# 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.

## Related

### Skin factor

An unhandled error has occurred. Reload 🗙