Reusing & Recycling Decommissioned Materials: Is the Glass Half Full or Half Empty?

By Melissa Marques, Umit Bititci, Amos Haniff & Matt Blair

© anttoniart/AdobeStock

The decommissioning and recovery of offshore platforms from the UK Continental Shelf (UKCS) is a societal issue.

In addition to costs being paid through tax reliefs and repayments agreed with the government, there is an environmental impact associated with removing obsolete assets and dealing with the material ‘waste’ produced.

Thus far, most materials recovered have been exported for recycling; however, recycling (particularly of offshore assets) is an energy-intensive process that contributes to climate change.

Although reusing, repurposing, and remanufacturing are preferable solutions, the amount reused is currently negligible. With previous studies highlighting the potential to reuse decommissioned equipment and materials, Heriot-Watt University in Edinburgh, collaborated with the decommissioning sector’s only member organization, Decom North Sea, to create a report which has analyzed the drivers and barriers to reuse from a systems perspective.

Ultimately, the partners sought to understand why the uptake of reuse did not take place to date and the potential interventions for change.

As we know, oil and gas extraction is a declining industry in the UK. Having originated in the 1960s, activity towards the end of the last decade has been reduced by two-thirds.

While past governments and taxpayers benefited from the £330 billion net tax paid by the industry since the 1970s, the decline in production and the need to decommission assets have turned the tables.

Current operator tax relief results in taxpayer ‘costs’ that have been estimated between £17 billion and £24 billion (OGUK, 2019; NAO, 2019).

In addition to its high costs, decommissioning is of interest to society from an environmental perspective. There are over four million tonnes of infrastructure in the UKCS (ARUP et al., 2014) and while most materials recovered to date have been sent to recycling, this process has a considerable environmental impact. For instance, steel - the most abundant material in platforms in the UK (ARUP, 2014) - is, in theory, infinitely recyclable; however, this is an energy-intensive process due to the need for re-smelting. Any reduction in CO2 emissions depends upon the cleanliness of the energy and technology utilized.

To help combat this, the circular economy is a widespread concept that defends the systemic reduction of resource input and waste by re-circulating materials. While recycling is vital to create materials loops, the circular economy is based on the principle that reusing, repurposing and remanufacturing are preferred approaches; using materials again with minimum processing and changes to their original form. For steel, this would eliminate the need for re-smelting. As UK steel is mostly recycled with an impact of over 1 tCO2/ t crude steel, reuse would create a potential to save over four million tonnes of CO2 by eliminating the need to smelt, in addition to a reduction of emissions from logistics and other processes.

However, despite the potential for reuse, evidence indicates that most offshore materials are still recycled or landfilled with little attempt to reuse, repurpose, or remanufacture.

Do we need to Decommission At All?

Ultimately, the need to decommission platforms was decided at the OSPAR Convention of 1998, under the principle that seabeds are not ‘dustbins’ for human activities. While environmental organizations were pleased with the decision at the time, there was also criticism of it being the result of an environmental lobby, rather than scientific evidence.

Today, the benefits of removing platforms compared with leaving the whole or parts in situ are not yet fully understood. Bold solutions could include repurposing whole platforms for carbon capture, renewable energy, or other uses. The analysis of such options is covered in the decommissioning plans that operators are required to submit to the regulator (OPRED), which include justification of why a derogation for reusing/repurposing the entire platform has not been pursued.

Reasons why operators prefer not to reuse whole platforms are vast. However, what is not fully assessed in most decommissioning plans is the possibility of reusing structures as artificial reefs. There are ongoing debates surrounding the ‘rigs-to-reefs’ idea, based upon the principle that removing offshore structures covered with ‘marine growth’ could cause more harm than good to the ecosystem.

Leaving platforms in place through repurposing would avoid all emissions and environmental impact caused by the removal of assets, construction of new facilities, as well as emissions from recycling - although with an eventual impact to the seabed and arguably opening precedents to other industries. However, while the debate is still alive, materials continue to be decommissioned in the North Sea and come to shore. For these, overseas recycling with higher emissions has been the rule and reuse has been negligible. Why?

Once an offshore platform in the UK reaches its ‘end of life’, operators are required to submit a decommissioning plan to OPRED at the UK Department for Business, Energy and Industrial Strategy (BEIS). BEIS promotes the circular economy, but only in general terms and without specific emphasis on reuse, repurposing, or remanufacturing. The implication is that it defers the decommissioning waste problem to the latter stages with a focus on recycling. Consequently, this is exactly the position adopted by operators in their plans.

