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Cold, remote, dispersed and vulnerable

The Snøhvit/Melkøya and Ormen Lange/Nyhamna projects represent Norway’s fi rst integrated offshore-land facilities. Their location, reservoir conditions, development solutions and new technology provide both challenges and opportunities for safety.

A trend towards greater offshore-land integration was a key argument for giving the PSA regulatory responsibility at eight shore-based plants when it began work on 1 January 2004.

Snøhvit in the Barents Sea and Ormen Lange in the Norwegian Sea are Norway’s fi rst offshore developments to be entirely controlled from land – at Melkøya and Nyhamna respectively.  These two facilities are also the fi rst land-based plants for which the PSA has been responsible from the start of construction.

Gas from Snøhvit is piped to Melkøya outside Hammerfest in northern Norway for liquefaction and storage in big tanks before transfer to specialised carriers and shipment to customers. The process has suffered a number of start-up problems, and it remains uncertain whether further modifi cations will be required at the plant.

“This facility has the biggest gas liquefaction train ever built, and is a complex installation with much equipment placed on or alongside a barge which now stands on dry land,” notes Hans Kjell Anvik. He is the PSA’s contact person for land-based plants.

“The high equipment density means that the technical and risk aspects of the design can be compared with conditions on an offshore installation.  “In addition, the plant stands far to the north, exposed to greater cold and more extreme weather than elsewhere in Norway.

“Our constant concern is how operator Statoil-Hydro handles these challenges, and how it will ensure that enough competent people are available at all times to run the facility and respond immediately to disruptions or serious incidents.”

Mr Anvik also emphasises that, while the development solution at Melkøya presents challenges, many factors make it safer to operate production from land than an offshore installation. Personnel are generally more exposed on the latter, for instance.

Ormen Lange is regarded as one of Norway’s most complex offshore developments. Deep water, low temperatures and diffi cult seabed conditions also demanded a number of technological innovations to ensure safe transport of the unprocessed wellstream to land.

“Unlike Melkøya, the Nyhamna plant is spread over a large area,” notes Mr Anvik. “The process is not particularly complex compared with other landbased facilities.”

However, he notes that the many gas leaks from this plant during the start-up phase have worried both the industry and the regulators.

These events underline the need to manage in accordance with the precautionary principle. Investigations into several serious incidents at Nyhamna show that this has not been adequately achieved, Mr Anvik says.

“A case in point was provided by a bad odour from a container, which was initially attributed without any form of checking to the decay of sump water.

“Subsequent investigation established that the stench derived from toxic hydrogen sulphide. It transpired that no risk assessment had been made of the container’s possible contents, so nothing was done to determine whether the smell indicated any form of health hazard for personnel.”

During 2007, the PSA also monitored the transfer of the Ormen Lange operatorship from developer Norsk Hydro to Shell for the production phase.  “We feel this hand-over went very well,” Mr Anvik comments. “We’ve observed a well-managed transfer of experience and the build-up of necessary expertise at Shell throughout the process.”