Offshore workers and helicopter crew were exposed to large concentrations of “highly flammable” hydrocarbon gas after being sent to a leak on a North Sea platform.
The ten crew members were left stranded on board the normally unmanned platform unable to seek shelter in the appropriate safe havens due to the cloud of un-ignited gas “compromising” escape routes off the platform.
They had been sent to respond to a gas alarm on the Davy platform in the Southern North Sea when they found themselves trapped.
After being dropped off by a helicopter, which then departed, the found themselves in serious danger and unable to reach suitable countermeasures.
Due to the layout of the platform and the position of the gas they were separated from emergency lifesaving gear, such as life jackets and escape equipment.
As well as exposing them to “serious” risk of asphyxiation there was also the possibility of a “fire or explosion”, according to safety watchdogs.
The Health and Safety Executive released a scathing investigation report and prohibition notice into the incident yesterday.
The inspector who ran the probe said: “The location of the gas release – and its associated gas cloud – compromised the designated escape route for all personnel to the temporary refuge and the primary muster point on the installation’s cellar deck, leaving them no option but to muster in an unprotected area below the helideck.
“The flammable gas release, and the potential for its ignition, meant that the preferred means of evacuation from the installation – by helicopter from the helideck – was too dangerous to be used.
“The same compromised route to the cellar deck prevented access by the crew to the installation’s designated means of escape to sea – the Selantic Chute and its associated life-raft – and to any of the crew’s personal protective equipment – personal descent devices, life jackets and abandonment suits, – required to secure a good prospect of survival having escaped to sea.”
The Offshore Installation Manager (OIM) started the emergency shutdown of the platform when the leak was noticed.
But a loss of electrical power to the fire and has panel mean he lost any oversight of the status of the plant and the associated gas, heat and smoke detection elements on the production deck.
The same power loss also stopped the platform from using radios, telephone and microwave links to talk with neighboring control rooms and other oil and gas hubs.
The HSE inspector added: “This prevented the clear and accurate communication with external agencies necessary for the OIM to coordinate an effective emergency response.
“These finding lead me to the opinion that the arrangements and equipment provided for emergency response on the installation as described in the installations emergency response plan did not provide sufficient protection for personnel on the installation during a foreseeable major incident.”
Operator Perenco has confirmed the hydrocarbon release.
A spokesman for the firm said: “Perenco confirms that there was a gas release on the Davy Platform.
“The correct response procedures were followed, which included an emergency shutdown of the platform and notifying The Health & Safety Executive.
“There were no injuries to personnel or damage to equipment.
“Throughout the incident, the crew was supported by a safety standby vessel.
“An investigation into the cause of the release was subsequently launched and is ongoing.”