The 95% Recycling Myth

And so, it is no surprise that it is commonly stated within the industry that up to 95-98% of materials from decommissioning are recycled (SEPA, n.d.). However, upon analysis of decommissioning plans and close-out reports, this appears to be misleading for three reasons.

Firstly, operators draw the boundaries of analysis narrowly around the removal operations and materials brought ashore only. This leaves out any materials left in situ. Secondly, decommissioning projects are of great scale, often involving the creation of bespoke equipment.

Only emissions from demolishing activities are calculated within close-out reports; however, they do not address the reusability of the equipment utilized during decommissioning.

The final argument around the 95% recycling rate myth refers to the amount reported as ‘recycled’, which is, in fact, the amount ‘sent to recycling’ (usually overseas). There exist losses of materials and quality, which are inherent to the recycling process and are neither calculated nor reported.

The Current System

At present, although topsides are being removed, much of the subsea infrastructure is being left at sea. Although the structures may be occupied by fauna and flora, they are not purposefully reused as artificial reefs or for other applications such as carbon capture and storage. Materials brought to shore are usually recycled, with steel generally being exported. While recycling overseas allows a reduction of 30% CO2 emissions compared to producing new steel, recycling in the UK would allow a reduction of 50% CO2 emissions, in addition to the creation of local jobs.

The estimation of the quantity of materials being reused is uncertain; however, there is a consensus that it is currently (much) less than 2%. Finally, little goes to landfill, although there is evidence to suggest that several tonnes of materials which could be recycled, such as paper, are being directed to landfill without further justification. So why are reuse rates so low?

Due to several characteristics of the oil and gas industry in the North Sea, such as mature age, deep seabed, and harsh environment, most offshore equipment is bespoke.

Although the reuse and remanufacturing supply chain is established for the operating stage of platforms, this is commonly deemed as a barrier to reuse at the decommissioning stage with examples of the reuse of decommissioned materials scarce.

Decommissioned piping from wells (referred as ‘tubulars’) is, perhaps, the most successful case, as this is continuously reused, particularly in construction.

There is also a perceived lack of demand for materials and equipment recovered from offshore platforms, in turn, due to a perceived lack of confidence in materials sits alongside a lack of equipment standardization and a perceived risk of equipment failure.

Lack of Collaboration, Coordination and Early Info Sharing

Consolidating those barriers, reuse is also stymied by several delays in the flow of information in the current offshore decommissioning system. The analysis of decommissioning plans found that the information submitted on materials and equipment is basic, in general simply the tonnage of each material category. This does not provide useful information for the supply chain for potential reuse.

How to Fill the Glass

Building upon previous studies and upon our analysis, our report proposed interventions to promote collaboration and foster reuse within the decommissioning system, but this is only a piece of the puzzle to create a circular economy in the North Sea.

A circular economy is not simply about reusing, repurposing, remanufacturing, and recycling. Ultimately, the best approaches for the environment are those that reduce the need for materials in the first place. For oil and gas, there is a need to design modular, increasingly standardized equipment and platforms. For existing platforms, the question still unanswered is whether there is a need for decommissioning and the wisdom of the OSPAR 98/3 decision.

We believe the decommissioning of offshore infrastructure should be seen as an opportunity – in particular for Scotland. As one of the first regions in the world to mature and undergo mass decommissioning, there is potential for creating an innovative North Sea industry with skills that can be exported.

It’s time to stop discussing the potential of reuse and focus on delivering the circular economy and all the benefits it can bring for the environment, job creation, and innovation

About the Authors

  • Melissa Marques is a Research Assistant at Heriot-Watt University. Her PhD focuses on investigating value creation and productivity in the context of the circular economy.
  • Umit Bititci is the Professor of Business Performance and the Deputy Executive Dean of the Edinburgh Business School, Edinburgh, UK.
  • Amos Haniff is Dean of the University (Pan-Dean) across Heriot-Watt University campuses in Scotland, Dubai, and Malaysia, and an Associate Professor of Project Management.
  • Matt Blair is Chairman of J+S Subsea, which provides asset support through their Legacy Locker, and Vice-Chair of the Leadership Group of Decom North Sea.