Formula 4.71
Pseudo-skin factor due to partial penetration (Yeh and Reynolds correlation)
Input(s)
$h_{p}$: Perforation Interval $(\mathrm{ft})$
$\mathrm{h}$ : Total pay thickness $(\mathrm{ft})$
$C_{d}$ : Location of open interval from graphical co-relation by Yeh and Ronald (dimensionless)
$k_{v}$ : Horizontal Permeability $(\mathrm{mD})$
$k_{h}$ : Vertical Permeability (mD)
$r_{w}$: Wellbore Dia (ft)
Output(s)
b: Penetration ratio (dimensionless)
$C_{1}$ : Location of open interval from graphical co-relation by Yeh and Ronald (dimensionless)
$h_{d}$ : Dimensionless payzone thickness (dimensionless)
$h_{\{w d\}}$ : Effective Wellbore depth (ft)
$s_{p}$: Skin due to partial penetration (dimensionless)
Formula(s)
$$ \begin{gathered} b=\frac{h_{p}}{h} \\ C_{1}=\frac{h}{r_{w}} * \operatorname{sqrt}\left(\frac{k_{h}}{k_{v}}\right) \\ h_{d}=0.481+1.01 * b-0.838 * b^{2} \end{gathered} $$
$$ \begin{gathered} h_{w d}=C_{d} * b *(1-b) * \frac{h_{d}}{2.71_{1}^{C}} \\ s_{p}=\frac{1-b}{b} * \ln \left(h_{\{w d\}}\right) \end{gathered} $$
Reference(s)
Horizontal Well Technology, Joshi, Page: 496.