Removing Oil Rigs from the North Sea – is Europe up for the Challenge?

Emily Callahan and Amber Jackson dive Platform A376 during a research cruise in the Gulf of Mexico, home to the oldest and most successful Rigs 2 Reefs programs in the world. Photo Courtesy of James Wiseman

The standards and rules for decommissioning offshore oil rigs are firmly established in the North Sea. When an oil platform is no longer economically viable, it must be removed. There is to be no dumping and abandoning these structures at sea. Save for substructures heavier than 10,000 tons, the bottom (so-called ‘footings’) of these structures may be left in place. Why is this significant? The majority of these installations were never designed to be removed and the required decommissioning is of a scale and complexity not yet witnessed before in the world of offshore oil and gas. The imminent decommissioning of over 500 platforms in the next few decades presents a daunting challenge to Europe. How to reverse-engineer the removal of hundreds of steel structures, some of which rival the size of the Eiffel tower and are located in deep and turbulent waters, while maintaining safe and cost effective strategies. Another challenge is that unlike the US, northern Europe’s shared body of water, the North Sea, spans the exclusive economic zone of 7 countries and thus forces an international standard that all must agree on. This ‘international standard’ will become a crucial factor in determining the success or failure of all future decommissioning projects in the North Sea.

Offshore Oil and Gas Fields under Exploitation in the North Sea
Offshore Oil and Gas Fields under Exploitation in the North Sea, OSPAR’s Quality Status Report, 2010 (

I had the opportunity to engage in and discuss these issues when my research partner, Amber Jackson, and I traveled to meet with LINSI (The Living North Sea Initiative) in Amsterdam, and presented at DOSS (a conference on the decommissioning of Offshore Subsea Structures) in Glasgow, Scotland. Hundreds of North Sea platforms face removal, under often dangerous and risky conditions, and coupled with mounting costs of varying uncertainty, means that total compliance under OSPAR (named because of the original Oslo-Paris conventions for the Protection of the Marine Environment of the North-East Atlantic) may not be the best answer. We encountered these themes over and over again during our time in Europe. OSPAR is the primary mechanism governing the North Sea region, by which fifteen Governments of the western coasts of Europe, together with the European Union, cooperate to protect the marine environment of the North-East Atlantic. The decommissioning of oil and gas assets is primarily governed by the Petroleum Act which implemented OSPAR Decision 98/3. The act requires licensees to pay for offshore installations to be properly decommissioned; in most cases it effectively mandates complete removal from the seabed. In other words, the potential to allow platforms to be relocated or left in place to function as artificial reefs is slim, and in light of historical events that lead to public outcry, such as 1995’s Brent Spar decommissioning and the BP Oil Spill of 2010, unlikely (Jørgensen, Dolly).

So why not develop a Rig to Reef program in the North Sea? As demonstrated in other areas of the world, Rigs to Reefs offers a viable, and perhaps more environmentally and economically feasible option. The water in the North Sea is cold, murky and incredibly nutrient rich, and home to a wide variety of commercially viable marine life. The bottom is littered with one of the highest concentration of wrecked ships in the world, a grim reminder of the violent power of this icy water body. When paired with the vast array of hard substrate provided by the platforms- these nutrient rich waters have fostered an abundance of marine growth similar to what we have found on California’s platforms (Callahan, E.). They may be home to more than over 100 different marine species, including some cold water coral species such as Lophelia pertusa, one of six coral species known to form extensive cold-water reefs, and unlike most warm-water corals, it lacks symbiotic algae and thus does not require light.

Image courtesy of Joop Coolen, From his Biodiversity and multifunctional use of old production platforms and new offshore wind farms project, for more information please visit:
Image courtesy of Joop Coolen, image of a North Sea platform, from his research project on the Biodiversity and multifunctional use of old production platforms and new offshore wind farms, for more information please visit:

For the North Sea strict compliance, leading to the total removal of the platform, may not be the best answer and for many stakeholders, the debate over decommissioning has come at just the wrong time. The combination of aging assets, high exploration costs, and a significant drop in oil prices is just the troubling dilemma Europeans had hoped to avoid. Currently, there are 1357 offshore installations that are operational in the OSPAR maritime area, most of which are sub-sea steel installations (726) and fixed steel installations (545). These ‘fixed steel’ installations are the only candidates that may be eligible for ‘reefing’ as part of a yet to be created “Rigs to Reefs” program. When considering the vast number of these ‘fixed steel installations’ that reamain, reefing is an option that should be seriously considered. However despite this, there is a positive side. This dilemma could pave the way for creating a standard of excellence in the North Sea for decommissioning practices and though the North Sea may be one of the first harsh, cold water marine environments requiring extensive decommissioning, from a global perspective, it certainly won’t be the last.

Image Courtesy of OSPAR Commission, Assessment of impacts of offshore oil and gas activities in the North-East Atlantic", 2009. Offshore Industry Series
Image Courtesy of OSPAR Commission, Assessment of impacts of offshore oil and gas activities in the North-East Atlantic”, 2009. Offshore Industry Series

In total, the estimated cost of decommissioning in the North Sea has been determined to be in the order of one-hundred billion dollars, a number not for the feint of heart. Developing and implementing a “Rig to Reef” program could potentially save 10% of these looming costs. Europeans stand at a critical crossroad. Decommissioning will represent huge incremental costs over the lifespan of the production field, and more than half of those costs will be incurred by governments through tax relief schemes, whereby taxpayers become the main shareholders in a business most are hardly aware of. Rigs to Reefs may just be the answer to the mounting costs and risks facing the decommissioning of structures in the North Sea and will likely be the important first step towards a series of Rigs to Reefs programs around the world.


Banks, Ken. “Offshore decommissioning ‘a new beginning for North Sea industry’, BBC Scotland North East reporter)

Bousso, R., Schaps, K. “Oil Firms May Retain Clear-Up Costs for Hard-to-Sell N. Sea Assets”. Reuters. July 21st, 2015.

Callahan, E. “Harvesting the Unlikely Fruits of Oil and Gas”, National Geographic Ocean Views, Jan. 14th, 2015. (

Coolen, Joop. “Biodiversity and multifunctional use of old production platforms and new offshore wind farms”.

Dooley, Kenny. “Decommissioning time”. July 2nd, 2015. Oil Online. (

Jørgensen, Dolly. “OSPAR’s exclusion of rigs-to-reefs in the North Sea”. Ocean and Coastal Management 58 (2012):57-61.

OSPAR Commission. “2015 Update of the inventory of Oil and Gas Offshore Installations in the OPSAR Maritime Area. (

Changing Planet


Meet the Author
Emily is an oceanographer, explorer and marine environmental scientist. In 2011 she worked in the Gulf of Mexico on the Deepwater Horizon oil spill. Her work in the Gulf analyzing the oil spill, and the development of the oil and gas industry sparked her research interest in the Rigs-to-Reefs program. Emily has a masters in marine biodiversity and conservation from Scripps Institution of Oceanography, and is currently a marine scientist for an environmental consulting group and managing partner and explorer at Rig2Reef Exploration