Dropped guide sheave roller to drill floor

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Alert ID: 
Description of Task: 

At approximately 19:00hrs as part of the on-going drilling operation, the drill crew, along with various vendor Crews, were running a dual ESP completion and cables.  After unlatching the side door elevators from the string at the rotary table, a hinged roller unit was observed dropping onto the Drill Floor, landing next to the V Door, around 4ft from the nearest member of the team. The unit fell approximately 40ft and weighed 4.5kg.

The cables were being fed from the cable drums situated on the pipe deck, 40ft up through the guide sheave and back down to the drill floor where the cables are clamped onto the completion then run into the well. 

A member of the drill crew alerted the other members of the work party to the incident and stopped the job.  Signs and barriers were erected and the drilling supervision team were informed. A time out for safety stand down was conducted. 

The Senior Tool Pusher spoke to members of the work party who were in close proximity of the landing area to ensure they were fit and un-distressed.

Upon inspection of the roller unit it was found that the ‘R-Clip’ which was used for retaining the hinge pins of the roller unit were no longer in place allowing the hinged roller unit to come apart from the saddle. 

Lessons Identified: 
  • The use of R-Clips attached to retaining chains on a moving item, in close proximity to another item will pose the risk of the R-Clips being inadvertently removed if the retaining chain gets caught and becomes tight.
  • It had not been highlighted by the supplier of the R-Clip that they had the potential for the clips to wear loose under frictional constraints.
  • Due to the R–Clips being certified as fit for purpose, no inspection schedule was required which would have identified the issue.
  • Replace all R-Clips with split pins.
  • Every 10 joints during integrity testing, a visual inspection is to take place on the cable sheave.
  • Highlight visibility of replacement split pins by spray painting to clearly mark these.
  • Prevent collision of sheaves by fitting lateral retention lines.
  • Ensure area has appropriate signs and barriers with the drop zone identified.
Specific Equipment: 

Hinged roller unit and R Clip.

Incident consequence: 
Not Assigned
Drilling, workover
Drilling unit
Cause of accident or incident: 
Not Assigned