OSLO/LONDON, Aug 13 (Reuters) - Production is shut at twosmall fields in the Norwegian section of the North Sea, whoseoil is exported via BP's Ula field and the Ekofisk fieldcentre, BP said on Tuesday.
On Friday, Norwegian oil company Noreco saidproduction at the small Oselvar field was shut until the end ofSeptember due to a problem with a gas compressor at the Ulafield, to which Oselvar is tied.
On Tuesday, BP said production at two other fields tied toUla, Blane and Tambar, had been stopped for the same reason.
"Blane is not in production. Tambar is not in production,"said Olav Fjellsaa, a spokesman for BP Norway. All three fieldsfeed into the Ekofisk stream, one of the four North Sea crudesthat underpin the price of dated Brent.
A BP spokesman based in Aberdeen said the gas turbinecompressor had been due for a change-out, so this work wasbrought forward after it broke down last week. The new turbineis expected to be up and running by mid-September, he added.
Tambar is expected to produce an average of 2,000 barrelsper day (bpd) this year, while Blane will produce 1,000 bpd,according to estimates by the Norwegian Petroleum Directorate.