High level performance for world’s first subsea gas compression facility

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Located on the Halten Bank in the Norwegian Sea, about 200 kilometers from mid-Norway, Åsgard is a central hub and a significant oil and gas producer. It is also the first field in the world to use seabed gas compression. The decision to adopt this new technology on the Åsgard field is expected to maintain production and an increased recovery equivalent to approximately 278 million in barrels of oil when the project is realized.

A concept suitable for most large subsea gas fields, subsea compression systems provide improved energy efficiency and safety, and lower investment and operating costs when compared with using traditional platforms. When gas is produced, the pressure in the reservoir decreases and the well flow may need boosting in the form of compression. In many instances, subsea compression technology is necessary to create enough pressure for the hydrocarbons to travel up the pipelines to the receiving terminal.

Pioneering performance
Trelleborg provided high performance subsea insulation for use on the Asgard Subsea Compression Project. The innovative solution came in the form of Trelleborg’s Vikotherm™ R2 insulation material, to be used on 600 meters of piping forming part of the Åsgard subsea compression system.

Vikotherm™ subsea thermal insulation material has been successfully installed throughout the subsea oil and gas industry for over twenty years and has recently been enhanced to offer improved elasticity, as well as better process and manufacturing flexibility as the system can be applied on site, anywhere around the world. Vikotherm™ R2 was successfully launched into the market in 2012.

Across the 600m of piping, this proven solution will be applied in sizes varying from two to six inches / 50 to 300 millimeters. The pipelines will also include varying geometries - valves, transmitters and flanges – varying surfaces - super duplex, stainless steel and epoxy – and also varying applications - factory and site application.

Optimal flow assurance, without maintenance
Vikotherm™ R2subsea insulation is a practically incompressible, seawater and impact resistant solution which not only has excellent thermal insulation properties, but maximum corrosion protection too, guaranteeing

optimal flow assurance. Furthermore, it is designed to last the life of a subsea project, is maintenance-free and will never normally require replacement.

Aker Solutions’ scope of work for the subsea compression system includes a subsea compressor manifold station (SCMS), subsea compressor station (SCST) template structure, three identical compressor trains, all electrical control systems, highvoltage electrical power distribution system, topside equipment, and tooling, transport, and installation equipment.

“This project represents a quantum leap in seabed technology and is an important step towards realizing the field operator’s ambition to develop a complete subsea production site. As such, guaranteeing optimum performance and complete reliability at every turn is of paramount importance. The formation of hydrate plugs and wax build up is a real risk during operation shut downs, high performance subsea thermal insulation is required to ensure optimal flow assurance.”
Hans Leo Hals, Managing Director
of Trelleborg Offshore based in Norway