Net Zero and Decommissioning

What are some of the major issues we face surrounding emissions during the late life of a platform? 

Greenhouse gas (GHG) emissions generally increase during the late life of an asset, as more effort is required to produce hydrocarbons. This, combined with tighter caps on emissions since Brexit, under the new UK ETS, carbon costs are increasing. This has the potential to push assets towards cessation of production (CoP) earlier than originally planned. 

The North Sea is an ageing basin and overall production is in decline, however emissions and cost savings can be recognised during late life by optimizing the topsides operating strategy. At Xodus we are experts in this area and our Emissions Team have developed an emissions reduction tool to pin-point exactly what can be done to align operations with Net Zero expectations. 

  1. How do we account for any emissions once production has ended? 

The emissions following CoP are covered under a Decommissioning Programme. They would normally account for the direct emissions from vessel use offshore and indirect or lifecycle emissions associated with the waste materials taken to shore. There are also emissions associated with replacing any otherwise recyclable materials which are decommissioned in situ, for example pipelines and jacket footings, where this is the likely decommissioning scenario. 

With multiple parties involved it can take some time to bring all of this information together. Given the focus towards Scope 3 (lifecycle) emissions, we really need to look at whether we are accounting for everything that may be required for the reporting of these. Transparency is key for regulatory, shareholder and public perception. 

  1. Where do the majority of the decommissioning emissions actually come from? 

Vessel use is a big contributor where a large amount of material is being removed and transported to shore, but the major contributors are around the lifecycle emissions and this is mainly due to the re-manufacture or recycling of steel components using emissions-intensive coal-based methods.  

There are other contributors that are not currently considered in the Guidance, like methane release during depressurisation and the potential release of carbon from the seabed (which is a major natural carbon sink) if you disturb the top layer of the sediments.  We’re keeping an eye on legislation and guidance changes in the emissions space as these are just some of the emissions sources that will most likely need to be considered throughout the development, operational and decommissioning stages of an asset. 

  1. What does the future look like for decommissioning emissions? 

Getting a grasp of what should be accounted for and what the boundaries of the ‘decommissioning emissions’ picture should look like is essential. The current guidance is over 20 years old now and we really need to think about updating this in a Net Zero context. It’s likely that GHG emissions will be reportable in future by all companies (including the supply chain) so making this a straight-forward and transparent process is essential. 

At Xodus we believe there are a lot of practical things that can be done right now to minimise emissions. Planning and communication early in the decommissioning process is essential. This can identify vessel sharing opportunities and campaigning synergies. Technological development and potential for the use of ‘cleaner’ vessels and UAVs, and cleaner approaches to recycling are also key to realising emissions savings.  

Decommissioning activity is only going to increase in the coming years so we need to make sure we get it right from the start if we want to make a significant contribution to the Net Zero journey. 

Published Date
03 Apr 2022
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