Mechanical Specific Energy Formula
Mechanical Specific Energy calculates mechanical specific energy for drilling operations and economics workflows in drilling engineering.
How engineers use this formula
Use this formula when the listed inputs (WOB, A_b, N, T, ROP) are known and the assumptions behind the cited drilling operations and economics relationship match the engineering case being checked.
Assumptions
- Input values are representative for the well, reservoir, fluid, or equipment case being evaluated.
- The declared units match the field-unit constants used in the formula.
- The cited formula applies to the selected petroleum engineering workflow.
Limitations
- The calculation does not replace a full engineering model or operating procedure.
- Accuracy depends on the source correlation, assumptions, input quality, and unit consistency.
Common mistakes
- Mixing unit systems without converting the inputs.
- Using default example values as field recommendations.
- Applying the formula outside the source assumptions.
Default example
Using the default inputs, MSE equals 80,251.888645 psi.
30000
56.745
120
5000
50
Inputs
WOB
lbfWeight on bit
A_b
in^2Bit area
N
rev/minRotary speed
T
ft*lbfRotary torque
ROP
ft/hRate of penetration
Outputs
MSE
Mechanical specific energy
WOB
Weight on bit
A_b
Bit area
T
Rotary torque
ROP
Rate of penetration
Source and review
reviewed501 Solved Problems and Calculations for Drilling Operations, Robello, S.E. (2015)
Samuel, E. Robello. 501 Solved Problems and Calculations for Drilling Operations, Sigma Quadrant, Houston, Texas, 2015, Page 414.