Hydromechanical specific energy
Input(s)
WOB: Weight on Bit (lbf)
\(\mathrm{A}_{\mathrm{b}}\): Area of Bit \(\left(\mathrm{ft}^{2}\right)\)
\(\mathrm{N}\): Rotational Speedfor a Bit \((\mathrm{ft} / \mathrm{s})\)
\(\eta\): Factor for Energy Reduction (dimensionless)
\(\mathrm{P}_{\mathrm{b}}\): Presure Drop Across Bit (psi)
Q: Flow Rate \(\left(\mathrm{ft}^{3} / \mathrm{s}\right)\)
ROP: Rate of Penetration \((\mathrm{s} / \mathrm{ft})\)
T: Torque (lbf ft)
Output(s)
HMSE: Hydro Mechanical Specific Energy \(\left(\mathrm{lbf} / \mathrm{ft}^{2}\right)\)
Formula(s)
\[
\mathrm{HMSE}=\left(\frac{\mathrm{WOB}}{\mathrm{A}_{\mathrm{b}}}\right)+\left(\frac{120 * 3.142 * \mathrm{~N} * \mathrm{~T}+1154 * \eta * \mathrm{P}_{\mathrm{b}} * \mathrm{Q}}{\mathrm{A}_{\mathrm{b}} * \mathrm{ROP}}\right)
\]
Reference(s)
Samuel. E Robello. 501 Solved Problems and Calculations for Drilling Operations. Sigma Quadrant. 2015. Houston, Texas, Page: 415.