D-Exponent
Input(s)
d: Penetration Rate \((\mathrm{ft} / \mathrm{h})\)
\(\mathrm{N}\): Rotary Speed (rpm)
W: Weight on Bit in 1000lb (lb)
D: Bit Size (in.)
Output(s)
d: D Exponent (dimensionless)
Formula(s)
\[
\mathrm{d}=\frac{\log \left(\frac{\mathrm{R}}{60 * \mathrm{~N}}\right)}{\log \left(\frac{12 * \mathrm{~W}}{1000 * \mathrm{D}}\right)}
\]
Reference(s)
Lyons, W. C., Carter, T., and Lapeyrouse, N. J., 2012, Formulas and Calculations for Drilling, Production and Workover Third Edition Gulf Professional Publishing, Page: 214.