Cooper Energy (CH) Pty Ltd proposes to undertake subsea installation of flowlines and umbilical control systems, and the tie-in of 4 wells from the Annie-2, Juliet, Nestor and Isabella gas fields to the existing Casino Henry Netherby (CHN) field infrastructure within Commonwealth waters of the Otway Basin. Cooper Energy (CH) Pty Ltd is a subsidiary company of the parent company Cooper Energy which was rebranded as Amplitude Energy in November 2024. The well connection and installation activities will be undertaken in Cooper Energy’s existing permits VIC/P44, VIC/L24, VIC/L30, VIC/P76 offshore from Peterborough in water depths of 56m to 74m.
The proposed scope of the installation and well connection activities covered by this Environment Plan (EP) consists of the following activities:
• Survey, inspection, maintenance and repair activities.
• Umbilical system laying (includes SUDU/UTAs and flying leads).
• Flowline system laying.
• Installation of subsea structures.
• Post-lay works (as-builts and stabilisation if required).
• Testing & preservation.
Planned activities will occur within an operational area defined by a 3 km corridor centred over each of the connecting flowlines from the well to connection with the CHN pipeline. The operational area is a 500 m radius (0.8 km²) long-term petroleum safety zone around the suspended development wells.
The operational area is north of primary shipping routes with some Commonwealth and State fishery overlap, and adjacent to the Southern Ocean offshore wind zone. During installation activities, the installation vessel and other support vessels may be visible from the coastline, similar to other shipping traffic. All equipment installed during the campaign will be on the seabed and will not be visible above the sea surface.
Activities will be conducted on a 24 hour, 7 days per week basis with the activity proposed to commence as early as 1 October 2027. The installation campaign is expected to take up to 150 days, in the event all wells are connected in a single campaign excluding environmental and operational delays. Pipeline integrity monitoring will be undertaken annually following completion of installation activities until commissioning of the wells.
The development wells and connecting flowlines to existing CHN facilities will remain suspended until commissioning which is currently proposed in Q2 2028. The future production from the well will be subject to future regulatory approvals and licencing and is not within the scope of this EP. This EP identifies and evaluates credible environmental impacts and risks associated with the activity and ongoing management of the pre commissioned flowlines.
