Decommissioning - Pipelines

• Petroleum Act 1998

The Petroleum Act 1998 sets out requirements for undertaking decommissioning of offshore installations and pipelines including preparation and submission of a Decommissioning Programme.

Decommissioning proposals for pipelines should be contained with a separate Decommissioning Programme from that of installations.  However programmes for both pipelines and installations in the same field may be submitted in one document.

• Energy Act 2008

Part III of the Energy Act 2008 amends Part 4 of the Petroleum Act 1998 and contains provisions to enable the Secretary of State to make all relevant parties liable for the decommissioning of an installation or pipeline; provide powers to require decommissioning security at any time during the life of the installation and powers to protect the funds put aside for decommissioning in case of insolvency of the relevant party.

• Marine & Coastal Access Act 2009
• Marine (Scotland) Act 2010

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.

• Pipeline Safety Regulations 1996

These Regulations, administered by the Health and Safety Executive (HSE) provide requirements for the safe decommissioning of pipelines.

• Convention on the Protection of the Marine Environment of the North East Atlantic 1992 (OSPAR Convention)

• OSPAR Decision 98/3

The provisions of OSPAR decisions 98/3 do not apply to pipelines.  There are no international guidelines on the decommissioning of disused pipelines.

• Offshore Production and Pipelines (Assessment of Environmental Effects) Regulations 1999
• Offshore Production and Pipelines (Assessment of Environmental Effects) (Amendment) Regulations 2007

Although there is no statutory requirement to undertake an environmental impact assessment (EIA) at the decommissioning stage, a Decommissioning Programme will nevertheless need to be support by an EIA.  The environmental statement (ES) submitted for development consent under the EIA regulations requires the applicant to consider the long term impacts of the development, including decommissioning.  However, in light of the lengthy period of time between the project sanction and decommissioning, the requirement for a detailed assessment is deferred until closer to the time of actual decommissioning and is submitted as part of the Decommissioning Programme.  It will be necessary to address through the EIA the environmental impacts of alternative decommissioning options as part of the Comparative Assessment (as required for the Decommissioning Programme).  The EIA should consider the impacts associated with all activities offshore, inshore and onshore, the impact on climate change and an assessment of energy and resource consumption (where appropriate).

• Offshore Marine Conservation (Natural Habitats &c.) Regulations 2007
• Offshore Marine Conservation (Natural Habitats, &c.) (Amendment) Regulations 2009
• Offshore Marine Conservation (Natural Habitats, &c.) (Amendment) Regulations 2010

These Regulations make provision for implementing the Birds Directive and Habitats Directive in relation to marine areas where the United Kingdom has jurisdiction beyond its territorial sea. The Regulations make provision for the selection, registration and notification of sites in the offshore marine area (European Offshore Marine Sites) and for the management of these sites.  Competent authorities are required to ensure that steps are taken to avoid the disturbance of species and deterioration of habitat in respect of the offshore marine sites and that any significant effects are considered before authorisation of certain plans or projects.  Provisions are also in place for issuing of licences for certain activities and for undertaking monitoring and surveillance of offshore marine sites. The 2010 Amendment Regulations make various insertions for new enactments (e.g. new Birds Directive) and also devolve certain powers to Scottish Ministers.

• Offshore Petroleum Activities (Conservation of Habitats) Regulations 2001
• Offshore Petroleum Activities (Conservation of Habitats) (Amendment) Regulations 2007

Regulation 5 of the 2001 Regulations requires the Secretary of State to consider whether an "appropriate assessment" (known as a Habitats Regulatory Assessment) should be undertaken prior to granting a licence under the Petroleum Act 1998 where a European Offshore Marine Site may be affected by a proposed plan or project. The 2007 amendment Regulations extend this requirement to all UK waters.

• Offshore Chemicals Regulations 2002

A permit will be required under these Regulations for the use and discharge of chemicals during decommissioning.  Permit application will be required using a PON15E (see Decommissioning Chemicals).

• Offshore Petroleum Activities (Oil Pollution Prevention and Control) Regulations 2005

These Regulations require a permit to discharge or re-inject any material contaminated with reservoir hydrocarbons as defined in the Regulations (see Produced Water).

