Shell Submits Decommissioning Plan for Brent Oil Field
Thursday 9 February 2017
Royal Dutch Shell PLC on Wednesday submitted a comprehensive decommissioning programme covering the planned retirement of the famous Brent oil and gas field in the North Sea to the UK's Department for Business, Energy & Industrial Strategy.
Lying north of the Shetland Islands, the Brent field has been a cornerstone of the UK's oil and gas industry and responsible for pumping out about a tenth of all the oil and gas ever produced in the UK, pumping out 3 billion barrels of oil equivalent since it was launched in 1976.
The Brent field has been groundbreaking in many ways. At one time it had the UK's longest subsea pipeline and in the 1990s was the world's largest oil field to be depressurised. It has even given its name to the oil benchmark that is used to price two-thirds of the world’s internationally traded crude oil.
Currently, Shell owns half of the field with the other half owned by Esso Exploration & Production UK Ltd. Under current legislation, Shell and Esso will retain ownership of and responsibility for any remaining facilities after decommissioning.
When the Brent field was discovered in 1971, it was one of the most significant oil and gas finds made in the UK sector of the North Sea. At that time the expected life span of the field was 25 years at the most.
At its peak in 1982 the field was producing more than half a million barrels a day. Its production that year would have met the annual energy needs of around half of all UK homes.
The field is served by four platforms - Alpha, Bravo, Charlie and Delta - which all have an individual topside which is visible above the waterline, housing the accommodation block, helipad, as well as drilling and other operational areas. The topsides sit on much taller supporting structures, or legs, which stand in 140 metres of water and serve to anchor the topsides to the sea bed.
The field also boasts 154 wells and 28 pipelines.
Work to prepare for Brent decommissioning started in 2006. More than 300 expert studies have been completed and the results analysed and verified by a group of independent scientists. Shell has also engaged with around 400 stakeholders.
Shell has previously said the decommissioning process would be very complex, predicting it could take about one decade to complete.
Production from Brent Delta ceased in 2011 and from Brent Alpha and Brent Bravo in November 2014. Production from the field will continue, via Brent Charlie, for several years to come.
A previous consultation process concerning decommissioning took place in 2015, which covered the removal of the 24,200 tonne topside of the Brent Delta platform. Work on this is already underway with the Brent Delta topside lift expected to take place in the summer of 2017.
The Brent Delta topside will be removed in a single lift operation by the maritime company Allseas, which has developed the world's largest vessel specifically for work of this kind. The topside will be taken to Able UK, a specialised decommissioning company in Teeside, where more than 97% of the material will be reused or recycled.
The comprehensive decommissioning plan for Brent submitted on Wednesday to the Department for Business, Energy and Industrial Strategy, and proposes that the upper steel jacket on the Brent Alpha platform is removed, along with the topsides of all four Brent platforms, debris lying on the seabed, and the attic oil contained within the concrete storage cells of the gravity base structures.
Ideally, decommissioning is seen as a way of removing all trace of an operation, but some closures end up leaving certain equipment and property in place, most commonly underwater, which can help to reduce the vast sums needed to retire the operation and the workload.
Shell said it is recommending that the three gravity base structures, Brent Alpha footings, the sediment contained within the concrete storage cells of the gravity base structures at Bravo, Charlie and Delta, and the drill cuttings piles all remain in place.
"This recommendation will require consultation with and support of the OSPAR Commission, the body established under the OSPAR Convention to protect the marine environment of the North-East Atlantic," said Shell.
OSPAR is made up fifteen governments of the western coasts and catchments of Europe, together with the European Union. The members are Belgium, Denmark, Finland, France, Germany, Iceland, Ireland, Luxembourg, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the UK.
There are a total of 28 pipelines connected to the Brent field, and Shell said it has put forward "a range of options" to "deal" with the infrastructure as part of the programme, including complete removal, cutting and sealing the ends, leaving in place with a covering of rock, and leaving in place after trenching and burying.
A 60-day public consultation will now be held and, once concluded, Shell's recommendations, combined with consultation responses, will be considered by the Department for Business, Energy and Industrial Strategy.
Providing the Department for Business, Energy and Industrial Strategy accepts the recommendations, it will then seek the support for the necessary derogations from the OSPAR Commission on Shell's behalf, the company 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," said Duncan Manning, Brent decommissioning asset manager.
"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," he added.
Shell 'A' shares were down 2.0% to 2,111 pence per share on Wednesday morning while 'B' shares were also down 2.0% to 2,203.50 pence.