Buzzard field operator Nexen is warning of lower production for the year after outages including the UK North Sea Buzzard field.

During the first quarter this year Buzzard output averaged 71,000 boe/d but during the second quarter the figure slipped to 49,000 boe/d.

Repairs to the cooling system at the Buzzard complex and the need to shut down the facility for final commissioning of a fourth platform have hit Nexen’s output in the second quarter.

“The facility will also be taken down in early August for the planned one-week shutdown of the third-party operated Forties pipeline,” Nexen says. “Once the fourth platform is available, production is expected to be strong as we will be able to almost double the number of available wells as we bring our higher concentration sour producers onstream.”

Buzzard remains Nexen’s largest producing asset and total production in the second quarter averaged 114,000 boe – 49,000 boe/d net to Nexen. “This reflects unscheduled maintenance to repair the cooling system and interruptions to a third-party operated natural gas export pipeline which constrain oil production to minimize gas flaring. While the repair work proceeded on schedule, production was lower than expected due to the gas export restrictions. Production is expected to be back to full rates in August,” Nexen said.

But the downtime has been used to bring forward a field maintenance programme which was originally scheduled for September. But Buzzard will be back offline again for a week in August while BP’s Forties pipeline which exports Buzzard crude undergoes a one-week shutdown.

Nexen’s production guidance for the year from Buzzard is now estimated at between 67,000 and 72,000 boe/d.

Nexen’s other UK production – mainly the Ettrick, Scott and Telford fields – averaged 32,000 boe/d in the first quarter and 35,000 boe/d in the second quarter, and the forecast average for the year is now at 28,000 to 32,000 boe/d.

“While we are disappointed with the downtime at Buzzard, we are making steady progress in all areas of our business. We continue to focus on developing our attractive opportunity portfolio and are advancing our near-term and longer-term value contributors to our business,” said Nexen presdient and chief executive Marvin Romanow, in the company’s second quarter statement.