Brownfield Boost: Vigdis Gets a Subsea (Pump) Lift

The Vigdis subsea field in the North Sea has produced oil via the Snorre field for 24 years, and when it came on stream in 1997, it was projected to produce 200 million barrels.To date, according to Equinor, it has produced twice that amount, and courtesy of installation of a new subsea pumping system, that total is anticipated to reach or surpass the 475 millon barrel mark, as a pump on the seabed will give the Vigdis field a boost that increases production by around 16 million barrels.

“Increasing production from existing fields is important for value creation on the Norwegian continental shelf," said Asbjørn Løve, vice president for the Snorre field. "We have further developed Vigdis in several phases over several years."

In December 2018 the license partners – Petoro, Vår Energi, Idemitsu and Wintershall Dea as well as Equinor – decided to invest around $158m in the Vigdis Boosting project, a project for improved oil recovery (IOR), which includes a multiphase boosting station increasing production from existing wells. This pump came on stream in May 2021.

Connected to the existing pipeline between Vigdis and Snorre A, the boosting station helps bring the well stream from the subsea field up to the platform. In addition, it reduces wellhead pressure, which also leads to higher oil recovery from the wells.

“Advanced processing equipment on the seabed is key in our subsea factory strategy, aiming to increase and extend production from existing fields and contribute to new development solutions on new fields,” said Geir Tungesvik, SVP for project development in Equinor.

Subsea pumps have proven particularly strategic to deep-water fields with long distances between subsea facilities and platforms.

The contract for supplying the boosting system, including the template and trawl protection, was awarded to OneSubsea, with engineering in Bergen and assembly at Horsøy near Bergen.

Key sub-suppliers included

• Framo Flatøy, pump fabrication
• RadøyGruppen, subsea template fabrication, and 
• Luster Mekaniske Industri, pipeline supply.

In addition to the subsea boosting station, smaller modifications have been made to Snorre A, which receives the oil from Vigdis, and Snorre B, which supplies the new boosting station with power from a new umbilical supplied by Nexans. Wood has been the main supplier for the modifications and the marine operations have been carried out by Deep Ocean.

Load-out of pump station at OneSubsea, Horsøy near Bergen. (Photo: Jan Arne Wold & Audun Skadberg / Equinor ASA)

• VIGDIS FACTS
• The Vigdis field is in the Tampen area in the North Sea, in block 34/7 (PL 089)
• Equinor is the operator with an ownership interest of 41.5 per cent. The other partners are Petoro AS (30 per cent), Vår Energi AS (16.1 per cent), Idemitsu Petroleum Norge AS (9.6 per cent) and Wintershall Dea Norge AS (2.8 per cent)
• When the Vigdis field came on stream in 1997, the recoverable resources were estimated at 200 million barrels. So far, the field has produced 413 million barrels and estimated recoverable resources have increased to 475 million barrels. In comparison, the recoverable resources from Johan Castberg are between 450 and 650 million barrels of oil equivalent.
• The distance from the Snorre A platform to the closest subsea template on Vigdis is 5.8 kilometres.