NOPSEMA, Australia’s offshore energy regulator, has issued a new direction to Woodside following the reports of two “dangerous occurrences” at the North Rankin Alpha platform.
The North Rankin Complex (NRC) is located in Commonwealth waters approximately 135 kilometres offshore from Dampier on the north-west coast of Western Australia.
The NRC is a single integrated facility comprised of two interconnected production platforms, the North Rankin Alpha (NRA) and North Rankin B (NRB) platforms, and associated subsea infrastructure including two export trunklines that run between the NRC facility and the onshore Karratha Gas Plant.
NOPSEMA is currently investigating structural integrity failure of one or more of the 24-tonne caissons that hang under the NRA offshore platform that could fall onto subsea gas and condensate pipelines below.
NOPSEMA’s direction states that while the likelihood of pipeline rupture is low, should it occur, loss of hydrocarbon (gas and condensate) from these pipelines may result in a major accident event.
Woodside is in the process of conducting non-destructive testing and subsequent engineering assessment of the structural integrity of each caisson. This testing and assessment are not yet complete and as a result the structural integrity is yet to be determined for all caissons.
The company has so far removed two of the original 16 caissons on the facility, the first in October and November of 2020 and the second in May of 2021. Of the remaining caissons, four are in service and the rest (10 caissons) are redundant (not in use) since 2013 (when the North Rankin B platform was commissioned) or 2014 (when the drilling derrick on NRA was deconstructed).
Woodside has advised NOPSEMA that regular communication with members of the workforce and health and safety representatives regarding the hazards and controls, including updates on planned remedial actions has been undertaken.
The directions are:
- 1: Take all reasonably practicable steps to ensure that the caissons at the NRA platform are safe and without risk to health, and ensure effective communication with members of the workforce and health and safety representatives is maintained to identify the hazards and manage the risks in undertaking these steps.
- 2: Complete the structural analysis and engineering assessment of the NRA caissons in service and redundant to determine the current status of their structural integrity.
- 3: Use the results of the structural analysis and engineering assessment to identify appropriate remedial actions and implement those actions as soon as reasonably practicable.
- 4: Submit to NOPSEMA a plan to implement the remedial actions identified in Direction 3 as soon as practicable; and submit to NOPSEMA, on a monthly basis, a report demonstrating progress with implementing the above directions and associated activities until all remedial actions have been completed.
Woodside is required to provide with documented evidence of its compliance with the notice of direction within one month of completion of each direction.
The direction was published a week after Woodside chief executive Meg O’Neill targeted a 30 per cent cut in operating costs over three years, with a focus on cuts on maintenance.