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Title: Danish line insulated against hydrate formation

Journal Article · · Oil Gas J.; (United States)
OSTI ID:5847013

Development of Danish North Sea hydrocarbon resources includes the 17-km Rolf pipeline installed in 1985. This one consists of an insulated 8-in. two-phase flow product line with a 3-in. piggyback gas lift line. A practical solution to design of this insulated pipeline, including the small diameter, piggyback injection line was corrosion coating of fusion bonded epoxy (FBE) and polyethylene (PE) sleeve pipe. The insulation design prevents hydrate formation under the most conservative flow regime during gas lift production. Also, the required minimum flow rate during the initial natural lift period is well below the value anticipiated at the initiation of gas lift. The weight coating design ensures stability on the seabed during the summer months only; thus trenching was required during the same installation season. Installation of insulated flowlines serving marginal fields is a significant feature of North Sea hydrocarbon development projects. The Skjold field is connected to Gorm by a 6-in., two-phase-flow line. The 11-km line was installed in 1982 as the first insulated pipeline in the North Sea. The Rolf field, located 17 km west of Gorm, went on stream Jan. 2. The development includes an unmanned wellhead platform and an insulated, two-phase-flow pipeline to the Gorm E riser platform. After separation on the Gorm C process platform, the oil and condensate are transported to shore through the 20-in. oil pipeline, and the natural gas is piped to Tyra for transmission through the 30-in. gas pipeline. Oil production at Rolf is assisted by the injection of lift gas, transported from Gorm through a 3-in. pipeline, installed piggyback on the insulated 8-in. product line. The seabed is smooth and sandy, the water depth varying between 33.7 m (110.5 ft) at Rolf and 39.1 m (128 ft) at Gorm.

Research Organization:
Maersk Oil and Gas A/S
OSTI ID:
5847013
Journal Information:
Oil Gas J.; (United States), Vol. 84:16
Country of Publication:
United States
Language:
English