Well Plugging & Abandonment

UKCS Well P&A Scope Forecast 

Well P&A represents circa 45% of UKCS decommissioning costs, or an estimated £23bn spend over the life of the basin.

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

Data related to the past few years suggest a high degree of variability in the cost to P&A individual wells with no clear efficiency trends establishing.

Technology best practice and innovation has a key role in helping operators reduce the cost of well P&A, with an opportunity to develop efficient solutions over the next 2-5 years to be able to capture the expected activity ramp-up.

UKCS decommissioning spend outlook

UKCS decommissiong spend outlook

UKCS decommissioning cost breakdown (2019)

UKCS decommissioning cost breakdown (2019)


Well P&A cost trends

Well P&A cost trends​Platform well P&A cost (NNS/CNS)


Subsea well P&A cost (NNS/CNS)


Sources: OGA UKCS Decommissioning Cost Estimate 2020 and Benchmarking Report 2020


Count Of Technologies (Operator plans, total 884)

The Well Plugging and Abandonment category has the second lowest number of technologies reported (49 discrete submissions accounting for 6% of the total).

well plugging abandonment bar chart 1

Well P&A (49)

well plugging abandonment pie chart 1

The returns were analysed based on the following six sub-categories:

Technology Sub-Categories
7.1 Data & Planning
7.2 Well Inspection & Cement Condition
7.3 Conductor Removal
7.4 Barriers, Placement & Verification
7.5 Tubing & Casing Removal
7.6 Intervention Equipment

Decommissioning cost reduction is a key aim of many of these technologies through assisting planning of P&A campaigns, improving safety and operational efficiency, assessing existing cement barrier element quality, providing solutions for complex abandonment and development of barrier solutions that are compatible with rigless deployment.  Isolation barrier element technology is clearly a current operator priority with Barriers, Placement & Verification accounting for a third of reported technologies closely followed by Intervention Equipment which accounts for nearly a quarter of reported technologies.

Technology spend on P&A is less than 9% of the total technology budgets reported with only four operators investing more than £1MM on progressing P&A technologies. Spend in this area has shown a decline between the 2018 to 2019 submissions.

The lower level of operator engagement and spend on Well P&A technology is in contrast to the ramp up of activity and expenditure forecasted for well decommissioning activities in the UKCS over the next 10 -15 years.


Further Information



Technology maturity (Operators plans)

Operator focus on Existing Technology solutions features far less in this category than any other, accounting for just less than a third of reported technology.  Subsea systems (where existing technology also meets a third of technology needs) is the only other category where existing technology does not account for at least 50% of operator solutions. The proportion of P&A technology provided by solutions at early stages of commercialisation, which may subsequently mature into existing technology, is consistent with that reported in other categories.

The majority of technology solutions that operators report are needed to meet their Well P&A activity have yet to mature beyond development and pilot stages. A much higher proportion of Well P&A technology is still in Early Development than in the other categories.  Only Facilities decommissioning shows a higher proportion of solutions at Late Development/Pilot stage.

well plugging abandonment pie chart 2


Technology delivery (Operators plans)

Operators rely on the supply chain to deliver the bulk of technology solutions for Well P&A activity. However, at 51% of reported solutions sourced directly from the suppliers, this ranks lowest among the eight survey categories.

In contrast, collaboration plays a greater role in technology delivery to operators in this category than any of the others, with supplier partnerships, JIP’s and participation in Net Zero Technology Centre projects accounting for 26% of technology solutions.  More notably, this is the only category other than Seismic and Exploration where JIP’s are reported to play a significant role in technology delivery. Along with a growing number of Net Zero Technology Centre projects mentioned in operators plans this would appear to be consistent with the high number of technologies at Early Development.

well plugging abandonment pie chart 3

Technology Sub-Categories

Well inspection & Cement conditions

Well inspection technologies can greatly help operators plan and prepare for P&A activities by confirming the condition of well completions thus helping to refine workscope requirements or confirming the quality of P&A barrier elements. Operator interest is focussed on multi-casing string and thru-tubing logging tools utilising acoustic, ultrasonic, electromagnetic and high energy (Neutron, x-ray) technology to evaluate behind casing cement location and bond quality potentially saving time and cost by avoiding the recovery of tubing and inner casing strings prior to logging.  Although an area reliant on vendor development initially, operator support through access to wells for field trials is key to maturation of the technology deployment and data interpretation


Number of technologies by operator

well plugging abandonment pie chart 4

Technology maturity​

2 - Existing technology (33%)
2 - Late Development/Pilot (33%)
2 - Undefined (33%)

