Repsol Sinopec Resources UK (RSRUK) has been reprimanded by the UK offshore safety regulator after overdue repairs and a failure to carry out maintenance on a power generation turbine led to a gas leak last month on the Piper Bravo platform.
The Health & Safety Executive (HSE) said RSRUK failed to ensure that a power generation turbine — called Turbine D — and its exhaust system was in working order and good repair.
HSE said the exhaust ducting had been inspected in January 2020 by a third-party contractor when it was recommended that repairs were carried out on the exhaust duct.
HSE found RSRUK did not implement these repairs and the failure led to an uncontrolled release of gas from the exhaust system ducting during the start-up of the turbine on 5 May.
This resulted in a full platform shutdown and all personnel were brought to muster as a precaution.
At that time of the incident, the turbine was 30,000 running hours past its last planned major overhaul, which had been due at 56,000 running hours.
HSE has served the operator with an Improvement Notice, with which it must comply by 30 September.
Piper Bravo was installed in 1993 to replace the stricken Piper Alpha facility, which was destroyed by fire and explosions in July 1988 with the loss of 187 lives following a gas leak.
An Operational Risk Assessment (ORA) identified a number of potential hazards caused by running past the recommended major overhaul date and a number of areas where mechanical damage on the inlet could result in debris being sucked into the turbine which could result in a catastrophic failure.
However, the risk of a hydrocarbon release caused by the identified failures of the exhaust ducting was not identified within this ORA.
In addition, at the time of the incident on Turbine D, Turbine C was out of service, the cause of which is unknown. Work on this turbine was also overdue.
An RSRUK spokesperson said: "We can confirm that we have received an Improvement Notice from the HSE in relation to the management of Piper Bravo power generation.
"We are proactively engaging with the regulator to manage the issues identified.
"Safe operations in all company activities is a priority and we are committed to ensuring the safety and wellbeing of all personnel who work on our sites."
An ORA is a decision taken at the discretion of a dutyholder or operator to bypass systems or equipment that are not working optimally to allow production or work to continue on an offshore installation.