HSE highlights ‘inadequate’ offshore isolation practices

OFFSHORE oil and gas operators must improve their process isolation practices or risk serious accidents and fatalities, the UK’s Health and Safety Executive (HSE) has warned.

Following recent investigations, the regulator said it has identified recurring failings across offshore operations, including poor hazard identification and non-compliance with regulatory requirements.

Process isolation involves safely containing hazardous substances and gases during maintenance and operations. Failures can result in uncontrolled releases with potentially severe consequences.

The HSE has long published guidance on safe isolation practices through its HSG 253 standard, which applies specifically to offshore oil and gas installations. However, the regulator says many operators are either failing to follow the guidance or applying isolation methods that fall below acceptable standards.

Scott Templeton, principal specialist inspector in HSE’s Energy Division, said: “The problem is not the procedures on paper, it is that people are not following them.”

Poor practice identified

The HSE said common issues include operators using isolation processes that do not meet HSG 253 requirements or relying on lower-grade standards without proper justification.

Investigations have also found mismatches between the actual condition of plant equipment and its recorded design, leading to flawed isolation design and implementation.

Poor risk assessments were also identified as a major issue, with operators missing trapped fluids, pressure sources and non-return valves.

In a recent study of the UK offshore industry, the HSE recorded 180 dangerous occurrences and 92 hydrocarbon releases in 2024. Though there were no fatalities recorded, the HSE stressed that of the 477 inspection scores assigned to operators, 30% did not comply to standards and were marked as “poor, very poor or unacceptable”.

Call for improvement

The HSE said the identified failures are preventable and urged operators to strengthen adherence to existing standards. It is currently engaging with industry to help improve their practices.

It has also published a set of challenge questions for operators, including whether isolation procedures fully align with HSG 253 and how valve integrity is assured in complex systems such as flare headers.

“These failures are entirely preventable,” the HSE said. “The question is whether your organisation will prevent them.”

Updated guidance on offshore isolation practices is expected to be issued “soon”, according to the regulator.