Next decade of decommissioning

The UK offshore sector is forecast to spend £16.6bn on decommissioning over next decade, according to the latest figures from the OGUK. Some 1.2mn tonnes of disused oil and gas installations from the North Sea will be brought to shore for reuse and recycling over the 10-year period.

The OGUK’s Decommissioning Insight 2021 report also notes that operators are aiming to set new standards in waste recovery. About 95% of the material from decommissioned offshore oil and gas installations is typically already recycled, but the focus is now moving towards reuse – where component parts, or occasionally whole structures, are redeployed for new purposes with minimal modifications. This avoids the energy and associated emissions needed for cutting up, smelting or crushing components, or making new ones.

Another key aim is to establish the UK as a centre of excellence for decommissioning – an industry that is set for global growth as oil and gas installations around the world reach the end of their useful lives. British companies and workers who have built experience in the North Sea will be in high demand, predicts the OGUK.

The report also shows that while most other industries were in lockdown during the 2020/2021 pandemic, the oil and gas industry carried on, not only supplying the nation with energy but also decommissioning 234 wells and removing 21 platforms as well as more than 50,000 tonnes of other underwater structures. Examples include the Brae Bravo platform, operated by the Abu Dhabi National Energy Company (Taqa). This 36,000-tonne platform, lying 170 miles north-east of Aberdeen, produced 500mn boe over its 33-year lifetime. The structure, weighing over 36,000 tonnes, was sent to Norway, where 95% of its material was destined for recycling or reuse.

According to Joe Leask, OGUK’s Decommissioning Manager: ‘Over the last five years the UK decommissioning industry has improved its efficiency and cut its costs by an estimated 23%. So, we have done better but I think we can still do a lot more.  If operators work together to create larger projects where we get economies of scale, then we can safely drive costs down even more.’ The industry has set itself a target of a 35% reduction in decommissioning cost by the end of 2022.

He continues: ‘Decommissioning is also a key part of the UK’s transition to low-carbon energy and its aim of reaching net zero by 2050. This is partly because the installations being removed tend to be older and so generate more emissions relative to the oil and gas they produce. But it is also because of the growing opportunities for reuse, repurposing and recycling… In the future some assets could be repurposed for new uses such as offshore wind and permanent storage of CO₂ by pumping it deep under the seabed.’

Thialf and Sleipnir heavy lift crane vessels on location at Brae Bravo
Photo: Heerema