Fibre-optic reservoir monitoring – a digital enabler for improved recovery (illustration: Statoil)

Statoil has awarded a contract to Alcatel Submarine Networks for Permanent reservoir monitoring (PRM) on the Johan Sverdrup field. The seismic technology – a potential digital enabler for the field – will be a key contributor to delivering on Johan Sverdrup’s 70% recovery ambition.

“Johan Sverdrup will make up a significant part of Norwegian oil production going forward and has a lifespan of over 50 years, so it is important that we work systematically to maximise value and ensure as high a recovery factor as possible from the field. PRM plays an important role in this, and will be a key tool in realising the 70% recovery ambition on Johan Sverdrup,” says Kjetel Digre, project director for Johan Sverdrup.

With 380 kilometres of fibre-optic seismic cables installed on the seabed and more than 6500 acoustic sensors covering an area of more than 120 square kilometres, Johan Sverdrup will have one of the largest fibre-optic seismic systems of its kind.

For the first time on any field on the Norwegian continental shelf (NCS), the seismic technology will be in place ready to optimise production in time for start-up. The seismic cables will be installed on the seabed of Johan Sverdrup during 2019.

With PRM, seismic sensors are permanently embedded into the seabed which enables more frequent and much improved seismic images of changes in the reservoir. The system on Johan Sverdrup will use optical fiber technology which allows for continuous recording of changes in the subsurface.

The significant data generated by this system is considered a key input to enable Statoil to deliver on its digital roadmap for the field.

“We see great potential with PRM on Johan Sverdrup in terms of improved visualisation, modelling and eventually also predictive analytics,” says Eli Eikje, head of Petroleum technology for Johan Sverdrup. “This should give us improved precision in our well locations, help us better control production and injection, but should also contribute with information about the condition of wells and subsea infrastructure – which is critical for a field with a 50-year lifespan,” continues Eikje.

With a recovery ambition of 70%, Johan Sverdrup will become one of the fields in the world with the highest recovery factor. Statistics from the Norwegian Petroleum Directorate shows that average recovery from the NCS is at 46%.

“The NCS is world leading in terms of resource recovery. Johan Sverdrup is drawing on the experiences of giants like Statfjord, Gullfaks, Oseberg, Snorre og Troll. And PRM will lay the foundation for future recovery initiatives such as infill wells, water and gas injection, but also in the area of digitalisation,” says Digre.

The frame agreement with Alcatel Submarine Networks also includes opportunities for future collaboration around technology development and solutions to further maximise the potential from the PRM system.

The frame agreement also includes an option to extend seismic coverage to include the southernmost part of the Johan Sverdrup field.

The decision to install PRM at Johan Sverdrup meets an authority requirement set in the Plan for Development and Operation (PDO).

Statoil has previous experience with PRM on the Snorre and Grane fields, also on the NCS.

Tags: Alcatel Submarine Networks, Statoil