News Extra: Shell lodges Brent oilfield decommissioning plans with UK Government
01 March 2017
On February 8, Shell submitted proposals to the UK Government involving the decommissioning of all the Brent oilfield installations in the North Sea. The proposals, which run to almost 4,000 pages of highly technical content, will be scrutinised by the Government and other stakeholders over a 60-day consultation period at the end of which ministers will decide whether or not to accept Shell's plans.
Brent A, B, C & D - Image: Shell
The decommissioning of Brent, which has produced oil for 40 years, is one of the most complex engineering projects of its kind and is expected to take a decade to complete. The field, where Shell is the operator and co-owner alongside Esso E&P UK, lies about 110 miles north-east of Shetland and apart from the four platforms, has more than 140 wells, 64 storage shells and 28 pipelines.
Only Brent’s Charlie platform is still in use - Alpha, Bravo and Delta have now shut down. Shell said the platforms and infrastructure had “significantly exceeded” their original life expectations after producing oil and gas for more than 35 years.
Brent decommissioning asset manager Duncan Manning said: "After an extensive and in-depth study period, the submission of Shell's Brent decommissioning programme marks another important milestone in the history of the Brent oil and gas field.
"Shell has undertaken thorough analysis, extensive scientific research and detailed consultation with over 180 stakeholder organisations over the past 10 years.
"Working within the tightly defined regulatory process, we believe that our recommendations are safe, technically achievable, environmentally sound and financially responsible.
"Shell encourages all those with an interest in the decommissioning of the Brent field to review, reflect on and respond to this consultation document."
Shell is asking for permission to leave the giant concrete legs of three of the four Brent field platforms in the North Sea, along with sediment in the storage cells, drill cuttings and heavier pipelines. The lower part of the Alpha platform’s steel jacket would also be left behind.
The company intends to remove the topsides of the four Brent platforms, debris lying on the seabed, and oil residues contained within the concrete storage cells of the gravity base structures.
Interested parties have until April 10 to make any concerns known as part of the 60-day consultation process.
If the UK Department for Business, Energy and Industrial Strategy (BEIS) approves the plans, permission to leave structures behind must be granted by the Convention for the Protection of the North East Atlantic (OSPAR), which stipulates installations must be removed in their entirety once they reach the end of their production cycle.
But exceptions can be made under OSPAR rules for platforms with concrete base structures, which applies to Brent’s Bravo, Charlie and Delta platforms. Shell has said removing the 300,000 tonne concrete legs would be “riddled with safety risks” and had little merit for the environment.
These arguments have been accepted on previous North Sea decommissioning projects, where the risks associated with total or partial removal were deemed unacceptably dangerous for project personnel.
Total’s MCP-01 platform in the northern North Sea, for example, was decommissioned between 2006 and 2009 with its concrete base left in place and the upmost elements standing proud of the sea surface with navigational aids installed.
If Shell is granted an exemption – as expected – it would become one of a select group. According to the BBC, just five exemptions have been issued by OSPAR for 124 installations decommissioned since the rules came into force in 1998.
WWF Scotland director Lang Banks said he accepted the “principle” that companies can ask to leave some materials behind, including concrete legs, if it can be proven that removing them would be detrimental to the workforce and the environment. But he said he would press Shell to do its utmost to remove potentially hazardous materials.
“Oil and gas companies operating in the North Sea have a legal, as well as moral, obligation to clean-up their mess. Having once pushed the boundaries of science and engineering to secure the oil and gas beneath the seabed, the industry should show the same innovation when it comes to decommissioning,” Banks said.
Deirdre Michie, chief executive of industry body Oil and Gas UK, said: "For more than 40 years, Brent has been a leading light in the UK's industrial success story, contributing almost 10% of the region's oil and gas, delivering billions of pounds to the UK economy and supporting tens of thousands of highly skilled jobs.
"Today's announcement opening the consultation for Shell's Brent Decommissioning Plan is another milestone in this story, broadening the reach of public stakeholder engagement that has already taken place, as this iconic field moves into the next stage of its lifecycle.
"Ground-breaking ingenuity was required to bring the Brent field, located in the deep waters of the northern North Sea, into production and these skills will be required into the future as industry seeks to maximise economic recovery of the UK's oil and gas alongside delivering decommissioning in a safe, environmentally responsible, and cost-efficient way."
Oil and Gas UK has previously estimated that more than 100 platforms are expected to be completely or partially removed from the UK and Norwegian continental shelves by 2025. More than 1,800 wells are also scheduled to be plugged and abandoned and 7,500km of pipeline decommissioned.
The organisation suggests it will cost nearly £17bn over the next 10 years to remove around 80 platforms and their associated infrastructure. The estimated cost to complete the entire job through to the 2050s ranges between £30bn and £60bn, a figure that has risen on several occasions as the scale of the task has become clear.
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