The UK Health & Safety Executive (HSE) has taken the rare step of ordering a thorough safety review at Shells Brent Charlie platform following two major gas leaks.
ROB WATTS London 06 May 2011 01:53 GMT
The HSE has told Shell to submit a revised safety case for the Brent Charlie platform after gas was detected on its topsides following leaks on 12 January this year and 27 September 2010, Upstream can reveal.
Shell, which took the decision itself to close the platform after the January incident, has been battling for some time to resolve technically complex issues related to the venting of gas from inside one the platforms huge concrete legs Column 1 (C1) and dispersing it effectively away from the platform.
The operator now expects the ageing Brent field to remain shut down for several more months.
Gas can build up periodically in some of the platforms large concrete storage cells on the seabed, where oil and produced water are stored after processing, and can then migrate into the C1 leg. This is called a glug.
The Brent field has been shut-in since mid-January when a 25-tonne protective fender fell from the Brent Bravo platform into the sea, two days after the gas leak that prompted Shell to shut in Brent Charlie.
The Anglo-Dutch operator has been working since to resolve the two separate problems.
Shell told Upstream: Production will not resume until all necessary work is done and we now expect that could be some months rather than weeks.
The HSE said: We can confirm that Shell… has been directed by HSE to prepare a revision of the Brent Charlie safety case and resubmit the safety case to HSE for assessment.
The regulator said that the current safety case does not adequately consider the major accident hazard arising from the uncontrolled release of flammable or explosive substances from the storage cells into Column 1.
Brent Charlie will remain shut in if the HSE is not satisfied Shell has found a solution that mitigates the risk of a major incident happening.
The request from the HSE is understood to be one of the first since the UKs goal-setting offshore safety regime was introduced in the wake the 1988 Piper Alpha disaster.
It could also mark an apparent willingness on the part of the regulator to use an unconventional method of enforcing offshore safety requirements, normally done using Improvement or Prohibition notices.
Oil and gas installations off the UK cannot operate without an approved safety case.
Shell said: The safety case for Brent Charlie has not been withdrawn. The HSE has asked Shell to provide more detail on the part of the safety case which relates to Column 1.
There was a glug in 2010. After another occurred on 12 January 2011 Shell made the decision to shut down the platform.
The additional material for the safety case was requested after the January 2011 incident. We are working towards restarting production as soon as safely possible.
Shell confirmed it is also facing other issues at Brent Charlie, including the thinning of export pipeline walls, which will also have to be overcome before the platforms can be restarted.
Published: 06 May 2011 01:53 GMT | Last updated: 06 May 2011 08:19 GMT