Pseudo skin factor due to partial penetration (Brons and Marting method)

Input(s)

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

$\mathrm{h}$ : Total pay thickness (ft)

kh: Vertical permeability $(\mathrm{mD})$

$\mathrm{kv}$ : Horizontal permeability $(\mathrm{mD})$

rw: Wellbore diameter (ft)

Output(s)

$h_{d}$ : Dimensionless Payzone Thickness (dimensionless)

b: Penetration Ratio (dimensionless)

$\mathrm{Gb}$ : Function for penetration ratio (dimensionless)

$s_{p}$ : Skin due to partial penetration (dimensionless)

Formula(s)

$$ \begin{gathered} h_{d}=\frac{h_{p}}{h} \\ b=\frac{h}{r w} *\left(\frac{k h}{k v}\right)^{0.5} \\ G b=2.948-7.363 * b+11.45 * b^{2}-4.675 * b^{3} \\ s_{p}=\left(\frac{1}{b}-1\right) *\left(\ln \left(h_{d}\right)-G b\right) \end{gathered} $$

Reference(s)

Horizontal Well Technology, Joshi, Page: 493.