Troll A platform
The Sea Troll is the largest gas production platform in the North Sea and also the largest oil platform in the world. It is used for production of natural gas from the Troll gas field in the Norwegian Exclusive Economic Zone of the North Sea.
Troll gas field
The Troll gas field is located approximately 100 km off the Norwegian coast, west of Bergen. 1979 natural gas was first discovered there. The gas field is considered the largest natural gas discovery in the North Sea and will supply natural gas for 50 to 70 years. From here, the natural gas produced is exported by pipeline ( pipeline ) in different countries in Europe. The Troll gas field is operated by the Norwegian state oil company Statoil. It was developed under the direction of the Shell Group. The plans lasted until 1990, the construction of the oil rig and the development of the gas field were made 1992 until 1995.
Drilling rig
Began in 1992, the Norwegian company Aker Kværner with the construction of the oil rig Condeep construction. Set up in 1993 a 36 meter high Grunddom in the dry dock of Stavanger was built in the summer of 1994, then from the four per 343 meter high concrete pillars were built in the Norwegian fjord Vats. It was a special procedure of the Austrian company Gleitbau used that allowed by means of a sliding form construction in a train and was able to keep the construction time low.
Also on land, 22,500 tons of heavy work platform was composed of different modules so that in January 1995, could begin "Rendezvous " from the drilling rig base and work platform. For this, the ballast tanks in the base as well as the total column were flooded and lowered in the fjord, so that the four pillars sticking only 6.5 meters above the water level. Then floating on pontoons working platform of tugs could be pulled over the pillars.
In a similar maneuver a sister platform of the Sea Troll - the Sleipner A - came there during the flooding of the columns in an accident. On the basis of the pressure conditions imploded the columns and sank to the seabed. The impact on the seabed could be registered as an earthquake of magnitude 3.
After installation, the entire rig was raised to the extent that they towered 230 meters above sea level, in May 1995 could be pulled to their destination. Ten tractor with a total of 130,000 horsepower required ten days to haul the rig at a speed of 1.7 knots for 170 nautical miles away Troll gas field. With this transport, the platform is considered the largest and heaviest ever moved by man-made structure.
After transport the Sea Troll was lowered to the seabed. Within days, the rig sank by its own weight about nine meters into the soft seabed one. Finally there is the work platform about 30 meters above the sea level. At their destination is a floating hotel platform over a gangway to the Sea Troll was connected. This is not anchored, but it is held with computer-controlled motors to their exact position.
When the Sea Troll began its work, 40 drill pipe were first driven to a depth of 1200 meters in the Troll gas field. In the late summer of 1995 began with the laying of the pipelines on the seabed, so that in May 1996, the gas production could be included. The gas pipeline is managed by a diagonal tunnel from the 250 -meter-deep seabed up to the treatment plant on the coast by the Norwegian coastal mountains. Work on this tunnel were already started at the beginning of construction of the Sea Troll and proved to be extremely difficult.
Specifications
- Start of construction: 1992
- Completion: 1995
- Height: 472 m ( from the bottom of the base to the tip of the gas flare mast )
- Water depth at the location: 303 m
- Displacement: 1 million tons
- Project costs 4.75 billion U.S. dollars
- Power supply: HVDC Troll
Trivia
The American TV channel Discovery Channel has a documentary about the construction, transport and commissioning under the title - produced " gas giant in the North Sea The Sea Troll ".
Deepest underwater concert
On 3 October 2006 took the base of the platform - 303 meters below the surface - a concert by the British- Georgian singer Katie Melua instead. With great safety precautions they played about 30 minutes before one of only 40 people counting audience. The concert was entered as the deepest concert that ever took place in the Guinness Book of World Records. In May 2007, the DVD documentation Concert Under The Sea appeared, which reports on the preparations and the concert.