d-Exponent Calculator

Enter value and click on calculate. Result will be displayed.
`d=([log R/[60×N]]/[log [12×W]/[1000×D]])×(ρ_n/ρ_m)^c `
R = Penetration Rate      N = Rotary Speed
W = Weight on Bit      D = Drill Bit Diameter
ρn = Mud Weight Equivalent      ρm = Mud Weight Used
C = Shale Compactibility Coefficient

Enter Your Values:

Penetration Rate:
Ft / Hr
Rotary Speed:
Rev / Minute
Weight on Bit:
1000 Lb
Drill Bit Diameter:
Inches
Mud Weight Equivalent:
Lb / Gal
Mud Weight Used:
Lb / Gal
Shale Compactibility Coefficient:

Result:

d-Exponent:
d-Exponent Calculator

This concept was first developed by Jorden & Shirley This is a factor for evaluating drilling rate and predicting abnormal pore pressure zones.

All things being equal, the d-exponent should increase with depth when drilling in a normal pressure section. A reversal of this trend is an indication of drilling into potential overpressures.
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