Statoil started the installation of 22 Åsgard subsea gas compression modules in the Norwegian Sea.
 |
|
Åsgard subsea compressor. |
The Åsgard field lies on the Halten Bank, about 200km off mid-Norway, and 50km south of Heidrun. Åsgard ranks among the largest developments on the Norwegian Continental Shelf, and comprising a total of 52 wells drilled through 16 seabed templates.
The modules comprise two identical compressor trains that weigh 1500-tonne each. The Norwegian giant is using innovative technology at a depth of 300m that will create an extra 282 MMboe from the Midgard and Mikkel reservoirs by placing the subsea compressors as close to the reservoirs as possible. Statoil plans on using this technology this summer, in the large subsea frame that was installed on the Åsgard field in the summer of 2013.
North Sea Shipping’s North Sea Giant subsea construction vessel, which was rebuilt specially for Åsgard, will conduct the installation work.
The modules comprising the subsea gas compression plant vary in size. The smallest modules are being installed via the vessel's so-called "moonpool," a large opening in the bottom of the hull through which the modules are lowered. Modules with a maximum weight of up to 70-tonne can be installed in this way, Statoil said.
However, several of Åsgard’s modules are too large to be lowered through the ship's moonpool, and modifications were done to the ship's crane system to incorporate a special handling system.
.jpg) |
|
Åsgard subsea compressor. |
According to Statoil, the lifting system is designed to carry a load of up to 420-tonne and can operate in up to 9m high waves. Each module is lowered into the sea via a crane and guided into place with a ROV and cables that makes installation work safer and more efficient.
Statoil has carefully planned the installation sequence so that start-up work can be carried out on the first compressor train while work to install modules on train 2 continues.
The Åsgard field comprises the Midgard, Smørbukk and Smørbukk South discoveries. Midgard straddles blocks 6507/11 and 6407/2, while the two other deposits lie in block 6506/11. Production of oil, gas, and condensate at the field began in 1999.
Åsgard marks the first time an operator is using compression on the seabed, instead of on a platform. The technology represents a quantum leap that can contribute to significant improvements both in the level of extraction and operational life of a number of gas fields, Statoil said.
The modules for Åsgard’s first compressor train began their journey from Norway to Kristiansund in December 2014.
Statoil is the operator of Åsgard with 34.57% interest. Partners include Petoro (35.69%), Eni (14.82%), Total (7.68%), and ExxonMobil (7.24%).
Also today, Statoil announced its third discovery in the Aasta Hansteen area in three months. The natural gas find at the Gymir prospect, that proved a gross 70m gas column in the Nise Formation with good reservoir qualities. It is estimated to have volumes in the range of 6-19 MMboe.
Read more:
Subscribe
