Griffin Decommissioning and Field Management
Activity type | Decommissioning, dismantling or removing a facility |
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Activity subtypes | Any other petroleum-related activity |
Lifecycle Classification | Decommissioning |
Submitted by | Woodside Energy (Australia) Pty Ltd |
Submission date | 22 December, 2021 |
Subtype | Revision |
Decision date | 21 November, 2023 |
RMS ID | 6867 |
Status | Finalised |
Outcome | Accepted |
Link to previously accepted EP | 4404 - Griffin Decommissioning and Field Management |
Contact |
Woodside is planning for the safe and sustainable closure of the Griffin facilities, located in Production Licence WA-10-L off the coast of Western Australia, 65 km north-west of Onslow and 94 km north-east of Exmouth, in a water depth of approximately 130 m.
The Griffin Field comprises 12 former subsea oil production wells, which were permanently plugged in 2017, as well as associated subsea infrastructure, which has been flushed of hydrocarbons. A Gas Export Pipeline (GEP) extends from the field through Commonwealth (pipeline licence WA-3-PL) and State waters (pipeline licence TPL/10) to the former onshore Griffin Gas Export Facility, south of Onslow.
Decommissioning of the Griffin Field is planned to be undertaken in stages under relevant Commonwealth and State Government approvals, with the first stage including the removal of flowlines, wellheads and subsea ancillary equipment from WA-10-L. These activities will be managed under this Griffin Decommissioning and Field Management Environment Plan (EP). This revised EP will also cover the removal of the wellhead of an exploration well in neighbouring title, WA-12-L, along with ongoing field management activities on the subsea infrastructure and the GEP in Commonwealth waters, as required until permission is granted to relinquish title/s.
The scope of the EP includes the removal of thirteen wellheads and guide bases, twelve Xmas trees, the full removal of the riser turret mooring (RTM), six RTM mooring lines, nine flexible production risers, (~47km) of flexible production flowlines, (~12km) rigid production spools and flow lines, twelve electrohydraulic umbilicals and flying leads, Pipeline end manifold, six mooring chains, four distribution skids and assorted mud mat structures (heat exchanger, 3 x Umbilical termination assemblies and electrical distribution units, choke skid, 17 x pyramid anode skids).
Removal activities managed under this EP are planned to commence no sooner than Q3 2023, pending regulatory approvals, support vessel availability and weather constraints. The activities covered in the EP may occur at any time of year, with completion by the end of calendar year 2024.
The Gas Export Pipeline and remaining field equipment (piles, anchors, concrete gravity bases) will be subject to separate future environmental approvals.