Provides a dynamic pressure seal around the coiled tubing.
· Allows continuous movement of the tubing in and out of the well.
· Maintains well control and minimizes fluid leakage.
Consequences of failure:
· Pressure leakage
· Increased operational risk
· Unplanned downtime
· Higher maintenance costs
Material selection (based on well conditions):
Material Best For
NBR (Nitrile) General operations and hydrocarbon service (most common).
HNBR Heat, abrasion, and sour service (better resistance than NBR).
Viton (FKM) High temperatures and aggressive chemicals (e.g., acidizing).
Aflas (TFE/P) High-temperature wells with H₂S, steam, and aggressive chemicals.