• Merchant Shipping (Oil Pollution Preparedness, Response & Co-operation Convention) Regulations 1998

There is an expectation that the OPEP produced under these Regulations will cover all activities where there is a risk of a hydrocarbon spill, including activities relating to decommissioning.  This may be achieved by the incorporation of decommissioning activities into the existing OPEP or by producing a decommissioning specific OPEP (see Oil Pollution Emergency Planning).

• Convention on International Trade in Endangered Species (CITES)

The cold water coral Lophelia pertusa is known to exist on offshore installations.  If the coral is present and the installation upon which it is located is to be returned to shore it will be necessary to discuss with Defra the requirements of the Convention on International Trade in Endangered Species.

• Waste Management

The disposal of materials onshore must comply with the relevant pollution prevention and waste requirements (see Handling Waste Offshore, Transfer Special/Hazardous Waste, Transfer Controlled Waste, Waste Disposal and Transhipment of Waste).                                               

• Radioactive Substances Act 1993
• The Transfrontier Shipment of Radioactive Waste and Spent Fuel Regulations 2008

Under these Regulations additional authorisation for handling and disposal of radioactive waste may be necessary in certain circumstances (see Radioactive Substances - Use and Radioactive Substances - Disposal).

• Inshore activities

If during decommissioning there are to be activities undertaken in inshore waters, consideration must also be given to the requirements of legislation relevant to that specific geographical area (UK or elsewhere).  Specific requirements should be checked with relevant national authorities prior to decommissioning and where appropriate investigated and addressed during the EIA.

• 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.

Decommissioning Programme

Approval of the Decommissioning Programme from the regulatory authority.

Section 29 of the Petroleum Act 1998 enables the Secretary of State to serve notices requiring the recipient to submit a costed Decommissioning Programme for his approval at such future time as he may direct. The programme (referred to in the 1998 Act as an “abandonment programme”) should contain the measures proposed to be taken in connection with the decommissioning of a pipeline. Equivalent Notices previously served under section 1 of the 1987 Act will continue to be valid.

Other Consents and Permits

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.

A Chemical Permit under the Offshore Chemical Regulations 2002 is also required for the use or discharge of any chemical during decommissioning (see Decommissioning Chemicals)

Decommissioning activity may be incorporated into existing OPEP or a decommissioning OPEP produced (see Oil Pollution Emergency Planning).

If the coral Lophelia pertusa is present on an installation/pipeline located outside territorial waters that is being transported to the UK or elsewhere a CITES certificate will be required from Defra.

Marine and Coastal Access or Marine Scotland Act Licence required for deposit of stabilisation or protection materials related to decommissioning operations (see Decommissioning Deposits)

A Wildlife Licence may be required, depending on specific decommissioning activities being undertaken.

Additional authorisations for radioactive related issues may be required, depending on specific decommissioning activities being undertaken (see LSA and Radioactive Waste).

If there is any likelihood of oil release (reservoir hydrocarbon) during decommissioning of the pipeline, a permit under OPPC will also be required (see e.g. Produced Water).

There are specific requirements around navigation issues under the Coast Protection Act - see Decommissioning - Navigation.

Subsequent to the submission of draft copies of the Decommissioning Programme and the associated periods of consultation, six copies of the final draft copy of the Decommissioning Programme should be sent to the regulatory authority.

In addition to the Decommissioning Programme, Operators must apply for new and/or vary/surrender existing permits/consents following the specific procedures for the individual permits/consents.

The application process for licences under the MCAA and MSA is not yet known. DECC guidance has been drafted and is awaiting issue.

Documents should be marked for the attention of the Head of the Offshore Decommissioning Unit and be addressed to:

The Department of Energy and Climate Change
Atholl House
86-88 Guild Street
Aberdeen AB11 6AR

It is DECCs intention that applications will eventually be administered through the UK Oil Portal.

In addition to the Decommissioning Unit, Operators must apply to the relevant departments/organisations for new or variations to/surrender of existing permits/consents.

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

See: Timing of preparation of Decommissioning Programme

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

Because of the widely different circumstances of each case, it is not possible to predict with any certainty what may be approved in respect of any class of pipeline. Each will be considered on its merits and in the light of a comparative assessment of the alternative options.

