# 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.