The UK Health & Safety Executive (HSE) feared catastrophic consequences on Shells Brent Charlie platform because the scale of a long-running series of gas leaks meant ignition was almost inevitable, documents reveal.
ROB WATTS London 05 August 2011 01:39 GMT
Leaked documents and others obtained by Upstream under UK freedom of information (FoI) legislation shed further light on the complex safety problems Shell is battling on the ageing North Sea facility.
One leaked document, dated 18 July, said Shell is facing a 15,000-hour maintenance backlog on mechanical equipment. This is on top of the extensive work it is undertaking to overcome leaks of hydrocarbon gas and hydrogen sulphide known as glugs that have led to the shutdown of the platform and 30,000 barrels of oil equivalent per day of output.
The HSE said more staff should be devoted to reducing the maintenance backlog.
The periodic releases happen when gases build up in Brent Cs large inter-connected concrete oil and produced water storage cells on the seabed and migrate or glug into one of its legs, Column C1. These releases are contained by a gas-tight floor before a venting system diverts the gas into the atmosphere and away from the platform.
However, Shell has experienced difficulties in doing this effectively and in calm weather gas has been detected on the topsides.
Upgrades to the venting system are taking place and Shell aims to restart the platform in January 2012.
The 18 July document sent by the HSE to Shell after an inspection on 30 and 31 May this year also reveals that inspectors found areas of the platform suffering from severe corrosion.
Concerns that elected workforce safety representatives on Brent C have not been involved properly in reviewing options to resolve the glug problems were also raised.
The HSE told Upstream: While some operational personnel have been involved, the level of safety reps involvement in reviewing the solutions to the glug issues needs to be improved to demonstrate effective workforce involvement.
The HSE wants Shell to focus on overcoming corrosion but added: Corrosion will always be an issue on an installation of this age and it was evident that work was ongoing to address this, for example handrail and grating replacement.
A document obtained under FoI rules details notes of a meeting between Shell and HSE officials at the Anglo-Dutch supermajors Aberdeen offices on 17 January this year, five days after gas was detected on Brent Cs topsides after a glug.
In the the papers, the HSE said: It is considered that for releases of this scale, ignition of such a cloud is almost inevitable and that it is foreseeable that the consequences could be catastrophic.
Oil and gas exports have been shut in since the 12 January release, with a well designed to provide feedstock for power generation shut in on 15 July, following a deferred Prohibition Notice issued by the HSE.
This followed another release on 28 June, when oil and produced water flooded into the C1 leg after pumps failed.
Shell told Upstream this week: Our work on Brent Charlie continues to progress. Consultation with staff is a standard requirement when a safety case is updated or changed. There will be further consultation on the final format of the updated section of the safety case.
Production will not resume until all necessary work is complete. We are currently working towards a restart date of early 2012.
Brent Charlie, in Block 211/29 of the northern North Sea, has been producing since 1976.
Shell chief executive Peter Voser admitted the company he leads does make mistakes about safety but insists it is constantly learning from them.
Do we make mistakes? Yes, we do make mistakes, but we learn from and we avoid them in the future, Voser said last week.
Voser was responding to a question about UK North Sea safety during a conference call with media to discuss Shells second-quarter results.
He said: We have had leaks, we are learning out of them, we are containing them immediately and I think that is the way to improve in the longer term.
Our safety record has been improving all the time, not just in the UK but also on a global basis. I think we are recognised as a leader in this field.
Let me be clear that safety is a key component of our thinking on how we operate our assets. We are constantly improving and we are learning, he said.
Published: 05 August 2011 01:39 GMT | Last updated: 05 August 2011 04:28 GMT