D-Exponent from Drilling Parameters Formula
D-Exponent from Drilling Parameters calculates d-exponent for drilling operations and economics workflows in drilling engineering.
How engineers use this formula
Use this formula when the listed inputs (R, N, W_k, D_b) 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, d_exp equals 1.571871 dimensionless.
50
120
30
8.5
Inputs
R
ft/hPenetration rate
N
rev/minRotary speed
W_k
1000 lbfWeight on bit
D_b
inBit diameter
Outputs
d_exp
D-exponent
R
Penetration rate
N
Rotary speed
W_k
Weight on bit
D_b
Bit diameter
Source and review
reviewedFormulas and Calculations for Drilling, Production and Workover, Lyons, W.C., Carter, T., Lapeyrouse, N.J. (2012)
Lyons, W.C., Carter, T., and Lapeyrouse, N.J. 2012. Formulas and Calculations for Drilling, Production and Workover, 3rd Edition, Gulf Professional Publishing, Page 214.