Alcatel Submarine Networks, Nexans Win Johan Castberg PRM Work

Equinor has awarded Alcatel Submarine Networks, part of Nokia, a contract for permanent reservoir monitoring (PRM), which in turn has signed a letter of intent with Nexans Norway for delivery of subsea cable.

“PRM is a central element of the digital strategy for Johan Castberg and will be an important tool in improving the Johan Castberg recovery rate,” says Johan Castberg project director Knut Gjertsen.

The technology is developed in Norway, and the contract is awarded by exercising an option in the framework agreement on PRM that Equinor entered into with Alcatel when signing a corresponding contract for the North Sea Johan Sverdrup field in January this year.

Johan Castberg and Johan Sverdrup will share the PRM project management, leading to both synergies and savings. Johan Sverdrup and Johan Castberg are the first fields in the world to install this tool before production start.

Nexans Norway is a subcontractor to ASN on the Johan Castberg PRM project. They will manufacture the backbone cable network and inter-station cable at their facilities in Rognan, Norway. The supply will include more than 200 kilometers of subsea cable.

Seismic stations will be incorporated into the cables at ASN’s facility in Calais, France.

PRM implies that seismic sensors are installed permanently on the seabed, providing better images of reservoir changes at a more frequent rate. Both the amount and not least the quality of the information generated from this system will be central in Equinor’s plans for use of digital technology at the Johan Castberg field. This kind of data has a large potential in relation to visualisation, modelling and gradually also predictive analyses.

“More than 200 kilometers of fibre-optic seismic cables and 3700 sensors will be spread on the seabed at the Johan Castberg field. The cables will start sending images before the field starts up in 2022, providing a basis and information about the reservoirs before production start. This will increase the well placement precision and help “control” production and injection,” says Benedicte Nordang, subsea manager for Johan Castberg.

Estimated recoverable reserves for Johan Castberg is 450-650 million barrels. Planned start-up is 2022.

The Johan Castberg partnership consists of Equinor (operator 50%), Eni Norge (30%) and Petoro (20%).