Minerva Plug and Abandonment and Field Maintenance
|Activity subtypes||Any other petroleum-related activity|
|Submitted by||Woodside Energy (Victoria) Pty Ltd|
|Submission date||30 June, 2022|
|Status||Under assessment (with titleholder)|
|Link to previously accepted EP||4887 - Minerva Plug and Abandonment and Field Maintenance|
Woodside proposes to undertake plug and abandonment (P&A) activities (drilling activities) within offshore petroleum production licence VIC/L22 and field maintenance activities (other activities) within VIC/L22 and adjacent pipeline licence VIC/PL33. The activities are within Commonwealth waters, approximately 11 km south, south-west (SSW) of the township 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 Q1 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 this EP will include:
• Vessel based cleaning, inspection, and preparation of wells prior to MODU-based P&A 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.
Removal of any remaining infrastructure within the field is not described as part of this EP.
The EP provides for the P&A scope to be undertaken from Q3 2023 to end Q2 June 2025. Whilst this EP provides for the activity to be undertaken within this window of opportunity, the anticipated duration of MODU-based infield operations is less than 2 months.
The P&A activity will be undertaken 24 hours a day, 7 days a week.
This EP shall remain in-force until such time as the planned P&A activities have been completed and a separate approval has been obtained for field decommissioning and removal of development infrastructure remaining in VIC/PL33 and VIC/L22.