Investigation Report
Uncontrolled Top Drive Descent During Wireline Operations and Drawworks Maintenance
06-04-2006 07:03 G11081 GC/645 Top Drive Unplanned Descent
- BSEE
- Investigation Report
- Unknown
- Dropped objectsMechanical failure
- DrillingInspection and maintenance
- WinchWire rope
- Operating and work procedures
- Upstream oil and gas
- Offshore installation
Summary
Investigation of an uncontrolled top-drive descent on Holstein Spar during wireline operations and drawworks air-system maintenance. Worn brake friction pads exceeded parking-brake capacity as dynamic-brake pressure was reduced. Emergency stops did not halt the descent. Electric line was severed; no injuries and minor property damage were reported.
Classifications: Dropped objects; falling objects; DROPS.
Classifications: Mechanical failure; equipment failure.
Classifications: Drilling; well drilling.
Classifications: Inspection and maintenance; asset inspection; equipment maintenance.
Classifications: Winch; winches.
Classifications: Wire rope; steel wire rope.
Classifications: Operating and work procedures.
Classifications: Upstream oil and gas; oil and gas extraction; upstream petroleum.
Classifications: Offshore installation; offshore platform; offshore rig.