Apache has been fined £400,000 ($556,000) after a failure to provide a worker with written safety procedures for the depressurisation of an oil well led to the release of 1000 kilograms of gas at its Beryl Alpha platform in the UK North Sea.
Aberdeen Sheriff Court in Scotland heard how on 2 June 2014 a production technician had been allocated to carry out a depressurisation task on an oil well — A86 — that he had performed on previous occasions.
However, Apache failed to provide him with any written safety procedures, expecting him to carry out the complex task from memory.
The Beryl Alpha facility, in Block 9/13, has 40 well slots and some of its oil wells are gas-lifted to increase production efficiency.
The use of gas lift means there are large inventories of pressurised hydrocarbon gas, which could potentially be a major hazard if released without control.
According to the Crown Office, Scotland's public prosecutor, at about 7.40pm that day, a rush of gas was heard coming from Area 6B of the platform. Four detectors detected gas and automatically activated the platform water deluge system.
The general platform alarm sounded and all 134 workers went to their muster stations.
The gas release continued and the installation remained at muster station for more than six hours.
An investigation by the Health & Safety Executive (HSE) found that deficiencies in Apache’s safety management system lead to the release of 1035 kilograms of hydrocarbon gas — the largest gas release on the UK continental shelf in 2014.
It was found that Apache failed to carry out a risk assessment for depressurising gas lift wells, which meant there was a lack of suitable written procedures.
A formalised written procedure would have ensured that this task was carried out correctly in a safe and consistent manner across all staff shifts, preventing the safety-critical emergency shutdown system from being disabled during well depressurisation.
'Potentially catastrophic'
The prolonged duration and magnitude of the release was a direct consequence of the inadvertent defeating of the emergency shutdown system in this instance.
Apache Beryl Limited pleaded guilty to breaching regulation nine of the Offshore Installations Prevention of Fire and Explosion and Emergency Response Regulations 1995.
The £400,000 fine was reduced from £600,000 for the guilty plea.

Speaking after the hearing, HSE principal inspector Dave Walker said: “Although the offshore industry has managed to reduce its overall number of hydrocarbon releases, it is still the case that in most years there are several, which are of such a size that if ignited would result in potentially catastrophic consequences.
“At more than 1000 kilograms, Apache’s Beryl Alpha’s hydrocarbon release was the largest reported to HSE in 2014. It occurred during complex work on a well, which used a large volume of high-pressure gas to improve production rates, the hazardous nature of which had been highlighted in specific HSE guidance.
“The depressurisation of an oil well is a safety-critical task, and so should have been formalised in a written procedure to set out a specified sequence of operations to perform the task correctly and prevent potential fatal consequences.”
Alistair Duncan, head of the health & safety investigation unit at the Crown Office, said: “Apache Beryl Limited accepted liability and the Crown accepted their guilty plea to the contravention of the regulations.
“Hopefully this prosecution will serve as a reminder that failing to have sufficiently robust procedures can have potentially serious consequences.”