Bit Run Drilling Cost per Foot Formula
Bit Run Drilling Cost per Foot calculates drilling cost per foot for drilling operations and economics workflows in drilling engineering.
How engineers use this formula
Use this formula when the listed inputs (B, C_R, T, t, F) 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, C_T equals 98 $/ft.
50000
1000
40
8
1000
Inputs
B
$Bit cost
C_R
$/hRig cost rate
T
hRotating time
t
hRound-trip time
F
ftFootage drilled per bit
Outputs
C_T
Drilling cost per foot
B
Bit cost
C_R
Rig cost rate
T
Rotating time
t
Round-trip time
F
Footage drilled per bit
Source and review
reviewedFormulas and Calculations for Drilling, Production and Workover, Lapeyrouse, N.J. (2002)
Lapeyrouse, N.J. 2002. Formulas and Calculations for Drilling, Production and Workover, 2nd Edition, Gulf Professional Publishing, Page 28.