McDermott: What Happens to Old Oil Rigs in a Greener Future?

The Harriet Alpha platform, positioned offshore Western Australia, is entering the final chapter of its operational saga under the guidance of Santos.

The Australian oil and gas producer has drafted in McDermott, an antipodean engineering firm, to decommission the rig. McDermott will handle all aspects of this process, from final removal and disposal of the platform and its various components.

This project is indicative of a shift towards greener practices, not only in terms of the energy transition, but in terms of waste conscientiousness too.

In this process, the remit of McDermott is going to cover more than just pulling apart old structures. Each step of the project will be made with an eye on environmental impacts, from transport to the repurposing of old materials.

A short history of Harriet Alpha

Since ceasing operations back in 2013, the Harriet Alpha platform has been an elephant in the room for Australian politicians.

The problem was simple but huge - nobody quite knew how to take it apart. 

It's not exactly like deconstructing a piece of IKEA furniture when you move house; the platform's massive structural complexity and the lack of local facilities capable of handling such a large-scale decommission safely became a real issue for Santos.

Propitiously, demolition contractor Liberty Industrial ran a study looking into solutions. This study was crucial in offering a project roadmap, providing multiple methodologies and cost assessments. With the study complete, the direction was clear: all roads pointed to McDermott.

Engineering and procurement solutions

McDermott’s involvement in the Harriet Alpha decommissioning is broad. Alongside managing the pivotal engineering tasks, the company is also handling procurement and fabricating specialised equipment needed for the safe removal of the platform. This includes the main platform structure, flare tower, an exploratory well and a subsea system that features two template wells.

These elements will be consigned back to shore where they will be methodically dismantled. 

Each step of the decommissioning process adheres to stringent safety and environmental standards, aimed at minimising ecological disruption in the marine surroundings.

The extensive nature of this task is highlighted by the fact that McDermott’s team in Perth will spearhead the efforts, backed by international specialists from as far afield as Indonesia and Malaysia.

Are oil platforms always taken apart when they are decommissioned?

When undertaking a project as large as removing an enormous oil platform from the ocean, the companies in charge will always require the counsel of ecologists.

You'd be forgiven for thinking that all ecologists would be in favour of removing these platforms from the natural world once they're obsolete, but that's not always the case. Speaking with the Guardian in 2023, scientist Milton Love of the University of California detailed his investigations into a disused oil rig off the coast of Santa Barbara.

Whilst examining the site, he and his team found that the underwater foundations of the rig were teeming with marine life. “It kind of crept up on me at some point that removing these things is immoral," he said.

Ann Scarborough Bull, another scientist on the team at the University of California, similarly said: “If you take away habitat, then there’s no going back. You would never allow the wilful destruction of a kelp bed, or of a rocky reef, even though rigs have similar biodiversity.”

With that being said, each case is vastly different and there is a point to be made for each approach.

A commitment to circularity

Embracing circularity—reusing and recycling materials—is at the heart of this project. McDermott has experience with this kind of procedure in Australia, and it showcases the company's commitment to infusing circular economy principles into the process of infrastructure removal.

With this approach, decommissioning transcends mere structural dismantling. Instead, it’s a transformative process where resources are meticulously recovered and repurposed, thereby diminishing the ecological footprint of such vast energy assignments. This is certainly a good argument in favour total removal.

By merging local knowledge with global expertise, McDermott is not just demonstrating that large-scale decommissioning tasks are manageable; they are also setting the stage for other companies in the energy sector to consider how their decommissioning activities affect broader sustainability goals.

Mahesh Swaminathan, McDermott’s Senior Vice President for Subsea and Floating Facilities, has been very involved in this process. “This is our largest decommissioning project to date," he says.

"It reflects our continued commitment to delivering bespoke solutions for the timely, safe and environmentally responsible removal of infrastructure at the end of its operational life cycle."

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