Enter the value and click "Calculate" to display the result
R = permeability
N = rotation speed
W = drill pressure
D = drill diameter
ρn = mud equivalent
ρm = mud weight
C = mud slate compaction coefficient
This concept was first developed by Jordan and Shirley. This is a factor in evaluating drilling speed and predicting abnormal pore pressure zones.
All things are equal, and the d-index should increase with depth when drilling holes in normal pressure. The reversal of this trend is that drilling indicates potential overpressure.
Input data: Permeability: 10Ft / Hr; Rotation speed: 20Rev / Minute; Drilling pressure: 20 1000 Lb; Drill diameter: 10Inches; Slurry equivalent: 60Lb / Gal; Mud weight: 40Lb / Gal; Mud slate compaction coefficient: 6
Click on "Calculate", d index: 14.6211