GALLERY: Island Offshore starts Johan Castberg anchor system job

Project & Tenders

Island Victory, Island Offshore’s installation vessel, has started working on an enormous anchor system being deployed at Equinor’s Johan Castberg field in the Barents Sea.

Source: Island Offshore

Island Offshore said on Tuesday that this was one of the most comprehensive anchoring projects globally in 2020.

This work is conducted in preparation for the arrival of floating production storage and offloading unit (FPSO), which will be processing and storing oil from the 30 wells on the seabed when the production starts in 2022.

The company was hired by Ocean Installer and end customer Equinor for the project. Ocean Installer won a contract for mooring installation, tow out, and hook-up of the Johan Castberg FPSO in December 2018.

The Captain on board the Island Victory said: “Weight and logistics in this project have called for good preparations, and we have spent much time planning together with client and customer. Each suction anchor weighs between 90 and 105 tonnes and is between 13 and 17 metres high. Island Victory loads five of these giants on board in one go.

84mm versus 170mm chain; Source: Island Offshore
84mm versus 170mm chain; Source: Island Offshore

In addition, the weight of the 170mm chain is 600 kilograms per metre. Compared to a regular offshore anchor handling chain of 84mm the weight of the chain is not only double – it is four times as heavy!

On the first trip to Johan Castberg, five anchors and five anchor chains were loaded onboard the vessel. The objective is to set two anchors a day, as well as attaching anchor chains to each anchor.

Three trips back and forth to Polarbase in Hammerfest are planned to get all anchors loaded. When all fifteen anchors are embedded into the sea floor, the installation of wire and top chain can start. This is placed on the seabed ready for the FPSO to hook up.

In addition to setting anchors and lines, the seabed floor conditions have to be documented as well. Each metre of chain placed on the seabed is filmed by two work ROVs operated by C-Innovation.

Also, as a preventive measure regarding COVID-19, all parties agreed to reduce crew for this job, to avoid cabin sharing. The project operation team from Ocean Installer and Equinor amounts to 67 persons in addition to the vessel crew.

Before commencing the job at Johan Castberg, Island Victory was engaged by the same client and end customer at Askeladd where large subsea manifolds were deployed and extensive survey and subsea work were done.

This project marked the first record lift using Island Victory’s offshore crane – two manifolds of 175.2 tonnes each was lifted and placed on the seabed.

According to Island Offshore, Island Victory will complete the Johan Castberg work at the beginning of July and will then start mobilizing for her next job in the Gulf of Mexico, starting in August.

To remind, the last two modules for Equinor’s Johan Castberg FPSO turret mooring system sailed away from Dubai to Singapore in late April.

The modules were heading to Singapore to be integrated into the hull of the Johan Castberg FPSO, which is being built by Sembcorp Marine with Kvaerner in charge of building the topsides.