Skin during infinite-acting pseudoradial flow for vertical wells
Input(s)
\(p_{i}\): Initial Pressure \((\mathrm{psi})\)
\(p_{1 h r}\): Pressure After 1 Hour (psi)
\(\mathrm{m}\): Slope \((\mathrm{psi} / \mathrm{h})\)
k: Permeability \((\mathrm{mD})\)
\(\emptyset\): Porosity (fraction)
\(\mu_{\text {Total }}\): Viscosity \((\mathrm{cP})\)
\(c_{t}\): Total Compressibility (1/psi)
\(r_{w}\): Wellbore Radius (ft)
Output(s)
S: Skin (dimensionless)
Formula(s)
\[
S=1.151 *\left(\left(\frac{p_{i}-p_{1 h r}}{m}\right)-\log \left(\frac{k}{\emptyset * \mu_{\text {Total }} * c_{t} * r_{w}^{2}}\right)+3.23\right)
\]
Reference(s)
Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 1, Page: 99