Brent Spar

Initial decommissioning ideas

The Brent Spar was taken out of operation in 1991 after some 15 years' service in the Shell/Esso Brent Field in the northern North Sea - the UK's biggest source of oil and gas. A very large floating oil storage and loading buoy, the Spar had stored oil from the Brent 'A' platform and acted as a tanker loading facility for the whole of the Brent Field.

With these constraints in view, detailed studies by several independent companies established that deepwater disposal of the Spar at a site in the deep Northern Atlantic was the Best Practicable Environmental Option (BPEO). The UK Government publicly approved this original plan in February 1995, and also informed the European Union and the twelve countries in continental Europe who are signed up to the Oslo Convention for the protection of the marine environment.

The inventory carried out by Shell as part of the original BPEO showed that the Spar was not at all the "toxic time-bomb" subsequently alleged. Its deepwater disposal would have had negligible impact on the marine environment and this was confirmed by independent scientists and oceanographers, and supported in consultations with environmentalists, conservationists and fishermen. The integrity and professionalism of this original inventory was endorsed by the international safety foundation, Det Norske Veritas, who carried out a further independent audit of the Spar's contents for Shell in Norway towards the end of 1995.

Safety considerations are also a vital element in the assessment of a BPEO, and in comparison with deepwater disposal, the safety risks in terms of fatalities during onshore disposal were calculated to be some six times greater.

However, these scientific and risk evaluations were largely swept aside in the exceptional events of the summer of 1995, when outrage against deepwater disposal of the Spar arose in many people from a deeply rooted belief in the principle of "clean seas". Shell abandoned the deepwater disposal plan on 20th June 1995. The UK Government accepted this course of action and helped Shell to obtain a licence from the Norwegian authorities allowing the Spar to be anchored in the deep waters of Erfjord.

At the same time the UK Government made it clear that, until demonstrated otherwise, the BPEO for the Spar would remain deepwater disposal. Shell UK engaged in an open, wide-ranging initiative to find the solution which would match or better deepwater disposal - an initiative which had consultation, dialogue and high profile public examination as central features. The programme was called "Our Way Forward".

Suggestions for the disposal of the Spar were invited. A notice was placed in the Official Journal of the European Communities inviting expressions of interest from major contractors. In the months up to early 1996, we received some 400 letters suggesting many imaginative solutions for the Spar. They ranged from removing the topsides to shore for use as a training facility to creating a fish-ranch within the submerged tanks, or using the Spar's unique dimensions to harness wave power and generate electricity.

Practically underpinning our search for a solution was a unique contracting process put in place in October 1995. Typically a company invites contractors to bid for a specified solution, but in the case of Brent Spar, Shell did not know what the final disposal option would be. The process consequently required contractors to compete to find and develop the best solutions. Shell awarded the implementation contract to Wood-GMC. Their plan to re-use the Spar's hull to build a quay in Norway was considered the BPEO. The decision process harnessed not only the expertise of the major contractors with all their different resources, but also the ingenuity of the many entrepreneurs who contacted Shell.

The Brent Spar project was effectively completed on 10 July 1999 when cut and cleaned ring sections of the buoy's hull were placed on the seabed at Mekjarvik, near Stavanger, in Norway to form the base of a new quay. In all the project took 330,000 man hours (200 man years) to complete. Surprisingly, a large amount of cold water coral - normally found further north and in deeper waters - had built up on the Spar's underside. Costs were much higher than was estimated. Unexpected technical, environmental and safety challenges helped to bring the dismantling project figure to £41 million from an original estimate of £21.5 million. Including the cost of the original aborted deep sea disposal project, the total cost of decommissioning Brent Spar was £60 million. The work was completed without injury to any of the workforce and without impact on the local environment.

If the exceptional events surrounding Brent Spar have achieved a good outcome, we hope it has been to place such difficult environmental choices and the contribution science can make to finding solutions at the forefront of many more minds. We will continue to defend the balanced approach to environmental decisions in the belief that it is in the vital interest of our economies, our societies and the environment. But we will also pay much more attention to listening to and consulting people about the many issues involved and to gaining their confidence and trust.

Brent Spar became not just a North Sea installation, but a unique and defining event. The challenge now is to ensure that it defines a new stage in the regulation of business activity that enjoys the popular support of hearts as well as minds.