Norway: Exploration and development activities began in the southern part of the Norwegian Continental Shelf in the 1960s. Subsea developments started out as tie backs to existing platforms, which is still the case for smaller developments. However, dedicated floating units (FPSO, semi, etc.) as hosts have become more prevalent for new and stand-alone developments and are solutions for greater water depths. For gas fields, "subsea to shore" developments have become attractive. Such is the case with the StatoilHydro Ormen Lange, which utilizes this solution in 2,625 to 3,280 ft (800 to 1,000 m) water depth and 75 miles (120 km) from shore.
Due to maturity of the region, many operators have been focusing their resources on increasing recovery rates from existing fields and implemented subsea tie backs for marginal new fields to existing platforms and floating facilities. Subsea separation, boosting and water-injection techniques are also becoming more widely adopted to increase field recovery rates. FMC is providing leading technology in this area and manufactured the first commercial application of a full-scale subsea separation system for StatoilHydro in June 2007, bringing the Tordis field's recovery factor from 49% to 55%.
UK: The United Kingdom subsea region can be segmented into four distinct geographical areas. First,southern shallow-water sector, is predominantly natural gas, with water depth ranging from 30 to 75 m (100 to 250 ft). Second, Central North Sea, comprising of reserves of both oil and natural gas, with water depth between 75 and 200 m (250 to 400 ft). The third area, Northern North Sea, encompasses harsh environments with water depth over 200 m (550 ft). Finally the fourth, West of Shetland which is the ‘Atlantic Margin’; harsh environment with very strong subsea currents and water depths ranging from 180 m to 1300m.
The majority of North Sea developments are small subsea tie-backs to fixed platforms or FPSO units. FMC Technologies introduced the EHXT to the market in 2004 and has significantly grown FMC's customer base including Centrica Upstream Energy; CNR; EnQuest; Eon Ruhrgas; Premier Oil; Fairfield Energy; Talisman Energy and Total UK. In the ‘Atlantic Margin’ West of Shetland FMC has secured the first deeper water subsea system for Total UK’s ’Laggan-Tormore’ development in 600m. This subsea system comprises of: two six slot template manifold systems; two satellite well systems; eight tree systems; the production controls system and flowline connection systems.