Pressure drop across perforations in gas wells
Input(s)
\(q_{g}\): Gas Flow Rate through Perforation \((\mathrm{bbl} / \mathrm{d})\)
\(n\): Number of Perforations (dimensionless)
\(\mu_{g}\): Gas Viscosity (cP)
\(Z\): Gas Supercompressibility Factor (dimensionless)
T: Formation Temperature \(\left(\mathrm{R}^{\circ}\right)\)
\(L_{p}\) : Perforation Length (ft)
\(k_{p d}\): Perforation Damaged Zone Permeability (mD)
\(r_{p}\) : Perforation Radius ( \(\mathrm{ft}\) )
\(r_{p d}\): Perforation Damaged Zone Radius (ft)
\(\gamma_{g}\): Gas Specific Gravity \((\) air \(=1.0)\)
Output(s)
\(p_{s f}\): Pressure at the Sandface (psi)
\(p_{w b}\) : Pressure in the Wellbore (psi)
\(\beta_{p d}\) : Velocity Coefficient of Turbulence Factor \((1 / \mathrm{ft})\)
Formula(s)
Reference(s)
Bell, W. T., Sukup, R. A., & Tariq, S. M. (1995). Perforating. Henry L. Doherty Memorial Fund of AIME, Society of Petroleum Engineers, Page: 62.