Decommissioning vessel at work on North Sea platform
Non-specialist readers, suppliers, trainees, local businesses · 9 min read

North Sea decommissioning in plain English

Image: Vantage Subsea image library / Offshore imagery

A simple guide to installations, wells, pipelines, removals, reuse, port handling and why decommissioning matters to the UK marine economy. With real numbers.

The scale of the work

  • OEUK forecasts £19.7bn in decommissioning expenditure over the next 10 years.
  • Approximately 2,100 North Sea wells will be decommissioned — around 200 per year.
  • Average well decommissioning cost: £7.8 million.
  • In 2021, 10% of UKCS oil and gas expenditure went to decommissioning. This rose to 14% in 2022 and is set to reach 19% by 2031.

What decommissioning means

  • Offshore decommissioning is the process of safely taking late-life oil and gas infrastructure out of service.
  • Work can include wells, topsides, jackets, subsea infrastructure, pipelines, onshore terminals, waste handling and environmental documentation.
  • The work is highly regulated and often planned years ahead through formal decommissioning programmes.
  • Over 75% of spend will be in central and northern North Sea — benefiting ports and communities from Teesside to Aberdeen.

Terms worth knowing

  • Topsides: the upper working part of an offshore platform.
  • Jacket: the steel support structure beneath many fixed offshore platforms.
  • Plug and abandonment (P&A): the process of making wells permanently safe.
  • Comparative assessment: evaluation of options for dealing with infrastructure such as pipelines or subsea equipment.
  • Heavy-lift vessel: a vessel designed to remove large offshore structures in single lifts.