Application Exemplars​

Existing Technologies:
  • Cement bond quality - Probe Multi-String Isolation Logging (MSIL) tool enables thru tubing/casing (multi-layer) evaluation of cement bond quality for isolation evaluation for barrier assessment and P&A planning without the need to pull tubing. The technology has been successfully trialled in 6 wells in the SNS demonstrating good agreement with conventional cement bond logging. (Chrysaor)
  • Locate Top of Cement (TOC) - Halliburton Innervue Tool utilises hydrodynamic pressure wave transmission to acoustically tag TOC for abandonment barrier assessment/confirmation during P&A planning and operation. Field trials conducted and further work ongoing to understand sensitivity to annulus fluids. (Chrysaor)
Emerging Technologies:
  • Casing and cement inspection - Baker Hughes nXis - is a multi modal logging tool combining high energy and low energy techniques into a single sensing system. Neutron, x(y)-ray, electromagnetic and ultrasonic inspection techniques provide a thru tubing means to assess condition of casing and the quality and quantity of cement in the annulus behind casing. (Net Zero Technology Centre)

Intervention equipment

With focus firmly on securing cost savings, operators are looking at use of alternatives to rigs, a range of deployment solutions and intervention tools to reduce operational time on the well and to ensure the quality of abandonment barriers. Increased use of monohull vessels (LWIV, DSV) and specialist rigs for aspects of subsea P&A scope and use of hydraulic workover and coil for thru-tubing, rigless intervention is reported.  Evolution of P&A specific intervention systems is being supported by operators including enhancing perf-wash-cement systems as alternatives to costly section milling alongside emerging technologies such as casing expansion to enhance/remediate cement barriers.


Number of technologies by operator

well plugging abandonment pie chart 5

Technology maturity​

3 - Existing Technology (25%)
3 - Early Development (25%)
3 - Late Development/Pilot (25%)
3 - Early Commercialisation (25%)

Application Exemplars​

Existing Technologies:
  • Perf-Wash-Cement (PWC) – An alternative solution to section milling saving time (cost) and avoiding issues with milling swarf. The casing is first perforated before jet washing removes cement and debris behind the casing and finally cement is pumped to create the desired isolation barrier.Rig-less sytems are under development. (Shell)
  • Cement plug bond quality – Propagation of high frequency hydraulic pulses cause vibration of free hanging pipe to promote even distribution of cement during plug placement, improving bond quality and reducing channelling and micro-annulus occurrence. (Shell)
Emerging Technologies:
  • Casing expansion tool – Wireline deployed technology that locally deforms casing without loss of mechanical integrity causing it to compress existing annular cement. Dislocation and compression of the cement creates a denser, less permeable barrier to flow or closure of leak paths through existing micro-annuli or cracks. (Shell)

Tubing and casing removal

Tubing casing and removal is done today with conventional reamers and shears, operators use technologies to reduce time, and therefore rig costs.  Other technologies still under development aim at reducing time more dramatically and even remove the need of rigs eventually


Number of technologies by operator

well plugging abandonment pie chart 6

Technology maturity

3 - Early Development (38%)
3 - Undefined (38%)
1 - Early Commercialisation (13%)
1 - Existing Technology (13%)

Application Exemplars​

Existing Technologies:
  • Improved casing milling tools, mechanical based Technologies (Baker Hughes AMT) now exist to make these operations more efficient and reduce rig time (CNR)
  • Control Cutter - Bespoke shearing device for surface multi-string cutting seeks to reduce the time spent on cutting and recovery - reducing rig time (Shell)
Emerging Technologies:
  • Plasma cutting technology is being developed to be deployed down hole in a rig less system to replace costly rig based section milling. (CNR International)
  • Rocket fuel cutting is being developed as an alternative to explosive cutting and can be deployed rig less. (Total)
  • FORO Laser for Downhole cutting of Conductors and Tubulars also can be deployed rig less (Chrysaor)

Barrier material, placement and verification

New barrier materials proposed can be combined with more efficient placement methods removing need for casing section removals and deployment of a rig.   In addition, natural barriers (like shale and salt) are being studied as an efficient and effective barrier technology.   New barriers still need a thorough qualification process combined with advanced verification tools

well plugging abandonment pie chart 7

Technology maturity

4 - Undefined (34%)
3 - Early Development (23%)
3 - Late Development/Pilot (23%)
1 - Early Commercialisation (8%)

Application Exemplars​

Existing Technologies:
  • Agitator - Wireline run tool set in completion string excites tubing while pumping, cement set around un-centralised tubing could develop a leak path along the low side of the hole resulting in ineffective isolation. (Shell)
Emerging Technologies:
  • Alternative barriers to cement are regularly being tested –, low melting point alloys (Bismuth), Resin’s, Thermite plugs, Rheological based solution’s are examples of JIP’s in progress, promising possible rig less abandonments (Spirit/
    Net Zero Technology Centre)
  • Natural barriers - Shale or Scale as a barrier, are being researched as alternative barriers.

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.