The NSTA has imposed a penalty of £125,000 (US$153,762) on CNOOC Petroleum Europe Ltd. for venting without consent at its Buzzard field, 60 miles northeast of Aberdeen, on two separate occasions in the span of two weeks.

The NSTA has now issued fines totaling £825,000 ($1 million) for flaring or venting consent breaches since late 2022.

It says flaring and venting make up about one-fifth of the UK oil and gas industry’s offshore production emissions. Starting Jan. 1 2025, the NSTA says £500,000 is the new starting point for considering fines relating to breaches of flaring and venting regulations.

So what happened at Buzzard?

In late May 2022, CNOOC detected a leak in the line that supplies fuel needed to keep the flame lit on Buzzard’s flare stack. CNOOC shut off the fuel line and began venting excess gas into the atmosphere unignited.

The company confirmed to the NSTA on June 1 that it had breached the annual consent for Buzzard, only to continue venting until a fault with a generator led to production operations shutting down on June 3.

Despite being aware it did not have a valid consent for additional venting, CNOOC restarted production and export activities from Buzzard on June 9, then further venting took place due to a faulty valve on the fuel gas system, the NSTA explained. CNOOC continued to produce, and therefore vent, through to June 13.

Between May 31 and June 13, CNOOC exceeded its annual venting limit for Buzzard by 435.13 tonnes of gas. A revised consent was granted on June 14, bringing Buzzard back in compliance for any further venting during the rest of 2022.

The NSTA says CNOOC cooperated throughout the investigation and introduced measures to prevent recurrences, including improved monitoring and a new approach to consent applications. Previously, CNOOC had only requested consent to vent minimal volumes of gas, as venting was uncommon on Buzzard.