d index online calculator

App Description

Enter the value and click "Calculate" to display the result

R = permeability

N = rotation speed

W = drill pressure

D = drill diameter

ρ_n = mud equivalent

ρ_m = 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.

Usage example

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