The North Sea is one of the busiest seas in the world, with wind farms being used by fishing, shipping, sand extraction and the production of oil and gas, among other things. Parallel to the further development of offshore wind, important shifts will take place in the North Sea in the coming decades when many oil and gas fields cease production and associated infrastructure is dismantled. This requires a precise and nature-friendly policy. The wind sector is keen to collaborate on this. Also to be able to learn from the knowledge and experience gained in the oil and gas sector. (Photo: Wintershall Noordzee B.V.)
"If we continue at this rate, we will have removed 60% of all platforms in the North Sea in ten years."
Situation of the oil and gas sector
Compared to the total regional North Sea, the size of the Dutch part to be dismantled is relatively small, about 10% of the regional total in terms of tonnage to be removed and platform size. Although there is a good overview of all the infrastructure that needs to be dismantled, the timing is highly dependent on national and international developments.
Last year, eight oil and gas platforms were removed from the North Sea, compared to five in the three years before that. There is movement in the market, writes the FD.
Today, there are still some 150 platforms and interconnected pipelines that produce and transport oil and gas. Many oil and gas fields will eventually cease production when they reach the end of their economic lifespan. The dismantling of infrastructure and the rehabilitation of production and processing sites are part of the normal business cycle, with the operating company responsible for the safe, sustainable and environmentally friendly execution of the work. This is reported by Nexstep, the national platform for reuse and decommissioning of oil and gas platforms, in its Index Report 2024, published on 2 July: ‘Responsible decommissioning’.
Nexstep is a joint initiative of the Dutch state, represented by EBN and the Dutch oil and gas industry, represented by Element NL. The platform's mission is to contribute to the efficient, safe and environmentally friendly reuse and decommissioning of the oil and gas infrastructure in the Netherlands.
Dismantling, reuse and repurposing
Decommissioning includes various activities for wells, installations and pipelines. For wells, this means shutting down and exiting safely. (P&A, or 'Plug and Abandon'). With this technique, the well is secured after completion of operation and permanently closed. This is done by installing (cement) plugs, seals and fluids in the borehole, and cutting the casing under the seabed or land surface, returning the seabed or land surface to its original state.
For offshore installations (platforms), this means cleaning and removing decks, jackets and piles. For land-based installations, this means cleaning and removal, restoring the site to its original state. In the case of pipelines, this involves cleaning and decommissioning, and possibly removing them where necessary.
Reuse means the use of reservoirs, decks, jackets, pipelines and wells for the original purpose (gas and oil extraction) or new purposes. Examples of this are the relocation of offshore platforms to realize other fields.
Then there is also repurposing. This includes the use of reservoirs, decks, jackets, pipelines or wells for alternative purposes, such as CO2 storage, transformer sites for wind farms, power-to-gas (e.g. hydrogen from wind energy) and other renewable or geothermal energy activities.
Process of decommissioning
Decommissioning is usually preceded by several years of careful planning. It involves many steps that involve different stakeholders. The service industry often provides technical and logistical services.
The actual closure of a single well typically takes several weeks, depending on the complexity of the operation. The physical removal of an offshore platform can take weeks to months, depending on the complexity and size of the installations. Restoring a site on the mainland is a longer process and usually takes several months. Foundations, cables and pipelines are removed in accordance with the landowner's wishes before the site is restored to its original state.
The decommissioning activities are subject to national and international legislation to which the operators fully comply. Prior to decommissioning, a work plan must be submitted for approval by the authorities. The competent authority for that purpose shall be the Staatstoezicht op de Mijnen.
Nature-friendly dismantling
Intensive use of the North Sea, combined with climate change, has left nature in the North Sea in a poor state. To ensure the future resilience of North Sea nature, the pressure of human activities must be urgently reduced - 'passive recovery' - combined with active restoration of specific natural forms such as reefs. In the North Sea Agreement, agreements have been made about a coherent approach to the energy, food and nature transition, aimed at achieving a healthy North Sea.
In the North Sea Agreement, agreements have been made about a coherent approach to the energy, food and nature transition, aimed at achieving a healthy North Sea.
The project 'Nature-friendly dismantling of assets in the North Sea' is a joint initiative of EBN, Nexstep, Element NL, Natuur & Milieu, NedZero and the North Sea Foundation. It examines whether, and if so under what conditions, elements of human objects, which would normally be removed – such as artificial reefs or parts of energy installations – can also provide added value to nature in the long term.
