Australia’s offshore safety regulator has hit Jadestone Energy with several direction notices following a spill during the offtake of oil from the Stag oilfield off Western Australia.
According to a statement from Nopsema, the Maersk Tacoma offtake vessel had been moored at the Stag facility catenary anchor-leg mooring (CALM) buoy for about one week when the master of the offtake tanker observed traces of oil around the vessel on 26 September.
It was later found that marine breakaway coupling (MBC) in the import floating hose assembly connected to the tanker had activated.
This was reported to the Stag platform offshore installation manager, with the crude transfer then halted.
Nopsema also noted that this was the first time a vessel had been loaded under new offtake procedures at Stag using transient slow-load tankers, which are on location for periods of up to three months.
A subsequent investigation on 2 October found the MBC was not positioned in accordance with the approved safety case nor the original equipment manufacturer's recommendations.
It was also found that the master of the offtake tanker did not maintain the minimum hawser tension needed to prevent the import floating hose assembly and MBC making contact with the hull or hawser under certain environmental conditions.
Nopsema said it is believed the tanker could have sprung close to the CALM buoy in bad weather causing the MBC to contact the hull of the tanker and activate. Another theory points to the tanker not maintaining sufficient standoff distance, which could have inadvertently caused the hawser to rest on the floating hose, inducing additional stress on the MBC and causing it to activate.
Oil spill response
During the investigation it was also found Jadestone did not adequately implement its oil spill response arrangements, while Nopsema also found the operator underestimated the full extent and duration of the oil spill.
According to the regulator, Jadestone communicated the worst case volume that could have been released was 630 litres, however Nopsema calculated that 161 to 1288 litres of oil had been released, based on aerial and surveillance information.
As a result of the incident, Nopsema issued Jadestone with six directions, including a direction to identify and implement interim control measures to prevent any recurrence of an inadvertent parting of the MBC during offtake operations as soon as practicable.
It also directed the operator to commission and implement an engineering and operational review of the import hose configuration, as well ensuring that the integrity of the equipment is maintained at all times.
It also called for Jadestone to review and update systems to ensure an adequate level of oil spill response training and competency is in place and maintained by all personnel, as well as carry out testing of the oil spill response arrangements using a worst case oil spill scenario.
Jadestone will also be required to review, identify improvements, update systems, practices and procedures and implement them to ensure offtake tanker vessel masters are aware of hazards.
Nopsema has also directed Jadestone to prepare and provide a report on how the directions have been implemented, within 14 days of the completion of each direction.
Beach pulled up on crane corrosion issues
The directions issued to Jadestone follow a recent improvement notice issued to Beach Energy on 24 November in relation to its operations in the Bass Strait, off south-east Australia.
The improvement notice revealed that an inspection carried out by Nopsema on 15 September on the Yolla-A facility found Beach had failed to take "all reasonably practicable steps" to ensure the facility’s crane was safe and without risk.
An inspection of the crane in December 2018 identified structural corrosion issues to be investigated and remediated, with the crane then removed from service following subsequent inspections in March 2019.
However, the crane was returned to service in the same month, at a de-rated capacity of six tonnes, following a de-rating assessment by the crane’s manufacturer.
The rated capacity was increased to 7.5 tonnes in July following some repairs and a further re-rating assessment being carried out on 28 June.
However, Nopsema found in its investigation that Beach did not assess the risk of operating the crane in accordance with the management of change procedures required by the facility safety case following either of the re-rating assessments.
It also found that a load test carried out on the crane on 28 June was not completed in accordance with any recognised standard, while it was also discovered that no qualified or accredited inspector was present during the test.
Nopsema also found damage may have been incurred in the process of load-testing, which Beach would not be able to determine as no post-load test was carried out, meaning the crane may have been put into service with unknown defects created during the load test.
Nopsema also noted that no third party annual crane inspection was carried out in 2019, or since, while no operational risk assessments had been carried out in relation to the overdue inspection.
As a result of the inspection, Nopsema found that the crane was “operated in a condition that increased the potential for failure”, while an inspector found Beach failed to take all reasonably practicable steps to ensure that the crane was safe and without risk to the health of personnel.
The inspector also stated they believed Beach was likely to use the crane again in contravention of occupational health and safety laws.
As a result, Nopsema has given Beach 60 days, from 24 November, to prevent or reduce risk posed by the crane, including by carrying out the overdue annual crane inspection.
It also called on Beach to complete a management of change to assesses the risks of operating the crane in a de-rated capacity, as well as update the maintenance process to ensure crane load-testing is conducted to appropriate standards.