Offshore oil company Apache has been sentenced after they failed to provide written safety procedures for the depressurisation of an oil well, which led to the release of more than 1000kg of hydrocarbon gas at their Beryl Alpha production installation in the North Sea.
Aberdeen Sheriff Court heard how, on 2 June 2014, Apache had allocated a production technician to carry out a depressurisation task on one of their oil wells, which he had performed on previous occasions. However, they failed to provide him with any written safety procedures, expecting him to carry out this complex task from memory.
The Beryl Alpha rig has 40 well slots and some of its oil wells are gas-lifted to increase production efficiency. The use of gas lift means that there are large inventories of pressurised hydrocarbon gas, any uncontrolled release of these inventories is a potential major hazard event.
At approximately 19.40, four flammable gas detectors had detected gas in the area 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 HSE found that deficiencies in Apache’s safety management system (SMS) lead to a release of more than 1000kg of hydrocarbon gas. They had failed to carry out a risk assessment for depressurising gas lift wells, which meant there was a lack of suitable written procedures. The use of a formalised written procedure by Apache 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. 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 of Caledonia House, Prime Four Business Park, Kingswells Causeway, Aberdeen pleaded guilty to breaching regulation nine of the Offshore Installations Prevention of Fire and Explosion, and Emergency Response Regulations 1995 (PFEER). They were fined £400,000.
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 1000kg, 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.”
Source HSE Website 18/06/2021