Uncontrolled release of wellbore gas at surface during slickline plug retrieval operations resulting in well control incident.
Slickline operation. While POOH FBN plug retrieval tool, observed a gas leak on lubricator stuffing box. Attempted to increase the pressure of the stuffing box, no success. Activated BOP upper blind rams, observed it closed but gas still leaking. Attempted to close lower rams, no success. Observed a leak in the hydraulic connection. Cut cable and shut well in by closing Xmas tree master valve.
What Went Wrong?:
- Failure of stuffing box preparation (wrong packing elements installed)
- Failure in PCE preparation (equalizing port left open - bypassing the rams)
- Failure of hydraulic connection - not tested
- Decision to secure the well by shut in at the Xmas tree and cut the cable delayed due to lack of emergency procedure and clear responsibilities established
Corrective Actions and Recommendations:
- Pressure Control Equipment is valid only if Certified / Inspected / Maintained / Tested
- Responsibilities and Emergency Responses procedures to be defined before the operations
- Well Intervention supervisor to verify PCE status and Referential compliance
safety alert number: 310
IOGP Well Control Incident Lesson Sharing http://safetyzone.iogp.org/
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