Case Study

Guiding New Zealand's first major decommissioning project

Two offshore oil platforms in the ocean.

We completed a technical review of the decommissioning application of the Umuroa and associated subsea oil fields for the New Zealand Environmental Protection Agency (EPA).

Just 50 km off the coast of New Zealand, the Umuroa offshore oil field has been operational for 13 years. Now it’s time to decommission it. The New Zealand EPA is trying to make sure the project is up to global standards.

This is a multimillion-dollar offshore decommissioning and restoration project, and it’s also a first for New Zealand.

John Cox, Global Decommissioning Director, Advisian

“Decommissioning projects of this magnitude need intensive planning and care, which is why the New Zealand Environmental Protection Agency approached us for an independent review to verify whether the approach aligned to international standards and best practice.”

Assessing technical accuracy and environmental impact

We formed a multi-office team to complete a technical review of the decommissioning plan for the floating production storage and offloading (FPSO) facilities. This included decommissioning subject matter experts from Vysus Group, our partner under Worley’s Global Decommissioning Collaboration.

Together, we assessed the approach to cleaning, de-mooring, and removing the FPSO structures. We looked at safely removing, recovering and disposing of the infrastructure and mooring systems, and the down hole plug and abandonment approach for the production and gas lift. 

Setting the project up for the next phase

We concluded that the New Zealand EPA decommissioning approach aligns with international regulations and best practices. Most importantly, it’s environmentally safe.

We also suggested pathways to realize environmental benefits. This included reducing impacts on the local seabed and water column and using the latest approaches to restore marine habitats with reefing.

The New Zealand EPA appreciated the expert advice Intecsea provided to the Board of Inquiry and the international experience they could draw upon in regards to decommissioning best practice.

Tim Roser, Senior Advisor, Environmental Protection Agency