EnQuest has been hit with a warning from the UK safety regulator after a gas leak on the EnQuest Producer floating production, storage and offloading vessel that was caused by poorly-installed pipework.

An Improvement Notice served by the Health & Safety Executive (HSE) revealed a “significant” release – the second most serious type – occurred on 1 December from a pressure vacuum breaker valve.

Inspectors found that when this new valve had been installed, the upstream pipework had been configured in such a way that it allowed liquid into the valve to such an extent that workers were required to change the sealing fluid manually and on a regular basis.

The notice said that the “diluting effect of the liquid meant that the sealing fluid became unsuitable for its purpose because it altered the pressure vacuum settings for the valve”.

The HSE notice said that on 1 December, when workers were manually changing the sealing fluid, they emptied so much from the valve that the seal was lost, causing the gas release.

“You thereby failed to construct suitable upstream pipework for the pressure vacuum breaker valve and provide a suitable gauge so that your workers could accurately ascertain the liquid level in the pressure vacuum breaker,” the notice said.

A work order showed that 40 litres of fluid had also been removed from the breaker before 25 November.

EnQuest has been given until 12 July to comply.

An EnQuest spokesperson said: “EnQuest can confirm there was a gas release on its EnQuest Producer FPSO on 1 December 2016 during routine maintenance work on a relief valve associated with the crude oil storage system. Production was immediately shut down.

“On 3 December, whilst work was under way to restart production, the vessel’s gas detection system was activated during venting due to a change in weather conditions.

“In both instances, the platform’s safety systems worked correctly.

“We are working closely with the HSE to learn from the incidents and to implement the changes required to prevent re-occurrence and are on target to comply with the terms of the notices by the required deadlines.”

The EnQuest Producer FPSO began producing from the Alma-Galia fields in October 2015, behind schedule after delays to conversion work at Blohm & Voss shipyard in Hamburg and later OGN Group in Newcastle.

The Alma-Galia fields lie in blocks 30/24c and 30/25c, respectively, about 310 kilometres south-east of Aberdeen.

The project is a redevelopment of the UK North Sea’s first producing field, Argyll, and holds proven and probable reserves of 34 million barrels of oil equivalent.

Source: Upstream Online