Leaving in place

As a general guide the following pipelines (inclusive of any "piggyback" lines that cannot be easily separated) may be candidates for in-situ decommissioning:

• Those which are adequately buried or trenched and which are not subject to development of spans and likely to remain so;
• Those which were not buried or trenched at installation but which are likely to self bury over a sufficient length within a reasonable time and remain so buried;
• Those where burial or trenching of the exposed sections is undertaken to a sufficient depth and it is likely to be permanent;
• Those which are not trenched or buried but which nevertheless may still be candidates for leaving in place if demonstrated by the comparative assessment to be the preferred option (e.g. trunk lines); and
• Those, where exception and unforeseen circumstances due to structural damage or deterioration or other cause, cannot be recovered safely and efficiently.

Judgments regarding the degree of burial or trenching necessary will be undertaken on a case-by-case basis in the light of individual circumstances. Consultees will need to be satisfied that the pipeline is sufficiently buried or trenched below seabed level to avoid obstruction to other uses of the sea. Decisions on the appropriate depth of burial will take account of seabed conditions and other relevant factors but it is expected that burial to a minimum depth of 0.6 m above the top of the pipeline will be necessary in most cases.

Pipelines, which it is agreed can be left in place, should be cleaned, sealed and filled with water.

Removal

Small diameter pipelines, including flexible flowlines and umbilicals which are neither trenched nor buried should normally be entirely removed.

Any mattresses or grout bags which have been installed to protect pipelines during their operational life should be removed for disposal onshore.  If the condition of the mattresses or grout bags is such that they cannot be removed safely or efficiently then any proposal to leave them in place must be supported by an appropriate comparative assessment of the options.

In the case of rock-dump that has been used to protect a pipeline it is recognised that removal is unlikely to be practicable.  It is assumed therefore that rock-dump will remain in place, unless there are special circumstances that would warrant consideration of removal.  If the rock-dump is associated with a pipeline that is being left in place then it would be expected that the rock-dump would remain undisturbed.  If, however, it is associated with a pipeline that is being removed then minimum disturbance of the rock-dump to allow safe removal of the pipeline and the elimination of any seabed obstruction that may result from the presence of the rock, would be expected.

Deferral

In those cases where a pipeline reaches the end of its operational life before other facilities in the field, the Operator should notify DECC’s Offshore Decommissioning Unit that the pipeline is no longer in use.  DECC will send the Operator a Disused Pipeline Notification form requesting details on the status of the pipeline that has been taken out of use.  Upon receipt of this information DECC in discussion with other Government Departments, including the SEMD, DEFRA and HSE, will consider whether a Decommissioning Programme for the pipeline is appropriate at this stage or whether its final decommissioning can be dealt with at end of field life along with the other facilities in the field.

If it is agreed that final decommissioning may be delayed until a more appropriate time, DECC will issue a letter setting out the conditions upon which it is prepared to defer formal decommissioning.  This may include the requirement to carry out remedial work on the pipeline.  DECC will wish to be satisfied that leaving the pipeline in place until end of field life will not prejudice any final decommissioning solution – including complete removal - and that the pipeline will be subject to an appropriate surveying and maintenance regime. 

In cases where decommissioning is deferred, the pipelines concerned are considered to form part of the Interim Pipeline Regime.  (Further details are available on DECC’s Oil & Gas Website).

DECC is obliged to take proper account of the obligations stemming from the Birds and Habitats Directives to protect and conserve the marine environment. A number of offshore sites have been designated as draft or possible SACs (see JNCC website).

Where the Secretary of State considers that there may be significant effect on the conservation objectives, they may require an Habitats Regulatory Assessment to be undertaken.

If this is the case, JNCC will recommend that as competent authority DECC undertakes a screening for a Habitats Regulatory Assessment (SHRA) or a full Habitas Regulatory Assessment (HRA). The ES or PON15 should contain adequate information to enable DECC to undertake the assessment. EU Guidance on Habitats Regulatory Assessment (pdf file) can provide guidance on the process, in particular Annex 2.

Under the Offshore Marine Conservation (Natural Habitats &c.) Regulations 2007, a person commits an offence if he:

• Deliberately disturbs a European Protected Species in such a way as to be likely significantly to affect:
  • the ability of any significant group of animals of that species to survive, breed, or rear or nurture their young; or
  • the local distribution or abundance of that species.

Marine European Protected Species (EPS) include all species of cetaceans, all species of marine turtles and sturgeon.

