Echo Yodel and Capella Plugging and Echo Yodel Decommissioning
|Submitted by||Woodside Energy Ltd|
|Submission date||17 April, 2020|
|Status||Under assessment (with NOPSEMA)|
|Link to previously accepted EP|
Phone: 08 9348 4000
Woodside Energy Ltd proposes to perform the following activities within Permit Areas WA-1-L, WA-23-L and in relation to the pipeline licenced under WA-9-PL:
• Permanently plug for abandonment the Yodel-3 and Yodel-4 production wells, and the Capella 1 exploration well. Permanent plugging will involve removing temporary plugs and installing permanent abandonment barriers in the wells using a Mobile Offshore Drilling Unit (MODU).
• Leave the Echo Yodel subsea infrastructure in-situ permanently to enable the infrastructure to continue to provide hard substrate to maintain the marine growth and habitat that currently supports local ecological functions.
The proposed Petroleum Activities Program is scheduled to occur between the first quarter of 2021 and fourth quarter of 2023. Permanent plugging activities for the three wells is expected to take about 20 to 60 days per well to complete. If performed as a single campaign, the cumulative duration could be up to 180 days (including mobilisation and demobilisation).
Two Operational Areas have been defined for the purposes of the EP assessment:
• Operational Area A (permanent plugging for abandonment activities): A radius of 4000 m around each well (Yodel-3, Yodel-4 and Capella-1). This Operational Area has been defined as the area in which permanent plugging for abandonment activities will occur and be managed under this EP.
• Operational Area B (leaving infrastructure in-situ permanently): A radius of 500 m (1000 m diameter) around the Echo Yodel subsea infrastructure that is to be left in-situ permanently, as well as the water column 20 m above this infrastructure. The Echo Yodel subsea infrastructure includes the Yodel-3 and Yodel-4 X-mas trees, pipeline, umbilical, infield umbilical termination basket (IUTB), umbilical termination assemblies (UTAs) and pig launcher. This Operational Area has been defined as the area in which the impacts and risks from leaving infrastructure in-situ permanently are addressed by this EP. Upon acceptance of the EP, this Operational Area will cease to exist.
The Operational Areas are located in Commonwealth waters within the NWS Province, as defined under the Integrated Marine and Coastal Regionalisation of Australia (IMCRA v4.0), in water depths of about 125 m to 136 m. The Petroleum Activities Program does not overlap with any established or proposed marine protected areas. The closest nearshore sensitive habitats to the Petroleum Activities Program is the Commonwealth boundary of the Montebello Australian Marine Park approximately 24 km to the south. Other sensitive habitats in proximity to the Petroleum Activities Program include Rankin Bank (12 km away from the defined Operational Area) and the Ancient Coastline at 125 m depth contour Key Ecological Feature which overlaps the Operational Area.