Mechanical specific energy

Input(s)

WOB: Weight on Bit (lbf)

$\mathrm{A}_{\mathrm{b}}$: Area of Bit (in. ${ }^{2}$ )

$\mathrm{N}$: Rotational Speed of Bit (in./m)

$\mathrm{T}$: Torque of Bit (lbf in.)

ROP: Rate of Penetration (m/in.)

Output(s)

MSE: Mechanical Specific Energy (lbf/in. ${ }^{2}$ )

Formula(s)

$$ \mathrm{MSE}=\left(\frac{\mathrm{WOB}}{\mathrm{A}_{\mathrm{b}}}\right)+\left(\frac{120 * \pi * \mathrm{~N} * \mathrm{~T}}{\mathrm{~A}_{\mathrm{b}} * \mathrm{ROP}}\right) $$

Reference(s)

Samuel. E Robello. 501 Solved Problems and Calculations for Drilling Operations. Sigma Quadrant. 2015. Houston, Texas, Page: 414.