Norway Blocks 6407/2, 6506/11 & 6507/11
Landmark: North Sea’s Largest Subsea Development
Project Overview
- Contract Award: 1996
- Sales: Kongsberg, Norway
- Fab. Trees: Dunfermline, U.K.
- Fab. Controls: Kongsberg, Norway
- Service Base: Bergen, Norway
- Host Type: FPS-Semi and FPSO
- Contract Type: EPC
Project Characteristics
- No. Trees: 59
- Water Depth: 300 m (980 ft)
- Tree Type: Horizontal
- Tree Pressure: 10,000 psi
- Tree Bore Size: 7"x2"
- Hydrocarbon: Oil/Gas
Project Ownership
- Petoro 35%
- StatoilHydro 35%
- ENI 8%
- Total 8%
- ExxonMobil 7%
- Fortum 7%
Scope of Work
- Fifty-nine (59) horizontal 7"x2" 10,000 psi subsea trees
- UWD-15 subsea wellheads
- Seventeen (17) HOST® templates with manifolds and control distribution system
- Workover risers and control systems
- Subsea electro-hydraulic and topside control systems
- Provision of 125 km (77 miles) of subsea control umbilical
- Universal tie-in system (UTIS®) rental tools
- Intervention control system
- System integration testing, installation assistance, service and maintenance
Comments
North Sea’s largest subsea development at the time of completion, Åsgard lies on the Haltenbank in the Norwegian Sea, about 200 km (120 miles) from mid- Norway and 50 km (30 miles) south of StatoilHydro’s Heidrun Field. Åsgard is comprised of the Midgard, Smorbukk and Smorbukk South deposits, which were discovered in 1981, 1984 and 1985, respectively. Water depths vary from 240 to 300 m (790 to 980 ft). Midgard straddles Blocks 6507/11 and 6407/2, while the other two (2) deposits lie in Block 6506/11.
The development consists of a mono-hull unit (Åsgard A), for oil and condensate production with the world’s largest floating gas semi-submersible platform (Åsgard B). The other installation for development of the fields are Åsgard C (a storage ship) and the necessary subsea production installations. The subsea systems include seventeen (17) templates and fifty-nine (59) wells. The project was executed as an EPC contract under StatoilHydro's and Saga’s integrated team philosophy. All phases of the project (drilling, installation, operation and maintenance) are designed for diverless operation. The HOST® template design is used for all templates. HOST® introduced a new concept, where the template is assembled of modules (on deck or subsea). The modules are moonpool deployable. Pull-in and connection are performed in one operation with the new UTIS® tie-in tool.
Some of the trees from Åsgard were used on several other Statoil fields to accelerate their development. This was possible through StatoilHydro's practice of standardized subsea system equipment. The Åsgard Field will produce 420 bcf of natural gas per year (plateau), as well as 200,000 bopd and 94,000 bpd of condensate.