Ormen Lange, Europe's most ambitious subsea gas development, is progressing well. Currently the project's Norway-UK pipeline network is 7% laid, reported Norsk Hydro's Tom Rotger last week during ONS Stavanger. The elongated Ormen Lange structure is being developed in a first phase through four subsea templates grouping together 24 welheads. Gas will be piped to a new processing plant at Nyhamma, a short distance to the east, before being routed southwest 1,200-km to Easington, eastern England, via the world's longest subsea gas trunkline, called Langeled.
Hydro is operating the overall project in its development phase. Norske Shell will take over for the operational phase and will also manage well delivery and subsurface systems. Gassco will operate the Langeled line during the operational phase. So far this year, NKr8 billion has been spent in 2003 money, Rotger said, with NKr20 billion to follow in 2005. First-phase investments overall should total NKr67 billion.
The process plant at Nyhamma will handle up to 70 MMcm/d, similar in scope to the Troll gas reception plant at Kollsnes. Aker Kvaerner completed front-end engineering design for this facility in January. Most of Ormen Lange's subsea contracts have been awarded, Rotger added, except for dredging. FMC Kongsberg started fabrication of the 1,000 t subsea templates in May, which are due to be completed and installed next year. Heerema is fabricating the manifolds in Tonsberg, and these will be set in place by the heavy lift bargeThialf.
Six subsea pipelines will be laid. The section to Nyhamma will be the shortest, at 33 km; the deepest point (up to 26 km out from the field) will be 1,000 m. Once installed, the lines will be protected by a total of 2.8 million tonnes of rock dumped by Van Oord Offshore. Currently, dumping work is taking place close to the pipeline landfall in Norway. Rotger pointed out that the seabed area along the main trunkline route, "being very up and down and hilly, with boulders," needed plenty of rock, both to stabilize the pipelines and to avoid free-spans developing. To limit the amount of rock dumping required, and ensure correct positioning of the pipe, Nexans will undertake pre-dredging with its Spider tool.
Saipem'sS7000 barge will lay the main trunklines in 2006. Around 1 million tonnes of steel has been ordered to produce around 100,000 pipe joints, with 375,000 cu m of concrete coating. To date, 17,000 pipe sections have been received from Japan.
Smedvig has been awarded a NKr1.2 billion development drilling contract, which involves pre-drilling of eight production wells using its dual-derrick DP drillship theWest Navigator. Drilling should start mid-summer next year, after the subsea structures are in place.