Report Findings from the Shell Investigation Team

1
Report Findings from the Shell Investigation Team
2
Agenda

• Brent Bravo
• Summary of what happened on the 1st January 2005
• Results of the Investigation
• Findings and Actions

3

• Situated 116 miles north-east of Shetland
• Concrete Platform
• Exports gas from the rest of the Brent Field into
  the FLAGS pipeline system
• Three legs one accessible (utility shaft), 2
  flooded.

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Key Observations

• The circumstances of this incident and the
  incident of September 11th, 2003 are completely
  different
• At no time during the incident was there a
  hydrocarbon gas atmosphere in the leg
• Both men followed the correct alarm response
  procedures in evacuating the leg
• The platform personnel did an excellent job
  responding to the incident

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What happened

• Normal platform operations prior to incident
• Two Electrical Technicians, on night shift, were
  in the leg at the 76 metre level installing
  services for a planned inspection of pipework
  below the 76 metre level.
• At around 0220 hours both men smelled H2S and at
  the same time 1 of 4 portable gas monitors at the
  worksite alarmed at 5 ppm H2S
• None of the fixed toxic gas monitors nor any of
  the hydrocarbon gas monitors went into alarm.
• Both men donned their Draeger Rebreather sets
  and, in accordance with procedures, started to
  evacuate the leg by climbing the internal stairs.
  
• At the 81 metre level one of the men stopped and
  activated the platform GPA and then continued to
  climb the stairs.

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What happened (cont)

• At a stair landing just below the 124 metre level
  one of the men (Graeme Burns) stopped climbing
  and sat down on the stair landing
• The other man continued to climb the stairs out
  of the leg believing Graeme was taking a rest and
  would soon follow.
• The second man reached the top of the leg at
  0233 hours and informed the leg sentry that
  Graeme was following behind him.
• Several tannoy messages were given by the OIM to
  tell Graeme that the leg was gas free.
• A two man rescue party was sent into the leg and
  found Graeme laying on the stair landing where he
  originally stopped just below 124 metre level.
• Graeme was given CPR by the rescue team and the
  medic was called to the scene.
• The rescue party were unable to resuscitate
  Graeme.

---- EL124 m
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Cause of Death

• The Death Certificate indicates Graeme died as a
  result of a heart attack caused by a coronary
  artery thrombosis.
• We have no further information about the cause of
  death, but what we do know is
• Graeme had a valid UKOAA offshore medical
  certificate
• The gas monitor that alarmed reached a maximum
  H2S value of 6.7 ppm (the other portable showed
  zero, and neither personal meter alarmed during
  the event). The 6.7 ppm is well below the
  Theshold Limit Value - Short-Term Exposure Limit
  of 10 ppm
• All of the gas detectors were independently
  tested and found to be operating correctly
• The rebreather set was also independently tested
  and found to be operating correctly

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Investigation Findings

• H2S in the Leg
• Background
• By design the bottom of the leg contains seawater
  to a depth of approximately 35 metres.
• A consequence of this seawater is that H2S gas is
  produced by naturally occurring Sulphate Reducing
  Bacteria (SRB)
• The H2S is managed by continuous sparging with
  air and diluting with fresh seawater and when
  required chemical treatment.
• The Threshold Limit Value Short Term Exposure
  Limit for H2S exposure is10 ppm (meaning the
  value to which nearly all workers can be exposed
  to for up to four, 15 minute intervals per day
  without adverse health effects).
• Findings
• The seawater had been treated with a chemical
  scavenger a week before the incident
• At the 76 metre level, the reading was 0 ppm in
  the days prior to the event
• The gas monitor that alarmed reached a maximum
  H2S value of 6.7 ppm.
• Laboratory examination of the portable gas
  monitors indicated they were working correctly at
  the time of the incident and giving accurate
  readings.

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Investigation Findings

• Gas Meters
• Background
• The men had in their possession 4 forms of gas
  detection (2 Crowcon Tetra Portables and 2
  personal gas detectors).
• There were 11 fixed detectors at, above, and
  below the 76 metre level where the men were
  working.
• Only one of the detectors gave an indication of
  H2S (one of the Crowcons)
• Findings
• The Crowcon that alarmed reached a maximum H2S
  value of 6.7 ppm.
• It had not been reset at any time during the
  incident or after
• Laboratory examination of the portable gas
  monitors indicated they were functioning normally
  and giving accurate readings

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Investigation Findings

• Draeger Rebreathers
• Background
• Introduced in 2003 on all Shell UK platforms to
  replace existing rebreathers following trials at
  RGIT Montrose.
• The sets are widely used in the military,
  nuclear, mining, and oil and gas industries
• Findings
• Both men had been trained in the use of the
  Draeger sets and had been assessed as leg
  competent
• Based on the video evidence, both men had not
  donned the units in strict accordance with the
  manufacturers recommendations
• Laboratory examination of the unit worn by Graeme
  confirmed it was functioning normally
• Andy reported the unit worn by him was also
  functioning