The onus is on the developer carrying out an activity to (i) assess the likelihood of committing a disturbance offence (ii) consider the need for mitigation measures and (iii) decide whether to apply for a Wildlife Licence.

A description of the assessment of the likelihood of committing a disturbance offence must be included in the PON14A application. Guidance on undertaking such an assessment is included in the JNCC's Guidance (see Guidance) .

The JNCC has also issued detailed guidance notes for seismic operations, use of explosives and piling operations. These are available on the DECC website.

The Public Participation Directive (PPD) requires a number of aspects of public notification and consultation:

• An outline of main alternatives (if any) should be included in permit applications;
• The public should be notified and made aware of any decisions making available relevant consents and permits with the reasons and considerations on which decisions have been based;
• Public notification at the earliest possible time where the information can be provided on the nature of possible decisions; and
• Making available within applicable timeframes the necessary reports, advice issued to the regulator in accordance with legislation when applications were made and information relevant to a decision which only became available after advertisement of an application.

Discussions should commence well ahead of forecast cessation of operations. As pipelines vary significantly in size and length, DECC advice should be sought at an early stage where the decommissioning does not form part of platform decommissioning.

At a mutually agreed time, following preliminary discussions, the operator should submit to DECC 23 copies of a first draft of a Decommissioning Programme. Copies of the draft programme will be distributed by DECC to other Government Departments and Agencies. Submission in CD ROM form is the preferred method, although one paper copy will also be required. Four paper copies will be required when the holders of section 29 notices are directed formally to submit the Decommissioning Programme.

On receipt of a first draft of a Decommissioning Programme, the Offshore Decommissioning Unit will circulate it for consideration by others with an interest within DECC and to other Government Departments.

At the same time DECC will agree with the operator a timetable for considering the draft programme and submitting it for approval by the Secretary of State. DECC will use its best 10 weeks.

The Offshore Decommissioning Unit will act as a one-stop-shop, co-ordinate all comments on the draft and submit a written response to the operator. Further meetings with Government Departments may be necessary at this stage to discuss whether additional information and amendments to the draft programme may be necessary. 

It is important that sufficient time is allowed for the proper consideration of the proposals in a Decommissioning Programme.  In the majority of cases only one draft of the Decommissioning Programme will be necessary.

At the point at which the draft Decommissioning Programme is submitted to DECC, the Operator should commence statutory consultations as required under section 29(3) of the Petroleum Act 1998. These consultations will be with the representatives of those parties who may be affected by the decommissioning proposals such as the fishing industry. Details of the statutory consultees will be specified in a in a letter containing a notice issued under the Section 29 of the Act. A list of the parties contained in an annex to the Decommissioning Guidance Notes (see Guidance). The Statutory Consultees should normally be given 30 days in which to comment.

The operator will also be asked to announce its proposals by placing a public notice in appropriate national and local newspapers and journals and to place details on the Internet. This notice should indicate where copies of the draft Decommissioning Programme can be viewed and to whom representations should be submitted. A standard Form of Notice including appropriate publications can be provided by DECC. Hard copies of the draft programme should be made available at the Operator's offices and a copy can be placed on the Internet. At the same time DECC will indicate on it’s website that the Decommissioning Programme has been issued for consultation.

The results of consultations should be reviewed with DECC and reported in the Decommissioning Programme when it is submitted for approval. This can be best achieved by appending to the programme the correspondence with interested parties and by indicating the extent to which their views have been taken into account.

A Decommissioning Programme will typically contain the following sections:

Section 1 – Introduction
Section 2 – Executive Summary
Section 3 – Background Information
Section 4 – Description of Items to be Decommissioned
Section 5 – Inventory of Materials
Section 6 – Removal and Disposal Options
Section 7 – Selected Removal and Disposal Option
Section 8 - Wells
Section 9 – Drill Cuttings
Section 10 – Environmental Impact Assessment
Section 11 – Interested Party Consultations
Section 12 - Costs
Section 13 - Schedule
Section 14 – Project Management and Verification
Section 15 – Debris Clearance
Section 16 – Post Decommissioning Monitoring and Maintenance
Section 17 – Supporting Studies
Section 18 – Structure of Combined Decommissioning Programmes

Where it is proposed that a pipeline should be decommissioned in-situ, either wholly or in part, then the Decommissioning Programme should be supported by a suitable study which addresses the degree of past and likely future burial/exposure of the pipeline and any potential effect on the marine environment and other uses of the sea. The study should include the survey history of the line with appropriate data to confirm the status of the line including the extent and depth of burial, trenching, spanning and exposure.

