scheduled for decommissioning.
When we decommission a refinery, we safely remove the equipment and restore the land. We use expertise from the existing decommissioning industry to help us with this work. However, like much of the oil and gas industry, some of our more complex decommissioning projects take place offshore.
We take time to identify an appropriate solution to decommission an offshore facility, balancing environmental, safety and economic factors. This involves working with a range of specialists to understand what is technically possible and with regulators such as the OSPAR Commission to agree what is acceptable. We also engage with interested parties to ensure that a wide range of implications of the decommissioning process are considered.
Our largest decommissioning activity, to date, has been the preparation for decommissioning our Brent oil and gas field, which lies in the North Sea between Scotland and Norway. Brent has four platforms, called Alpha, Bravo, Charlie and Delta – they and their related infrastructure are scheduled for decommissioning over the next 10 to 15 years.
Decommissioning the Brent field
97%Decommissioning recycling target for Brent topsides
130Approximate number of installations to be decommissioned by the oil and gas industry in the North Sea in the next decade
Decommissioning the Brent field poses several challenges due to the harsh conditions of the North Sea and the age and design of the platforms, which were built around 40 years ago. Brent was constructed to withstand these conditions, with large concrete legs and base structures under the water on three of the platforms. Newer platforms – those built after the mid-1990s – have base structures that can be refloated and towed away at the end of their life.
The preparation for the decommissioning of the four Brent field platforms started more than eight years ago. During this time, Shell has received expert advice and has consulted with more than 180 interested parties. These include fishing communities, environmental organisations and academics. This engagement has been critical to help shape, inform and gain public support for our recommendations submitted to the UK’s Department of Energy & Climate Change (DECC).
An important factor in our decision process is validation by an independent review group of the science that underpins our decommissioning recommendations. The group was established in 2007 and consists of nine eminent scientists.
Offshore platforms tend to consist of a topside – the part above the water – which includes the processing facilities and accommodation. It sits on a supporting structure. In late 2014, Shell submitted a recommendation to DECC to decommission the Brent Delta’s topside and take it ashore for recycling.
The traditional approach to decommissioning is to dismantle the topside at sea piece by piece. Shell’s proposal is to cut the topside free from the legs and remove it in a single lift, using a specialist vessel. It will then be taken to ABLE Seaton Port in Teesside, UK, for dismantling. This method is safer and will use less energy.
Shell has set a 97% recycling target for the topsides – a figure we already achieved when decommissioning the structures at the Shell Indefatigable gas field in the North Sea.
Balancing environmental factors
We continue to work on our recommendations for decommissioning the rest of the Brent field and to consult with parties outside of Shell. Our recommendations will be submitted to DECC when we are confident that the proposals are safe, technically achievable, environmentally sound and financially responsible. They will include details on drill cuttings, pipelines, the concrete legs and the contents of the base structures.
Creating a decommissioning industry
A large number of platforms in the North Sea are scheduled for decommissioning by the oil and gas industry by 2040. The removal and recycling of these installations presents an opportunity for a decommissioning industry to grow in Scotland and north-east England.
Oil & Gas UK, the representative organisation for the UK offshore oil and gas industry, forecasts that more than £40 billion will be spent on decommissioning assets in the North Sea over the next 30 to 40 years. The work on the Brent platforms – as one of the first major UK oil and gas fields to be decommissioned – will enable us and other companies to develop specialist skills and expertise that we can use on decommissioning projects around the world.