Decommissioning - Navigation

• Petroleum Act 1998
• Petroleum Act 1987
• Marine and Coastal Access Act 2009 (MCAA)
• Marine Scotland Act 2010

Licensing provisions of the MCAA and Marine Scotland Act will come into force in April 2011 and will disapply the Coast Protection Act. MCAA will include navigational provisions, but virtually all activities associated with exploration or production/storage operations will not require licences.

Although most activities associated with exploration or production/storage operations that authorised under the Petroleum Act or Energy Act are exempt, this exemption does not extend to decommissioning operations. The licensing provisions of these Acts come into force in April 2011. A licence will be required for all decommissioning operations and this will include navigational considerations.

• UN Convention on the Continental Shelf 1958

• Revised Guidance Notes on the Decommissioning of Offshore Oil and Gas Installations and Pipelines (pdf file) (March 2011 version 6)

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 DECC Guidance is pending.

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 Performance Standards).

Also see Performance Standards for requirements around Safety Zones.

The application process for licences under the MCAA and MSA is not yet known. DECC guidance has been drafted and is awaiting issue. Any queries in the meantime should be direct to DECC Oil & Gas Environmental Management Team by email to emt@decc.gsi.gov.uk

The application process for licences under the MCAA and MSA is not yet known.

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 DECC, the relevant lighthouse authorities and with interested parties such as fishermen and other mariners. It is the operator's responsibility to ensure the maintenance of any such navigational aids. 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 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 recrded as a 'foul' or 'shoal depth'. Details of any cuttings piles that may fall into this category should be discussed with the Hydrographic Office.

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 m 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.

Not yet known