Australia’s Woodside has submitted a decommissioning plan for subsea infrastructure no longer required for production activities from the Echo Yodel field offshore Australia and the plan is now being assessed by the country’s offshore regulator.
The plan was submitted on 17 April to Australia’s National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA).
According to the offshore regulator, Woodside’s plan proposes to 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).
Woodside will leave the Echo Yodel subsea infrastructure in-situ permanently to enable the infrastructure to continue to provide a 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.
As for the infrastructure that will be left in-situ, it includes the Yodel-3 and Yodel-4 Xmas trees, pipeline, umbilical, infield umbilical termination basket, umbilical termination assemblies, and the pig launcher.
It is worth noting that the activities do not overlap with any established or proposed marine protected areas with the closest nearshore sensitive habitats being the boundary of the Montebello Australian Marine Park some 24 kilometres to the south.