Oil major BP said today that it had to shut the gas plant on its Glen Lyon FPSO twice after detecting a leak last week.
BP said it halted the gas plant’s operations before reporting the leak to the UK’s Health and Safety Executive (HSE) and replacing a faulty valve.
The company brought the gas plant back online, but following further checks it decided to shut it down once more.
The gas plant was restarted again yesterday.
It is understood that the FPSO continued to produce while the gas plant was shut down, but at a reduced rate.
HSE said it was aware of the incident and that it had served BP with a prohibition notice, which dictates that work on a particular process must stop immediately.
The FPSO is stationed west of Shetland at BP’s flagship Quad 204 development, which started production in May.
Operator BP and partners Shell and Siccar Point Energy expect the mega-project to deliver 450million barrels of oil equivalent (boe) from the Schiehallion and Loyal fields through to 2035 and beyond.
A spokeswoman for BP said: “Following the identification of a leak on one of the Glen Lyon FPSO’s gas compression valves, the gas plant was immediately shut down and we reported the incident to the HSE.
“We then replaced the valve and, following a start-up safety review, brought the gas plant back online.
“Following further assessment, BP proactively shut down the gas plant to carry out additional assurance on the valve. Having completed that assurance, the gas plant was restarted yesterday.
“We acknowledge the HSE’s notice and were compliant with it ahead of the gas plant restart.”
An HSE spokesman said: “HSE was made aware of an issue late last week, relating to a failed stem seal on a valve.
“Remedial work was undertaken by the company but there were still uncertainties about how to maintain the seal.
“The company started up the compression while still trying to resolve those uncertainties.
“HSE served a prohibition notice and we are told the company hopes to start up after resolving the root cause and the maintenance issue.”