Centrica Energy is to extend its contract for the Hummingbird Spirit until March 2016.
The cylindrical FPSO, owned by Teekay, has been operating on the Centrica-operated Chestnut field, north east of Aberdeen, in the central North Sea since 2008.
It has, so far, produced more than 13MM bbls and is currently producing about 7000 bbl/d.
The field was initially expected to produce about 7MM bbls over three years. However, work undertaken by Centrica Energy means that the Chestnut field is now expected to produce significantly more, with recoverable reserves currently estimated at about 18MM bbls.
This has included developing a water injection side-track well, sustaining high production efficiency,
The Hummingbird Spirit, which stores more than 200,000 barrels of oil, was the first vessel of its type to be installed in the North Sea. It has multiple, flexible risers to carry oil from the two production wells and water to the single injection well.