Stripping/snubbing calculations - Minimum surface pressure before stripping

Input(s)

$W_{c}$: Weight per feet of one stand of Drill Collar (lb/ft)

$\mathrm{L}$: Length of one stand (feet)

D: Drill Collar Dia (in.)

Output(s)

$P_{\min }$: Minimum surface Pressure before stripping is possible (psi)

Formula(s)

$$ P_{\min }=W_{c} * \frac{L}{D^{2} * 0.7854} $$

Reference(s)

Formulas and Calculations for Drilling, Production and Workover, Second Edition, Lapeyrouse, Page: 141.