Mud system · Drilling
Mud Tanks
Steel tanks that hold the drilling fluid on the rig. On land rigs they are usually rectangular pits of about 200 barrels each, connected in series.
What it does
Hold the active fluid that circulates through the borehole and back. A kick, an unplanned flow of formation fluid into the well, adds volume to that active system, so the tank volume is watched.
Basics
| Land rigs | Rectangular steel pits, about 200 bbl each |
| Offshore | Built into the vessel, up to about 1,000 bbl |
| Fluid types | Water based, nonaqueous or gaseous |
Common failures
- An influx from the formation that goes unnoticed
Troubleshooting
- Symptom
- Tank volume rises without a reason
- Likely cause
- Kick, formation fluid entering the well
- What to check
- Follow the well control procedure and shut in the well