Shell fined after major hydrocarbon release on rig linked to corroded pipework

Shell has been fined £560,000 following a major hydrocarbon release on a North Sea oil rig after it failed to properly maintain pipework for seven years.

The Health and Safety Executive (HSE) said the oil and gas giant neglected pipework on the Brent Charlie platform, causing an explosion risk.

It said the pipework deteriorated to such an extent that contained hydrocarbon fluids escaped, forming a potentially catastrophic explosive and flammable mixture.

Ventilation fans designed to mitigate the effects of escaped hydrocarbon gas did not function properly due to lack of maintenance, leading to a large release of mixed phase crude oil and gas from the corroded pipework, HSE said.

The uncontrolled hydrocarbon release occurred on May 19, 2017 and was the largest reported to HSE that year, involving 200kg of gas and 1,550kg of crude oil.

HSE said 176 staff working on the rig were put at risk from an explosion if the escaping hydrocarbon gas had ignited, but the probability of ignition was assessed to be less than 1%. 

Shell UK pleaded guilty to two charges under the Offshore Installations (Prevention of Fire and Explosion, and Emergency Response) Regulations 1995 and was sentenced on Aberdeen Sheriff Court on Tuesday.

The court heard the release occurred within the return oil line (ROL) pipework inside concrete leg column four.

An HSE investigation found deficiencies in Shell’s safety management system led to the release as the ROL pipework in column four was not properly maintained for several years.

It found the pipework was installed for short-term use and was due to be removed in 2010 but it remained in place for seven years.

After considering mitigating factors, the company was fined £560,000 by Sheriff Ian Duguid.

HSE offshore health and safety inspector Dozie Azubike said: “At more than 1,750kg, Shell Brent Charlie’s hydrocarbon release was the largest reported to HSE in 2017.

“This release occurred in a confined space with limited access – it is simply fortunate that no-one was in the leg at the time, or they could have been asphyxiated from the hydrocarbon-rich atmosphere, quite apart from any fire and explosion risk.

“Although the offshore industry has managed to reduce its overall number of hydrocarbon releases, in most years there are still several which, if ignited, would result in potentially catastrophic consequences.

“This case highlights the importance of oil and gas duty-holders reviewing their current management of change processes for temporary spools and their subsequent removal, strengthening inspection regimes to identify potential internal corrosion within pipework, and ensuring that inspection frequency of safety-critical equipment considers full analysis of the equipment’s maintenance history.”

A Shell spokesperson said: “Shell’s focus on safety and care for our people is deeply ingrained in our culture and drives every decision we make.

“When an alarm alerted us to a gas leak on Brent Charlie in 2017, the emergency procedure was followed immediately and no-one was harmed.

“The prosecutor has accepted our analysis that the risk of the leak igniting was extremely low.

“However, our usual preventative measures did not pick up this problem.

“We have investigated and made sure this cannot happen again.”