Drilling EngineeringDrilling Hydraulics
Overall Power System Efficiency Formula
Overall Power System Efficiency calculates overall power-system efficiency for drilling hydraulics workflows in drilling engineering.
How engineers use this formula
Use this formula when the listed inputs (P, Q_i) are known and the assumptions behind the cited drilling hydraulics 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, E_i equals 0.285714 fraction.
Php
1000
Q_ihp
3500
Inputs
P
hpPower output
Q_i
hpInput heat energy rate
Outputs
E_i
fraction
Overall power-system efficiency
P
hp
Power output
Q_i
hp
Input heat energy rate
Source and review
reviewedApplied Drilling Engineering, Bourgoyne, A.T., Millheim, K.K., Chenevert, M.E., Young, F.S. (1986)
Bourgoyne, A.T., Millheim, K.K., Chenevert, M.E., and Young, F.S. 1986. Applied Drilling Engineering, Society of Petroleum Engineers, Page 7.
source conflict
Source