Nokia’s ASN will install permanent reservoir monitoring (PRM) at Norway’s supergiant field in time for production start-up in 2019
Progress on Norway’s supergiant Johan Sverdrup development is continuing, with Statoil last week signing the project’s first new contract award of 2018.
Under the new award from the Norwegian NOC, Alcatel Submarine Networks (ASN) will install permanent reservoir monitoring (PRM) at the field, in time for production start-up in late 2019. Statoil says that the system – also known as 4D seismic for its ability to monitor changes in fluid flow and reservoir structure over time – will be a key factor in successfully achieving its 70% recovery target.
Using a permanent array embedded into the seabed allows the operator to obtain seismic data much more frequently and provides a more detailed view of any changes in the reservoir, in this case offering a continuous record of change in the subsurface.
In addition to aiding its recovery target, the use of PRM also meets requirements set out by Norwegian regulator NPD in its approval of the field’s plan for development and operation (PDO).
“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,” said project director for Johan Sverdrup Kjetel Digre.
The contract will see ASN install 380 km of fibre-optic cables on the seabed, using over 6,500 acoustic sensors to monitor more than 120 square km of the field. Statoil says this will represent one of the largest fibre-optic seismic systems of its kind.
The frame agreement with ASN – part of the Nokia telecoms group – also includes an option to extend seismic coverage to include the southernmost part of the Johan Sverdrup field, and potential opportunities for future collaboration on technology development.
ASN appears to have acquired the PRM technology via its acquisition of Norwegian firm Optoplan from CGG Group in 2014. The Trondheim-based company developed Optowave, one of the leading 4D seismic and PRM technologies in the North Sea, and which was installed at projects such as ConocoPhillips’ Ekofisk field, in 2010.
“We see great potential with PRM on Johan Sverdrup in terms of improved visualisation, modelling and eventually also predictive analytics,” said Johan Sverdrup head of petroleum technology Eli Eikje. “This should give us improved precision in our well locations, [and] 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.”
According to Digre, the use of PRM will also inform additional recovery measures and “lay the foundation for future recovery initiatives such as infill wells, water and gas injection, but also in the area of digitalisation.”
Statoil first used 4D seismic more than 20 years ago, with a pilot programme implemented at the Oseberg field. This was later followed by a full-field use at Gullfaks, where multiple datasets acquired between 1985 and 1996 were used to infer areas with a high possibility of undrained oil.
In 2013, Statoil awarded seismic firm CGG contracts to implement PRM at its Snorre and Grane fields, under which data would be acquired at least twice a year over an initial contract period of four years.
However, the use of PRM at Johan Sverdrup will be the first time that any Norwegian Continental Shelf (NCS) development has used the technology from the start of production.