BHP Petroleum Pty Ltd (BHP) is planning for the safe and sustainable closure of the Stybarrow Development in petroleum licence WA-32-L, located in Commonwealth waters around 55 km north-west of Exmouth, in water depths of approximately 810 - 850 m.
Production from the Stybarrow Field commenced in 2007 and ceased in 2015. BHP is now planning for the progressive decommissioning of the Stybarrow Field, with the first approvals being sought for the removal of the subsea equipment and ongoing field management activities until the equipment is removed. The Well Plug and Abandonment (P&A) and equipment proposed to remain in situ will be subject to separate future environmental approvals.
The scope of the petroleum activities include:
The removal of the following subsea infrastructure:
o The DTM and associated mooring legs and mooring support buoys; ~60 km of flexible lines encompassing the flexible risers; flexible production flowlines; gas and water injection flowlines; 19 km of umbilicals; 10 wellheads and Xmas trees; hydraulic jumpers; a water injection manifold; 5 subsea distribution units; 2 umbilical termination assemblies; and 15 anode skids.
o The subsea infrastructure removal activities are expected to be conducted over a period of around six months, with activities required to be completed before 31 March 2025. Typically, only two (but up to six) project vessels will be within the operational area during removal activities.
Continuation of field management scopes on the subsea infrastructure until it is removed, or alternatives to full removal are accepted by NOPSEMA.
The petroleum activities do not overlap with any established or proposed marine protected areas, with the closest being the Gascoyne and Ningaloo Australian Marine Parks located 5 km and 24 km respectively, from the operational area.