Snøhvit
Snøhvit ( Snow White German ), also Snøhvitfeltet, is the fifth largest Norwegian gas field - operated by Statoil Group. It actually consists of three individual fields Snøhvit, Albatross and Askeladd, but they are become part of a common development plan. The deposits were discovered in 1984 and located about 140 kilometers northwest of Hammerfest on the Norwegian continental shelf in the Barents Sea.
Overview
It is estimated that the field contains recoverable quantities of natural gas in the order of about 160 billion Sm ³ and with a carbon dioxide content of 5-8%, to be obtained for the production of liquefied natural gas. It is assumed an annual volume of 5.75 billion cubic meters of LNG, plus 747,000 tons of gas condensate and 247,000 tonnes of LPG. Also available is a thin oil zone. The reservoirs are located in sandstones of the Lower and Middle Jurassic.
The heart of the system, a 9 × 154 × 54 m wide and 10,000 -ton barge, which is equipped with a 25,000 -ton process for gas liquefaction plant was installed on the island of Melkøya near Hammerfest. She left in June 2005 their shipyard in Puerto Real, Cadiz in southwest Spain and was transported by semi- submersible ship Blue Marlin on their site, where they arrived in late September and was installed there until the summer of 2006.
Through a 143 km long and 68 cm in diameter subsea pipeline consisting of various liquid natural gas condensate phases flow is taken to the processing plant to the island Melkøya. The pipeline is referred to as the longest pipeline multiphase ( multi-phase pipeline ) in the world. On Melkøya the phases are separated and processed. There you will find the controls and a refrigeration system, with the natural gas produced is cooled. This is the first gas production facility in Norway, which does not need any production platforms on the sea surface.
Commissioning
In the fall of 2007, the plant was put into operation. After a few weeks the plant was shut down due to technical teething problems. The operation was resumed with effect from 25 January 2008 and now has 100 % capacity (as at March 2009).
The heart of the system was designed and supplied by Linde. The refrigeration cycles for cooling of the gas were successfully optimized in terms of availability and energy consumption.
The costs were estimated initially with crowns 51 billion ( 6 billion euros ). The actual costs are now estimated at 60 billion crowns (February 2008). These high amounts of investment will pay for itself but in a few years due to long-term contracts.
Environment
The plant is a prime example of environmental protection, as the natural gas contained in the CO2 is not emitted to the atmosphere as usual, but stored underground. Continuous emissions are caused only by the highly efficient gas turbines for power generation, but the burn purified natural gas relatively environmentally friendly with minimal NOx production. Toxic substances such as benzene or mercury are removed in the process and handled safely. Gas flaring is not provided in normal operation, but can occur in case of malfunctions. By flaring the gas to January 2008 1 million tons of CO2 were released. The resulting also emitted 2,200 tons of soot had an additional greenhouse effects as 3.5 million tonnes of CO2.
See also: CO ₂ capture and storage