Annular Capacity Calculator
What is Annular Capacity and how do we use it?
Annular capacity is the volume of fluid that can be held in the annulus between the drill string (or liner/casing) and the borehole.
The annular capacity is calculated using the hole diameter and the pipe or casing diameter.
The calculation for total volume in the annulus is based on taking the area between the pipe and hole and multiplying it by the length of the annulus.
Annular Capacity:
Total Volume:
Formula:
The annular capacity is calculated using the formula:
Annular Capacity = ((Pipe OD² - Hole ID²) / 1029.4) * Annular Length
Variables:
- Pipe Area: The area of the pipe (in²)
- Hole Area: The area of the hole (in²)
- Annular Length: The length of the annulus (ft)