The starting points are the techniques used for removal and the assessment of the nature-enhancing value of elements. Project manager of 'Nature-friendly dismantling' Anne-Mette Jørgensen explains that infrastructure can be removed in such a way that it causes as little disruption as possible to the surrounding environment. For example, by loosening components by using vibrations instead of pulling them out of the seabed with brute force.
It is also important to take a good look at the ecological added value of the various elements. For example, it should be better examined which species are present on or near a structure and their influence on biodiversity and the food chain of the surrounding ecosystem. If the conclusion is that parts of a structure have a significant added value for the ecosystem, it could be decided to leave these components permanently in the sea. Provided that this can also be done safely at the location in question. Think, for example, of the substructure of a gas platform or the erosion protection of a wind turbine.
It remains the responsibility of the owner of a structure to remove the remaining parts of the infrastructure in accordance with applicable laws and regulations. If it is decided to leave elements permanently in the sea, this should be done purely on the basis of nature-related considerations.
Samenwerking met wind
"Collaboration reduces costs," says Starink in the FD. In the offshore sector, where everything is by definition large and also expensive, it can save tens and perhaps hundreds of millions of euros when companies' decommissioning jobs fit together seamlessly.
But there are more reasons why the oil and gas sector collaborates with, for example, the wind sector. According to Jørgensen, the oil and gas industry and the wind industry face similar decommissioning challenges.
Both oil and gas installations and wind farms are, in principle, subject to a strict removal obligation, with specific regulations regarding pipelines and cables, Jørgensen explains. Cooperation with the oil and gas sector offers added value for the wind sector, as oil and gas already has a lot of experience in decommissioning infrastructure and reaching agreements with the state on the transfer of long-term responsibilities.
Oil and gas installations, like shipwrecks, can also serve as examples of the expected development of ecological values on and around wind turbines. It is even possible that parts of oil and gas platforms located in the wind farms could play a role in nature-enhancing activities in wind farms in the long term. For the oil and gas sector, cooperation with the wind sector has added value because of the wealth of knowledge within the wind sector. For the oil and gas sector, collaboration with the wind sector has added value because of the wealth of knowledge within the wind sector about nature-enhancing construction.
Long-term responsibility
A crucial element that has not yet been fully worked out is who bears the long-term responsibility for artificial reefs and abandoned infrastructural elements. Under current legislation, the oil and gas companies that own a platform remain permanently responsible for monitoring and maintenance, even after production has ended. But if you want to leave elements permanently in the sea for the benefit of nature, this is not a desirable situation: energy companies are not nature managers and cannot guarantee that they will still exist in a hundred years' time.
Jørgensen explains: "If nature-enhancing objects are left behind after partial dismantling, the long-term responsibility for those objects must be transferred to an independent and 'permanent' body, such as the state. The aim of this project is to explore these types of options, also taking lessons from the mining industry and other countries. The underlying principle will be that monitoring and management should be carried out from the perspective of nature and that the conservation and protection of nature should be the starting point for everything. The responsibility for things that have nothing to do with nature, such as wells, remains unchanged."
Bottlenecks
There is a tight labour market with a shortage of technically qualified personnel, leading to delays in decommissioning projects. The ageing of the workforce poses a risk of loss of know-how. Moreover, the attractiveness of the oil and gas sector is declining compared to the renewable energy sector. The development of offshore wind farms puts pressure on the use of offshore barges and heavy lifting vessels. Cooperation in decommissioning projects can help overcome some of these drawbacks.
Chances
There are also opportunities due to current developments. New equipment for the installation of wind farms can be used for the removal of relatively smaller platforms and jackets in the Dutch sector. By combining assignments, operators can offer flexibility to the market and attract the necessary resources. There is a tendency to move from one-off lifting contracts to larger framework agreements, which offers more flexibility and clarity.
In the UK, the 'North Sea Transition Deal' boosts market capacity through a voluntary commitment to 50% local UK content for new energy transition projects and decommissioning by 2030. This has led to the establishment of new demolition yards. There are also initiatives in the Netherlands to explore a possible demolition yard in Eemshaven. In general, there seems to be sufficient scrapping yard capacity in the North Sea region.
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