British Prime Minister Tony Blair had only positive things to say about Norwegian technology during the official opening of the Langeled gas pipeline in October 2006. This engineering wonder combines the development of Ormen Lange, the largest industrial undertaking in Norwegian history, with Langeled, the world’s longest gas pipeline system. When finished, the project will supply 20 percent of the UK’s gas demand for the next four decades.
From the Sleipner platform in the Norwegian North Sea to Easington in the United Kingdom, gas is already flowing to warm an estimated 10 million Brits for the next 40 years. Langeled pipeline has a length of 1,200 kilometres, with over 600 kilometres already in use. Ormen Lange is located in the North Sea off the coast of Norway and will be the second-largest gas field on the Norwegian continental shelf (NCS) and a major new gas source for Europe from the fall of 2007.
Partners in the Ormen Lange field are Hydro, Shell, Petoro, Statoil, Dong and ExxonMobil, with Hydro serving as the operator in the development and construction phase. Shell will take over as operator after Ormen Lange comes onstream and will also be responsible for the drilling of the production wells.
Langeled is the world’s longest gas pipeline system – at a length of 1,200 kilometres in the North Sea.
Underwater Miracles at Ormen Lange
From two subsea stations at a depth of 850 metres, two 30-inch pipelines will transport the wellstream to the onshore plant at Nyhamna on the coast of mid-Norway for processing. Underwater construction was demanding with pipelines laid across an extremely irregular seabed with boulders and slide blocks up to 60 metres in height. The Nexans Spider – a newly developed, remote-controlled excavator, was instrumental in preparing the seabed for the passage of the pipelines over these steep slopes far below the surface of the sea, dredging the seafloor and removing hard soils in tough terrain with slopes of more than 30 degrees.
Several of the world’s largest pipelaying vessels were involved in installing the Ormen Lange gas pipelines between the gas field and Nyhamna. In early September 2006, the second gas pipeline was connected to the subsea plant on the Ormen Lange field in the Norwegian Sea, meaning that 600 kilometres of gas production and anti-freeze pipeline as well as a support system control cable have now been laid on one the world’s most demanding seabed areas.
In October 2006, the subsea facility on the Ormen Lange field was then connected up to the pipelines that will transport the gas to the processing plant at Nyhamna. This marked the culmination of several years of planning, detailed mapping and extensive work on the seabed between the field and the Nyhamna gas plant in Møre and Romsdal.
The Technology of Tomorrow
A number of Norwegian companies have provided technological support and expertise as part of this historic project. These include survey support from Kongsberg Maritime, who together with the Norwegian Underwater Institute undertook seabed surveying using the autonomous underwater vehicle HUGIN, able to work at depths of up to 4,500 metres. After surveying, Kongsberg position vessels and remotely controlled vehicles were used to provide a highly reliable reference system for the underwater terrain.
Nexans, a worldwide leader in the cable industry, supplied 250 kilometres of umbilicals to operate the subsea production systems, as well as the first 420 kV XLPE submarine power cable to be used to supply the gas processing plant at Aukra. Nexans has also recently purchased the C/S Bourbon Skagerrak (which has now been renamed the C/S Nexans Skaggerak) – one of the world’s most advanced cable-laying vessels and instrumental in the Ormen Lange/Langerud project
Where No Engineers Have Gone Before
Aker Kværner Subsea has been selected by Hydro to engineer, procure and construct a full-size subsea compression station pilot for Ormen Lange – a world’s first. With a potential contract value of over $140 million, this subsea compression pilot at 900 metres below the surface can represent a cost-effective alternative to the offshore platform originally planned.
Currently, Aker Kværner is developing the onshore process facility for Ormen Lange at Nyhanna. The Norwegian company Vetco Aibel is also instrumental in the development of the Nyhanna facility, having been engaged by Hydro to undertake nearly $100 million worth of construction activities.
The Longest in the World
Langeled is the world’s longest subsea pipeline and has raised the bar in the world of oil and gas engineering. The construction of the pipeline has required approximately one million tonnes of steel and engaged a large part of the world’s pipeline production and laying resources. The northern section of the pipeline has a diameter of 42 inches, with the section from Sleipner to Easington sporting a diameter of 44 inches.
The massive lay barge Acergy Piper installed most of the 1,200-km long pipeline between Nyhamna in Norway and Easington in the UK. With six welding stations along the length of the ship, pipes were welded together, a protective coating added, and then an ultrasound check of the welds made before the pipeline was laid on the sea floor at a speed of up to five kilometres daily. The pipelaying activity was completed in early October 2006.
The C/S Nexans Skaggerak was instrumental in laying cables related to the Ormen
© Ole Magus Grønli/Nexans
The participating interests in Langeled Joint Venture are Hydro, Petoro, Statoil, Dong, ExxonMobil, ConocoPhillips and Gassco. Hydro had been the lead operator for Langeled in the development and construction phase, with the wholly state-owned limited company Gassco taking over operation of Langeled from September 1, 2006. Hydro and Statoil’s cooperative effort during the development phase was both a technological and financial success, with final costs estimated to be approximately $500 million less than originally planned.
Not yet satisfied, the Norwegians are still looking for opportunities. Another potential pipeline may be in the works if Statoil is able to realize 320 million cubic metres of gas in the new Troll reserves. This is excellent timing as well, with European demand for gas expected to increase dramatically over the next 25 years. So, enjoy your next cup of tea in the United Kingdom, and think of the Norwegians who may have helped warm up that tea for you.