Installation of Åsgard subsea gas compression modules underway, Statoil says
STAVANGER, Norway -- The installation of the modules that collectively constitute Åsgard field's subsea gas compression system has commenced, Statoil announced Tuesday.
The technology, which will be installed at a water depth of 300 m, will facilitate the extraction of an extra 282 MMboe from the field.
According to Statoil, 22 modules will be installed and connected. These comprise two identical compressor trains weighing 1,500 tonnes each.
During the summer, this technology will be placed in the large subsea frame that was installed on the field during the summer of 2013.
The installation work is being carried out by the North Sea Giant vessel, which was rebuilt for the purpose.
The modules comprising the subsea gas compression plant vary in size. The smallest modules are being installed via the vessel's 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 tonnes can be installed in this way.
Several of the modules to be installed in the subsea plant are too large to be lowered through the ship's moonpool. Thus, the ship's crane system has been modified to incorporate a special handling system (SHS).
This lifting system is designed to carry a load of up to 420 tonnes and can operate with wave heights of up to 9 m. Each module is lowered into the sea via a crane and guided into place with a remotely operated vehicle (ROV) and cables.
"This crane system makes the installation work safer and more efficient. To ensure quality at every stage of the process, all operational crew have practiced the operations in a specially designed simulator,” project director Torstein Vinterstø said. "We have also performed a number of sea trials prior to installation."
The installation sequence has been carefully planned so that start-up work can be carried out on the first compressor train while work to install modules on train 2 continues.
The operations organization in Stjørdal, which will take over the plant once it has been completed on the project side, is closely following the installation work, which, thus far, has been carried out to a high level of quality and in accordance with the established schedule.
"I am very pleased that we have now commenced the installation work and that preparations for start up and operation are now underway," said Snorre Grande, senior V.P. for Åsgard subsea gas compression in Field Development. "The ship fitted with the new crane system will also be a good tool for us once the system becomes operational.”
