Hydromechanical Specific Energy Formula
Hydromechanical Specific Energy calculates hydromechanical 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, eta, P_b, Q, 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, HMSE equals 41,072,824.156306 lbf/ft^2.
30000
0.3941
120
5000
0.7
1200
600
50
Inputs
WOB
lbfWeight on bit
A_b
ft^2Bit area
N
rev/minRotary speed
T
ft*lbfRotary torque
eta
dimensionlessHydraulic energy reduction factor
P_b
psiBit pressure drop
Q
gpmFlow rate
ROP
ft/hRate of penetration
Outputs
HMSE
Hydromechanical specific energy
WOB
Weight on bit
A_b
Bit area
eta
Hydraulic energy reduction factor
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 415.