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Investigation Findings

• Medical Fitness of Personnel Working Offshore
• Background
• The medical fitness requirement for personnel
  working offshore in the UK is the UKOOA Offshore
  Medical.
• The UKOOA medical examination does not require a
  test of aerobic fitness such as the Chester Step
  Test. Although this is still part of the Shell
  Medical examination for offshore staff.
• Findings
• Graeme had a valid UKOOA Offshore Medical
  Certificate

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Investigation Findings

• Other Issues
• Leg Entry Control
• The procedure for the monitoring of personnel
  movements into and out of the leg was not being
  strictly followed in accordance with the OCOP
• Leg Competency Training
• The Leg Competency training in the use of
  portable gas monitors only requires personnel to
  understand the meaning of the alarms not how to
  reset and retest for harmful atmospheres
• Radio Communications
• There was cross-channel interference during radio
  communications
• First Aid Response Time
• The time taken to get First Aid support to
  casualties in the lower half of the leg, when
  using the stairs as access, is longer than the
  Shell standard of 4 minutes

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Immediate Follow-Up Actions (Underway)

• Emergency Escape Rebreather Training
• Immediately re-train all platform personnel in
  the use of the Draeger rebreathers (where
  applicable)
• Show the instruction DVD
• Have an appropriate person (medic, etc.)
  physically demonstrate the use of the equipment
• Encourage people to use the buddy system to
  check each others deployment in the event they
  are ever needed
• Re-emphasise the advantages of the Draeger system
• Carry out practical exercise by donning training
  sets (when available)
• 2. Leg Entry Control
• For the concrete leg platforms, immediately test
  the application of the appropriate leg entry
  Operating Code of Practice (OCOP) to ensure the
  effectiveness of leg registers
• Carry out regular spot checks to identify all
  personnel in the leg at a point in time and then
  validate against the Leg Register detail.

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Follow-Up Actions (Planned)

• 3. Medical Fitness
• Review medical fitness requirements for personnel
  in the legs of concrete gravity base structures
  in consideration of the unique requirements for
  ingress and egress
• 4. Enhanced Training
• As already agreed with the HSE previously,
  enhance rebreather training.
• Review the requirements for Leg Competency and if
  necessary include requirement for training in the
  use of portable gas monitors
• 5. Radio Communications
• Carry out planned work to upgrade radios to avoid
  cross channel interference immediately.
• 6. First Aid Response Time
• Review First Aid response time for casualties in
  concrete legs and ensure the risks are ALARP
• Concrete Leg Working Environment
• Form a joint Shell/Sigma 3 team to evaluate
  additional improvement opportunities specific to
  the unique environment of concrete legs

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Summary

• The circumstances of this incident and the one on
  September 11th are very different
• At no time during the incident was there a
  hydrocarbon gas atmosphere in the leg
• Both men followed the correct alarm response
  procedures in evacuating the leg
• The platform personnel did an excellent job
  responding to the incident
• The Death Certificate indicates Graeme died as a
  result of a heart attack caused by a coronary
  artery thrombosis.
• Graeme had a valid UKOAA offshore medical
  certificate
• The gas monitor that alarmed reached a maximum
  H2S value of 6.7 ppm (the other portable showed
  zero, and neither personal meter alarmed during
  the event). The 6.7 ppm is well below the
  Theshold Limit Value - Short-Term Exposure Limit
  of 10 ppm
• All of the gas detectors were independently
  tested and found to be operating correctly
• The rebreather set was also independently tested
  and found to be operating correctly
• There were other improvement opportunities
  discovered that are being actioned

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Requests of You

• Complete The Ones I already made to you on
  January 7th
• Immediately re-train all platform personnel in
  the use of the Draeger rebreathers (where
  applicable), as per my instruction on January 5th
• For installations using other types of
  rebreathers, do the same with your existing
  training package
• For the concrete leg platforms, continue to test
  your application of the appropriate leg entry
  Operating Code of Practice (OCOP) to ensure the
  effectiveness of leg registers
• New Requests
• Use elements of this slide pack to communicate to
  all platform personnel ASAP
• Re-educate all platform personnel in the dangers
  of hydrocarbon vapour (next slide)
• Confirm to your Ops Manager and Asset Leader via
  email when you have completed these requests
• Ensure these same requests are handed over to
  your back-to-back

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Additional Observations Not Connected with the
Incident
100
A key finding from the September 2003 incident
was a lack of awareness of the risks associated
with the Narcotic Effect of Hydrocarbon
Gas There is evidence that these risks are
still not understood by the workforce. Please
re-communicate the dangers of breathing
hydrocarbon vapour to all members of the
workforce.
Failure to respond to verbal commands
80
60
Hyper-excitation, loss of ability to take
rational decisions
Lower Explosive Limit
40
Likely there is no impairment of functionality
20
10
No impairment of functionality