Skin factor for a deviated well
Input(s)
ө: Angle of Inclination (degree)
kv: Vertical Permeability \((\mathrm{mD})\)
kh: Horizontal Permeability \((\mathrm{mD})\)
\(\mathrm{h}\) : Formation Thickness (ft)
rw: Radius of Wellbore \((\mathrm{ft})\)
s: Total Skin Factor (dimensionless)
Output(s)
tw: Angle of Inclination due to drilling (degree) \(h_{d}\) : Dimensionless Effective Thickness (dimensionless)
\(s_{t h}\) : Directional Drilling Skin Factor (dimensionless)
\(s_{t}\): Skin Factor other than Directional Drilling (dimensionless)
Formula(s)
\[
\begin{gathered}
t w=\left(\operatorname{atan}\left(\left(\frac{k v}{k h}\right)^{0.5} * \tan \left(\theta * \frac{\pi}{180}\right)\right)\right) * \frac{180}{p i} \\
h_{d}=\left(\frac{h}{r w}\right) *\left(\frac{k h}{k v}\right)^{0.5} \\
s_{t h}=-\left(\frac{t w}{41}\right)^{2.06}-\left(\frac{t w}{56}\right)^{1.865} * \log \left(\frac{h_{d}}{100}\right) \\
s_{t}=s-s_{t h}
\end{gathered}
\]
Reference(s)
Pressure Transient Testing, Lee, Rollins & Spivey, Page: 44.