Preliminary Learning Points

1
Shell EPW - RTD HSE Early Learning Bulletin
Fountain No 308737 Location CAN -
Unconventional Gas Date 5 Oct 2008
What Happened FA (HPI) ROTATING HEAD FAILURE -
While reaming to bottom in 12 1/4" hole with WBM
at 1.8m3/min and nitrogen injection at 1.8m3, the
retaining clamp on the top of the Smith rotating
head (Model DHS 1400) released. (The head had
been installed /- 8 hours earlier) The force of
the liquid/gas mixture caused the stripper rubber
to rise up the drill pipe. The force of the
stripper rubber and liquid passing through the
rotary table caused the rotary bushings to jump
from the master bushing. The rotary bushings
came to rest approximately 1m from the well
centre. The motor man, who had been lubricating
the stripper rubber/drill pipe by pouring WBM on
to the top of the rubber moments before, was
knocked to floor by the force of the mud flow.
While attempting to clear the drill floor he
struck his head on a rig tong causing a small cut
that required first aid.

• Preliminary Learning Points
• The RCD had been installed 8 hours earlier in the
  same manner as previous installations as per the
  August 2008 JSA provided by Smith.
• After installation no further check on bolt MU
  had been made (Smith JSA requires checking MU
  after 24 hours).
• There was no retaining mechanism on the collar
  that would prevent the bolt/nut assembly from
  sliding off in the event the bolt started to back
  off.
• Equipment was being operating within its design
  parameters.
• Rotary bushing was not locked which allowed it to
  rise from the drill floor when struck by the
  fluid flow.
• Inspection of the clamp during operations was not
  always completed on a daily basis.
• Procedures for lubricating rotary head (worker
  stands over rotary table) need to be amended to
  remove worker from line of fire.
• Smith is reviewing the clamp design for use on
  future wells.

Position rotary bushings came to rest in
Interim repair with safety pin installed and
upsets added to the clamp to prevent the nut/bolt
slipping off the clamp face if it becomes loose
Re-Enactment
This Learning Bulletin provides preliminary
learnings. A detailed investigation is pending.
For internal use only.