Woodside Energy (Australia) Pty Ltd (formerly BHP Petroleum Australia Pty Ltd) is planning for the safe and sustainable closure of the Stybarrow Development in petroleum licence WA-32-L off the coast of Western Australia, around 56 km north-west of Exmouth, and in water depths of about 810 m – 850m.
The removal of the majority of the Stybarrow facilities (well heads, flexible flowlines, DTM, moorings, subsea ancillary equipment) within the WA-32-L is subject to an environmental approval currently under assessment.
The remaining equipment, covered under this EP, is 9 anchors, 10 suction base foundations piles and a historical exploration wellhead that was unable to be removed at the time of plug and abandonment. The scope of the EP includes the decommissioning of the equipment in situ in perpetuity. An assessment found that the leave in situ decommissioning option was preferred as it meets legislative requirements, is technically feasible, provides equal environmental outcomes, and has fewer health and safety risks when compared to removal. Impacts associated with the perpetual presence of the equipment include long-term degradation of the materials and potential displacement or interactions with future trawl fishers. These impacts and risks have been demonstrated as ALARP and acceptable in the EP.
The Petroleum Activities Program will end on acceptance of this EP by NOPSEMA and the expected duration of the activity will be zero days.