LONDON, Feb 27 (Reuters) - Britain's largest oilfield, Buzzard, is pumping below capacity at around 80,000 barrels per day (bpd) following a problem with a separator at the Kinneil oil terminal on the Scottish coast, trade sources said on Wednesday.
Output is expected to remain at that level until Friday, when the North Sea field begins a four-day shutdown for planned pipeline inspection and maintenance work, the sources said.
In the industry this is known as "pigging" after the pipeline inspection gauge device used to perform the maintenance.
"We are taking advantage of the output restriction in the (Forties Pipeline System) to change a defective valve in our gas system," said a spokesman at Buzzard's operator Nexen.
"This will also coincide with our planned shutdown at the end of the week for maintenance of our pig launcher."
Buzzard, which normally pumps 200,000 bpd, is the largest contributor to the Forties crude blend, the most important of the North Sea crudes underpinning the Brent crude benchmark.
Lower-than-expected output from Buzzard in February has already pushed back the loading dates for eight February and March Forties cargoes, but further delays are possible.
On Wednesday, the loading dates for cargo F0302 were pushed back to March 6-8, traders said. This cargo was orginally due to load on March 3-5, and had already been deferred once.