Bottomhole assembly length required for a desired weight on bit

Input(s)

$\mathrm{W}_{\mathrm{b}}$: Desired Weight to be used while Drilling (lb)

f: Safety Factor (fraction)

$\mathrm{W}_{\mathrm{d}}$: Drill Collar Weight $(\mathrm{lb} / \mathrm{ft})$

BF: Buoyancy Factor (unitless)

Output(s)

L: Length of Bottomhole Assembly (ft)

Formula(s)

$$ \mathrm{L}=\frac{\mathrm{W}_{\mathrm{b}} * \mathrm{f}}{\mathrm{W}_{\mathrm{d}} * \mathrm{BF}} $$

Reference(s)

Lapeyrouse, N. J., 2002, Formulas and Calculations for Drilling, Production and Workover, Second Edition, Gulf Professional Publishing, Page: 42.