Woodside has submitted a proposal to NOPSEMA to undertake plug and abandonment activities within offshore petroleum production licence VIC/L22 and field maintenance activities within VIC/L22 and adjacent pipeline licence VIC/PL33. The activities are within Commonwealth waters, approximately 11 kilometres south, south-west of Port Campbell, Victoria.
The offshore wells were drilled in late 2002, and the offshore and onshore pipeline was laid in 2003. The construction of the onshore gas plant was completed in December 2004, and the facilities were commissioned and commenced production in January 2005.
Production of the field ceased in September 2019 and the Minerva-3 and Minerva-4 wells were suspended. A vessel-based campaign was conducted in the first quarter of 2021 to disconnect flowlines from wells and install additional barrier plugs.
There are four wells required to be permanently plugged and abandoned using a moored semi-submersible mobile offshore drilling unit (MODU). There are two gas production wells, and two suspended exploration wells all currently in a state of preservation.
The program for the EP will include:
- Vessel based cleaning, inspection, and preparation of wells prior to MODU-based plug and abondonment scope;
- Permanent plug and abandonment of the four Minerva wells using a moored MODU;
- Disconnect of well infrastructure (Xmas trees and wellheads) above the mudline;
- The potential temporary wet storage of Minerva wellheads and XT’s within the operational area prior to field removal during decommissioning operations, if not removed via the MODU whilst on location; and
- The maintenance of all remaining subsea infrastructure including the Minerva subsea pipeline and umbilicals (VIC/PL33), which runs from the Minerva wells to the boundary of the Victorian State Waters.
The works are proposed to be undertaken between the third quarter of 2023 and end of June 2025. The anticipated duration of MODU-based infield operations is less than two months.
