Drilling EngineeringDrilling Hydraulics
Percentage Pressure Loss at Bit Formula
Percentage Pressure Loss at Bit calculates percentage pressure loss at bit for drilling hydraulics workflows in drilling engineering.
How engineers use this formula
Use this formula when the listed inputs (P_b, P_s) 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, P_psib equals 40 percent.
P_bpsi
1200
P_spsi
3000
Inputs
P_b
psiBit Nozzle Pressure Loss
P_s
psiSurface Pressure
Outputs
P_psib
percent
Percentage Pressure Loss at Bit
P_b
psi
Bit Nozzle Pressure Loss
P_s
psi
Surface Pressure
Source and review
reviewedLapeyrouse, N.J. Formulas and Calculations for Drilling, Production and Workover, 2nd Edition, Page 170.
Source