Decommissioning – Navigation (Page Under Review)

For information on the impact of Brexit on oil and gas environmental legislation, please refer to the pdf document downloadable from the Home Page.

Key Legislation:

For more detail on the Legislation relevant to this page, please use the following links:

Supporting Legislation:
  • UN Convention on the Continental Shelf 1958

BEIS: Guidance Note for Operators – Offshore Oil and Gas Sector: Update on Marine Planning in the UK

Marine Guidance Note 553(M): Offshore structure decommissioning – This marine guidance note provides guidance for moving offshore installations during the decommissioning process.

Revised Guidance Notes on the Decommissioning of Offshore Oil and Gas Installations and Pipelines  (PDF document)

  • The Guidance Notes are intended to help companies understand their liabilities and the process for approval of decommissioning programmes. They have been updated to take account of both the experience gained since 2006 and the relevant decommissioning provisions in the Energy Act 2008. These Guidance Notes do not yet include requirements of the Marine and Coastal Access Act and Marine Scotland Acts. New BEIS Guidance is pending.
  • This Guidance Note offers an update to the oil and gas sector on the UK marine planning process with a focus on environmental impact assessments (EIAs) associated with decommissioning activities within a marine plan area.
Consent Needed: A Marine and Coastal Access or Marine Scotland Act Licence is required for all decommissioning operations and most operations will include a range of activities requiring licences. Operators will be able to apply for licences for individual activities, or to apply for licences to cover a range of activities. There are also specific marking and notification requirements where concrete installations, footings of a steel installation or a pipeline remain in place (see the Performance Standards tab). Also see the Performance Standards tab for requirements around Safety Zones. Operations Notice 6: Reporting of Offshore Installation Movements the Offshore Major Accident Regulator (OMAR) (then Offshore Safety Directive Regulator (OSDR)) has issued an updated version of Operations Notice 6. This replaces the previous version which was issued by the Health and Safety Executive (HSE).The update provides guidance for reporting of offshore installation movements and has been revised to update contact address details and to account for legislative changes (e.g. EU Directive 2013/30 on safety of offshore oil and gas operations).
How to Apply: The application process for licences under the MCAA and MSA is not yet known. BEIS guidance has been drafted and is awaiting issue.
Who to Apply to: The application process for licences under the MCAA and MSA is not yet known. BEIS guidance has been drafted and is awaiting issue. Any queries in the meantime should be direct to the DECC Oil & Gas Environmental Management Team by email to
When to Apply: The application process for licences under the MCAA and MSA is not yet known.
Navigation and Marking of Remains (where installation or pipeline left partly or wholly in place): Where it is agreed that a concrete installation, or the ‘footings’ of a steel installation, or pipeline should remain in place, the operator must ensure that the position (horizontal datum to be stated), surveyed depth and dimensions of the remains are forwarded immediately to the Hydrographic Office, for inclusion on Admiralty charts. It is the operator’s responsibility to install and maintain navigational aids for any remains of concrete installations that project above the surface of the sea. The nature of the navigational aids to be employed should be discussed with BEIS, the relevant lighthouse authorities and with interested parties such as fishermen and other mariners. Details of the action to be taken to advise mariners and mark any remains should be included in the Decommissioning Programme; the Hydrographic Office should be kept informed.
Drill Cuttings Accumulations:

Drill cuttings accumulations will only be marked on Admiralty charts if it is considered that they present a danger to surface navigation or alter the charted seabed depth significantly. In such cases they would be recorded as a ‘foul’ or ‘shoal depth’. Details of any cuttings piles that may fall into this category should be discussed with the Hydrographic Office.

Safety Zones: A safety zone is a radius of 500 metres established automatically around all offshore oil and gas installations which project above the sea at any state of the tide. Vessels of all nations are required to respect them. It is an offence (under Section 23 of the Petroleum Act 1987) to enter a safety zone except under special circumstances. The zone stays in place during the decommissioning period and only ceases when the structure no longer projects above the surface of the sea. Any doubt about the continuation of a safety zone during decommissioning work should be discussed with the HSE.
Debris Survey: Upon completion of decommissioning operations, appropriate surveys should be undertaken to identify and recover any debris located on the seabed, which has arisen from the decommissioning operation or from past development and production activity. The area to be covered is likely to vary from case to case but the minimum required will be a radius of 500 metres around the location of the installation or any remains. Following the removal of any debris, independent verification of seabed clearance should be obtained. The usual method of achieving this is to engage a fishing vessel to carry out a trawl of the area and to issue a certificate of seabed clearance. Any debris removal activities and any subsequent trawl of the area will need to take account of the presence of drill cuttings.
Ongoing monitoring (where installation or pipeline left partly or wholly in place): If it is agreed that a concrete installation, the ‘footings’ of a steel installation or a pipeline should be left in place, the condition of the remains will have to be monitored at appropriate intervals by the owners. See Decommissioning – Installations or Decommissioning – Pipelines for further information.
Reporting: See the Consent Needed and How to Obtain It tab.
What to do if in Breach of Consent/ Authorisation: Not yet known.
Offshore Inspection: The BEIS (then DECC) Offshore Oil and Gas Environment Unit Enforcement Policy (PDF document) sets out the general principles that Inspectors shall follow in relation to enforcement including prosecution.
Renewal and Variation: Licences will be valid for a maximum period of one year, but operators will be able to apply to renew licences that cover a range of activities.
Alignment for Decom North Sea and Oil and Gas UK UK offshore oil and gas industry trade bodies Oil & Gas UK and Decom North Sea are to align on key areas to deliver a more efficient and effective decommissioning agenda for the North Sea. More information available here.
Decommissioning Delivery Programme

This programme focuses on three key priorities:

  • Cost certainty and reduction
  • Decommissioning delivery capability
  • Decommissioning scope, guidance and stakeholder engagement.
Decommissioning workshop outputs are now available on the NSTA website Decommissioning workshop outputs are now available on the NSTA website. Themes include delivering capability and decommissioning scope and practice.
Growing market for Decommissioning in Norway Growing market for Decommissioning in Norway evident from Oil and Gas UK forecast (link here)
NSTA Decommissioning Strategy North Sea Transition Authority (NSTA) has published its Decommissioning Strategy, the first of a series of strategies that it plans to issue.Further details are available here.