Statoil begins installation work
on Asgard subsea compression modules

June 9, 2015   + + +  Statoil ASA has started installation of the modules comprising the subsea gas compression plant for Asgard field in the Norwegian Sea. A total of 22 modules will be installed and connected, forming two 1,500-tonne compressor trains. The modules over the summer will be laid in place in a large subsea frame that was installed 2 years ago (OGJ Online, June 13, 2013). The newly rebuilt North Sea Giant vessel is carrying out installation work.

The modules comprising plant vary in size, with the smallest installed via the vessel’s “moonpool,” a large opening in the bottom of the hull through which modules weighing as much as 70 tonnes are lowered.

The larger modules are installed by the North Sea Giant’s crane system, which has been modified to incorporate a special handling system. The system is designed to carry up to 420 tonnes and operate in up to 9-m-high waves. Each module is guided into place with a remotely operate underwater vehicle and cables.

All modules are provisionally stored at Vestbase in Kristiansund, Norway, where they’re shipped out following commissioning and testing in Egersund. Statoil notes that the installation sequence has been planned so that start-up work can be carried out on the first compressor train while installation work continues on modules for the second train.

Conducted in 300 m of water, the project will result in additional production of 282 million bbl from the field, the company says. Last year, a contract was given to Technip SA for intervention services on the compression stations (OGJ Online, Feb. 11, 2014).

Source: Statoil - www.statoil.com
Published by Oil & Gas Journal

First Åsgard subsea compression kit heads to seafloor

June 09, 2015   + + +  The North Sea Giant vessel has begun offshore installation of the modules for the Åsgard subsea gas compression project in the Norwegian Sea. This is designed to extract a further 282 MMbbl from the Åsgard field.

According to operator Statoil, 22 modules will be installed and connected at a water depth of 300 m (984 ft) to form two identical compressor trains, each weighing 1,500 metric tons (1,653 tons). They will be housed in a large subsea frame installed on the seafloor in summer 2013. All the modules are being shipped from Vestbase in Kristiansund, having undergone commissioning and testing in Egersund. They vary in size. The smallest modules – up to a maximum weight of 70 metric tons (77 tons) – are being lowered through the vessel’s moonpool.

A special handling system makes the installation work more efficient on the Åsgard field. (Photo courtesy Statoil)

Larger modules will be installed using the ship’s crane handling system which can lift loads of up to 420 metric tons (463 tons) and which can operate in waves up to 9 m (30 ft) high. In this case, the modules are guided into position subsea via an ROV and cables.

Installation sequence has been planned to allow start-up work to be performed on the first compressor train while installation of modules for train 2 continues.

Source Statoil - www.statoil.com
Published by Offshore Magazine