Facilities Decommissioning

UKCS Facilities Decommissioning Scope Forecast

Offshore facilities scope represent 55% of the estimated UKCS decommissioning costs (or £28bn) once owner’s costs, equipment disposal and site remediation costs are considered.

Further ramp-up of activity and associated spend is expected in the 2020’s with high levels of spend continuing throughout the 2030’s.

The largest component of the facilities decommissioning spend is for the platform removals and subsea decommissioning (clean up and conditioning, potential removals and site remediation).

Another significant area of spend is that of the ‘owner’s cost’ which includes the cost of keeping safe and operating the offshore installations after cessation of production and during the decommissioning operations (P&A and facilities preparation).

Technology innovation to support industry best practise has a key role in helping industry reduce the cost of decommissioning over the entire process.


UKCS decommissioning cost breakdown (2019)

UKCS decommissioning cost breakdown (2019)

UKCS decommissioning spend outlook

UKCS decommissioning spend outlook

Sources: OGA UKCS Decommissioning Cost Estimate 2020

Count of technologies (Operators plans, total 884)

The Facilities Decommissioning category has consistently attracted the least number of technology solutions reported by Operators. While the low number of reported technologies to some extent reflects a very focussed area of technology application, it would appear contrary to the significant scope and spend forecast for decommissioning in the UKCS over the next 10 to 20 years.

Operators technology focus (2020)

facilities decommissioning bar chart 4

Facilities decommissioning (39)

facilities decom pie chart 1

Operator submissions were analysed according to six categories as follows:

Technology Sub-Categories
8.1 Data & Planning
8.2 Late Life Mgmt & Equip Readiness
8.3 Topsides/Jackets Decomissioning
8.4 Subsea Equipment Decomissioning
8.5 Site Inspection & Monitoring
8.6 Waste Mgmt & Recycling


Subsea Equipment Decommissioning is the main area of focus followed by Topsides/Jackets Decommissioning, both of which are high cost areas.  Notable areas of focus include:

  • Earlier conversion to NUI status by employing alternative power generation to reduce facilities manning requirements
  • More cost efficient methods of lifting and transportation of Topsides and Jackets
  • More efficient methods of cutting and removal of structural members
  • Innovative subsea facilities removal techniques to allow diver-less operations and use of lower cost vessels

Technology Spend on Facilities Decommissioning was £9.2 MM representing 5% of the total of the technology budgets reported by operators with only 9 operators reporting spend on Facilities Decommissioning technology.


Further Information



Technology maturity (Operators plans)

Operators are predominantly looking to Existing Technology to meet Facilities Decommissioning needs with little to come by way of technology at Early Commercialisation.  Similarly to Well P&A, a greater proportion of technologies currently either in early or late stages of development were referenced by operators.

facilities decommissioning pie chart 2


Technology delivery (Operators plans)

The supply chain is the dominant provider of technology solutions for Facilities Decommissioning with nearly 60% coming directly from vendors and Supplier Partnership arrangements bringing the supply chain involvement to 77%.

With operators reporting a fewer number of technologies addressing Facilities Decommissioning, Net Zero Technology Centre managed programmes play a greater role in technology delivery in this category than most others. Ongoing projects are addressing subsea removal (laser cutting, buoyancy lifting and in situ accelerated corrosion) alongside surface facilities lifting and transportation.

facilities decommissioning pie chart 3

Technology Sub-Categories

Late-life management & equipment readiness

Operators are focusing on two main areas to manage the late life of their assets and ensure readiness for decommissioning:

  • a) maintain safety and repairs needed to facilities in a cost efficient manner


  • b) reduce Opex of non producing platforms, transitioning to NUI status with alternative power generation.

Technologies such as walk to work for improved access from work vessels to platforms during decommissioning are also reported by several operators.


Number of technologies by operator

facilities decommissioning pie chart 4

Technology maturity​

2 - Existing Technology (40%)
2 - Early Commercialisation (40%)
1 - Undefined (20%)

Application Exemplars​

Existing Technologies:
  • Composite repairs of platform fabric are more cost efficient than welding or new onshore fabrication (Chrysaor)
  • Virtual Guard Ship - Platform hosted transponder to create "ghost" entity above subsea infrastructure can save the cost of Nav aids or standby vessel (Apache)
  • Walk to Work modular gangway to allow access between Construction Vessels and platforms increasing crew efficiency and reducing helicopter logistics (CNR)
  • Low cost autonomous Aids to Navigation, Solar powered LED Nav Aids from renewables industry seek to reduce costs during unmanned operating phase (CNR)
Emerging Technologies:
  • Alternative Power Generation – combination of wind power, solar, wave and storage to power platforms in cold stack mode.

Topsides / Jackets decommissioning

Operators are looking to deploy technologies such as to reduce the cutting time and combine the cutting and removal using buoyant lifting and recovery systems in the preparation of facilities for removal.  The lifting of topsides and jackets by single lift vessels is reported alongside new innovative solutions under early stages of development such as Accelerated Corrosion Techniques.

Number of technologies by operator

facilities decommissioning pie chart 5

Technology maturity

6 - Existing Technology (50%)
5 - Late Development/Pilot (42%)
1 - Early Development (8%)

Application Exemplars​

Existing Technologies:
  • Increasing load capacity for single lift of heavier structures - 10,000 t now possible with Sleipner and Pioneering Spirit (Chrysaor/CNR/Enquest/Shell)
Emerging Technologies:
  • External Flotation system – Jacket + Topsides Lifting and Transportation system (Repsol Sinopec)
  • Laser cutting for decommissioning, Net Zero Technology Centre project to trial laser cutting on Platform structural members (Net Zero Technology Centre/CNR)
  • Accelerated Corrosion techniques: decommissioning using accelerated corrosion processes on subsea structures (Repsol/Ithaca)

Subsea equipment decommissioning

Operators are using innovative technology in the preparation of facilities to be left in situ, such as pipelines and flowlines, and the technologies to cut and lift subsea equipment such as the above seabed sections of  Conductors and Pipeline bundles from the seafloor and recover safely and efficiently, and disconnecting risers and pipeline flanges using unmanned techniques.

Number of technologies by operator

facilities decommissioning pie chart 6

Technology maturity

11 - Existing Technology,
8 - Early Commercialisation,
4 - Late Development / Pilot,
2 - Early Development,
8 - Undefined

Application Exemplars​

Existing Technologies:
  • ROV operated Flange Bolt Cutter for unmanned pipeline/riser flange separation Subsea ROV deployed tool cut through flange bolts enabling pipeline / riser to be separated (CNR)
Emerging Technologies:
  • Innovative Conductor Cutting & Dedicated Section Recovery basket removal using innovative buoyant lifting system controlled by a work class ROV (Net Zero Technology Centre/EIP)
  • Innovative Conductor Cutting & Dedicated Section Recovery basket removal using innovative buoyant lifting system controlled by a work class ROV (Net Zero Technology Centre/EIP)


Functional Categories


The technologies referred to in this report are for illustrative purposes only and other technologies may be available. The OGA does not directly or indirectly endorse, recommend or guarantee any entity, product or technology referred to in this report.