Repurposing Offshore Platforms for Clean Energy Growth

Repurposing Offshore Oil and Gas Platforms for a Sustainable Future

As the global energy landscape evolves, many offshore oil and gas platforms are reaching the end of their operational lifespan. These structures, once central to energy production, are now being reimagined as valuable assets for sustainable development. From carbon capture to marine research, nations are exploring innovative ways to give these aging infrastructures a second life.

Carbon Capture and Storage (CCS)

One of the most promising repurposing strategies is carbon capture and storage (CCS). Many offshore platforms already have the infrastructure in place to store CO₂ underground, with pipelines originally used for oil and gas transportation now being adapted to move carbon from onshore operations to the ocean floor.

The UK’s HyNet North West project, led by Eni, is a prime example of this concept in action. This initiative will use 149km of repurposed pipelines to transport CO₂ from industrial sites to depleted gas reservoirs beneath Liverpool Bay. This project serves as a real-world test case for large-scale CCS integration.

Alastair Bisset, Head of Decommissioning at the North Sea Transition Authority, highlights that the UK has significant potential for CCS and hydrogen storage. His team identified over 100 pipelines that could be suitable for such projects, potentially saving hundreds of millions of pounds by avoiding the need for new pipeline construction.

Jon Gluyas, an expert in CCS at Durham University, emphasizes that the proximity of certain gas fields to shore, combined with favorable sea conditions and known geology, makes them ideal candidates for CCS. While technical challenges remain, such as adapting topside facilities and ensuring CO₂ is dry to prevent corrosion, much of the expertise from the oil and gas industry can be directly applied to CCS operations.

However, Gluyas stresses that government leadership is essential. Just as the government played a pivotal role in developing the oil and gas industry in the 1960s, it must now take the lead in establishing the necessary infrastructure for CCS projects.

Hydrogen Hubs

Another emerging opportunity is the use of offshore platforms for green hydrogen production. As nations seek to transition to clean energy, hydrogen hubs are gaining attention. These hubs would involve converting existing platforms into facilities for producing, storing, and transporting hydrogen.

Julio Garcia Navarro, a programme manager at TNO, explains that many offshore platforms could be retrofitted with electrolyser topsides to produce hydrogen. These systems could then connect to existing gas connections and transport the hydrogen to land using the same pipelines.

This approach is particularly feasible when paired with offshore wind farms, which can provide the renewable energy needed to power hydrogen production. Projects like the PosHYdon pilot in the Dutch North Sea demonstrate the viability of this concept.

Navarro notes that while the technology is sound, the main challenge lies in streamlining planning and policy around these repurposing efforts. A unified strategy is needed to coordinate between stakeholders, as the issue is more political than technological.

Offshore Wind

While no large-scale wind farms have yet been built directly on former oil platforms, several pilot projects and feasibility studies suggest the idea is both technically and economically viable. In the Netherlands and the UK, initiatives by Nexstep and TNO have explored converting redundant jacket foundations into substructures for wind turbines or offshore substations.

These studies found that repurposing existing infrastructure can lead to cost and environmental savings by avoiding a full infrastructure overhaul. Integrating green hydrogen production into offshore energy infrastructure offers a powerful way to both decarbonize and accelerate offshore wind projects, helping meet governmental wind ambitions.

The Dutch government, for instance, has set a target of 70GW of offshore wind by 2050, although recent changes to its 2040 target have introduced some uncertainty. Nevertheless, the potential for using decommissioned infrastructure in the next 10–15 years remains strong.

Aquaculture

Some offshore oil and gas platforms are also finding new purpose below the surface, serving as commercial fish farms. Tyler Sclodnick, a principal scientist at Innovasea, notes that oil rigs can act as platforms for aquaculture operations, offering superior communications, power reliability, and living conditions compared to bespoke setups.

However, decommissioning work is still required, and facilities must be modified to operate within the tighter margins of commercial aquaculture. While repurposing oil platforms for aquaculture may not always be the most cost-effective option, especially when platforms are located far from shore, the model could become increasingly viable as the aquaculture industry expands into remote ocean environments.

Marine Research Stations and Artificial Reefs

Decommissioned infrastructure naturally acts as a “fish aggregator,” creating habitats that support biodiversity. In the US, "Rigs-to-Reefs" programs encourage oil companies to convert retired oil rigs into artificial reefs, removing upper structures to make them safe for boats and divers.

These structures also serve as ideal locations for marine observatories, offering built-in power, stability, and offshore access for researchers. They can be used to monitor environmental conditions such as ocean acidification and temperatures, enabling long-term data collection with minimal new construction.

Proposed projects, such as the Acoustic Neutrino Detection In a Multidisciplinary Observatory concept in the Adriatic Sea, aim to repurpose offshore oil rigs to house sensors tracking acoustic ocean signals.

Dive Sites

With decommissioned rigs often acting as hubs for marine life, the option to turn them into dive spots is also being explored. Ensuring safety is critical, as divers typically limit themselves to about 30m depth. Infrastructure needs to be shallow enough for access and sunlight to reach, so the top parts of the rig are often removed to prevent hazards.

Malaysia’s Seaventures, the world’s first oil rig-turned-dive resort, has operated off Mabul Island since 1997, with the site now housing a floating hotel for guests. Other examples include Platform HI-A-376 in the Gulf of Mexico and the Eureka, Ellen, and Elly rigs in California.

Rocket Launch Pads

Another surprising concept is the conversion of offshore rigs into rocket launch platforms. With these sites designed to bear immense loads, they offer a means of de-congesting the increasingly competitive orbital launch space.

Various nations have shown interest in this idea. Last year, Italy’s space program announced it would reopen its ocean launch pad off the coast of Kenya, while German start-up Offshore Spaceport Alliance proposed an offshore space port in the North Sea. SpaceX also explored the possibility of purchasing two oil rigs in the Gulf of Mexico for this purpose.

While a real-world example is yet to be seen, interest in the sector is growing. As satellite demand increases and companies pursue high cadence launch strategies, offshore platforms could evolve from novel experiments to core infrastructure in the space economy.