The Environment Agency (in England and Wales) and the Scottish Environment Protection Agency (in Scotland) are responsible for administering and enforcing the waste management controls. 

Anyone who deposits, recovers or disposes of waste must do so in compliance with the conditions of a waste management licence, or within the terms of an exemption from licensing, and in a way, which does not cause pollution of the environment or harm to human health. Any Operator planning to carry out any decommissioning or an associated activity involving waste should contact the relevant Agency. The Agencies are finalising separate guidance for industry on the treating, keeping and disposing of wastes at the decommissioning stage. This guidance will be available from the Environment Agency and the Scottish Environment Protection Agency. 

The disposal of materials onshore must comply with the relevant pollution prevention and waste requirements (see Handling Waste Offshore, Transfer Special/Hazardous Waste, Transfer Controlled Waste, and Waste Disposal).        

Movements of waste from the UKCS to other Member States and Non-Member States are deemed to be a transboundary movement and therefore subject to transfrontier regulations (see Waste –and Transhipment of Waste).

There are specific requirements for Hydographic Office notifications and marking of remains - see Decommissioning - Navigation.

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 Debris monitoring may be required up to 100 m either side of a decommissioned pipeline over its whole length.

Following the removal of any debris, independent verification of seabed clearance should be obtained. Following the removal of any debris, independent verification of seabed clearance will be required. The advisability of over-trawling will be considered on a case-by-case basis and will be dependent upon the extent of any cuttings piles and any other relevant circumstances.

In addition to debris surveys, a post-decommissioning environmental seabed sampling survey should be undertaken to monitor levels of hydrocarbons, heavy metals and other contaminants in sediments and biota.

A survey strategy should be developed in consultation with DECC who will in turn take advice from other Government Departments and Agencies with an interest such as the Fishery Departments. Details of the survey strategy should be included in the Decommissioning Programme.

In addition to the debris clearance and environmental survey requirements described above, where pipelines are left partly or wholly in situ additional monitoring requirements will be required as described below.

Pipelines decommissioned in-situ will be subject to a suitable monitoring programme agreed with DECC in consultation with other Government Departments. Details should be specified in the Decommissioning Programme. The form and duration of the monitoring programme will depend upon the prevailing circumstances and if necessary will be adapted with time. 

At the conclusion of decommissioning operations the Operator will be required to satisfy DECC that the approved Decommissioning Programme has been implemented.  This will involve the submission of a close out report within four months of the completion of offshore work.  This report will include results of the debris clearance and post decommissioning surveys.

The report should explain major variations from the decommissioning programme and should summarise the following:

• Information on the outcome of the decommissioning programme as a whole.
• An explanation of any major variances from the programme.
• The results of debris clearance and any monitoring undertaken.  Any independent verification (e.g. seabed clearance certificates) should be attached.
• The results of the post-decommissioning survey.  If necessary update the schedule for future monitoring or monitoring of items left in place with reasons for the changes.
• Measures taken to manage the potential risks arising from any legacies, including participation in the Fisheries Legacy Trust Company, confirmation of marking any remains on mariners charts, inclusion in the ‘Fishsafe’ system and installation of navigational aids.
• Provide high level summary of actual costs and a general explanation of any difference against forecast costs.

Inspection reports (as agreed with DECC) should be submitted to DECC Offshore Decommissioning Unit, together with proposals for any maintenance or remedial work that may be required.

There may be a requirement to conduct further environmental seabed surveys subsequent to the decommissioning of the pipeline.

Where a pipeline has been left in situ there is a requirement to undertake a monitoring programme (see Snippets).

Experience to date highlights the advantage of commencing cleaning operations early in the decommissioning process.  In addition to cleaning hydrocarbons reasonable endeavours to remove wax and other contaminants, particularly where a line is to be decommissioned in place, will be expected.  Guidance on cleaning topsides and pipelines prior to decommissioning has been developed through the Pilot Brownfields Initiative.  This is available from the Oil & Gas UK website (pdf file).