The Longest Subsea Pipeline In The World, Langeled
Route Of The Longest Undersea Pipeline In The World
The Langeled pipeline is the world's longest large diameter offshore pipeline. It runs from Nyhamna, Norway, to Easington in the UK. It is 1,166 kilometers in length and consists of 44 and 42 inch diameter pipe.
The Langeled pipeline is owned by the following companies: Norsk Hydro, Gassco, Petoro, Statoil, Shell, BP, ExxonMobil and ConocoPhillips. Norsk Hydro was in charge of the development and construction of the world's longest subsea pipeline. In 2006 operations were handed over to Gassco. It carries gas from the Ormen Lange gas field off of Norway. The gas is treated and readied for transport at a station on shore in Nyhamma Norway.
A Major Engineering Challenge
Over 2500 years ago the Chinese used hollow bamboo to create pipes that transported natural gas from shallow wells a short distance to where it was used as fuel for a flame that burned under pans and dehydrated seawater for salt. The world has come a long way since then. Imagine an undersea world with subzero temperatures, with hills, deep valleys and boulders the size of homes and laying a large pipeline across it.
The Norwegian trench is over 385 meters deep along the path of the Langeled pipeline. Engineers had to overcome many challenges to begin installing a pipeline over this undersea terrain. Before any pipe was laid for the Langeled pipeline, barges carried rock and rubble which was dumped to level valleys and smooth a path over large boulders.
When pipe laying began on the world's longest subsea pipeline in 2005, the pipe laying ship Acergy Piper was recomissioned for the task and outfitted to lay the large diameter pipe.
The pipe laying Acergy Piper completed the majority of the work on the Langeled pipeline, or over 980 km of the 1166 km, with the pipe laying ships Solitaire (Allseas) and the Saipem 7000 (Saipem) completing the rest.
On the Acergy Piper alone over 3 million man hours of labor were completed with no lost time accidents. The ship is like a floating pipe factory. A complex system of tensioners and restraints allows the pipe sections to be safely welded while the rest of the entire string dangles down toward the ocean floor. Joints of pipe are added one by one, day after a day until the entire distance has been covered. The Langeled pipeline required the welding of 96,600 individual pipe sections. Some sections were welded on land.
Once the pipeline was completed special "pigs" were used to remove the seawater from the line. Pigs are "squeegie" like devices that are placed in the pipeline at one end and forced by pressure to the other, pushing out water and debris along the way and cleaning the walls of the pipeline. Anti corrosion chemicals may be applied between a series of pigs which are pumped together.
Photo From BBC.
The Acergy Piper can lay up to 5 km of undersea pipeline a day. The ship has since been sold to Saipem of Portugal
Langeled To Supply Much Of UK's Gas
Since the UK's own offshore fields have declined in the past two decades it became evident that the country would need to import much of the natural gas it needed. The Langeled pipeline will supply over twenty percent of the UK's gas. The longest subsea pipeline in the world is capable of carrying an incredible 25.5 billion cubic meters (bcm) of natural gas per year.
The Langeled pipeline is not the longest pipeline in the world, but it is the world's longest subsea pipeline of it's size.
When completed The Eastern Siberia - Pacific Ocean, Pipeline operated by the Russian oil company Yukos will be the longest large diameter pipeline in the world. This pipeline will carry Russian crude to market and will be over 4700 km long. Expected completion is in 2014.