Skin factor due to reduced crushed-zone permeability

Input(s)

$h_{p}$: Perforation interval (ft)

$\mathrm{kd}$ : Damage Zone permeability $(\mathrm{mD})$

kdp: Crushed Zone Permeability $(\mathrm{mD})$

$\mathrm{k}$: Permeability of Formation $(\mathrm{mD})$

$r_{d p}$: Crushed Zone radius $(\mathrm{ft})$

$r_{p}$: Perforation Radius $(\mathrm{ft})$

Lp: Depth of Penetration (ft)

N: Total Number of Perforations (number)

Output(s)

sc: Skin Factor due to Reduced Crushed-Zone Permeability (dimensionless)

Formula(s)

$$ s c=\left(\frac{k}{k d p}-\frac{k}{k d}\right) * 12 * \frac{h_{p}}{N * L p} * \ln \left(\frac{r_{d p}}{r_{p}}\right) $$

Reference(s)

Horizontal Well Technology, Joshi, Page: 504.