pressure to Compressibility Factor at Initial Conditions (psi)
\(\mathrm{P}_{\mathrm{SC}}\): Pressure at Standard Conditions (psi)
\(\mathrm{T}_{\mathrm{SC}}\): Temperature at Standard Conditions \(\left({ }^{\circ} \mathrm{R}\right)\)
T: Current Temperature \(\left({ }^{\circ} \mathrm{R}\right)\)
V: Original Gas Volume \(\left(\mathrm{ft}^{3}\right)\)
\(\mathrm{G}_{\mathrm{p}}\): Cumulative Gas Production \((\mathrm{SCF})\)
Output(s)
\(\frac{\mathrm{P}}{\mathrm{z}}\): Ratio of Pressure to Compressibility Factor at Current Conditions for \(\mathrm{P} / \mathrm{z}\) vs \(\mathrm{G}_{\mathrm{p}}\) plot (psi)
Formula(s)
Reference(s)
Ahmed, T., McKinney, P.D.2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3, Page: 203.