Why Decision-Making Is the Silent Constraint in North Sea Decommissioning

Ask most people where North Sea decommissioning gets stuck and they’ll point to rigs, vessels, or the supply chain. They’re not entirely wrong – but they’re not looking in the right place either. The real constraint is upstream of all of that, buried in the process of reaching decisions in the first place.

Behind every plugged and abandoned well sits a chain of technical and commercial choices, each requiring evaluation, alignment, and sign-off across multiple teams. As activity volumes grow, it’s that decision layer, not the execution layer, that’s increasingly determining the pace of progress.

A Critical Phase for North Sea Decommissioning 

North Sea decommissioning has moved firmly into execution mode, and the numbers are hard to ignore.

With a projected spend north of £20bn over the next decade and hundreds of wells requiring plug and abandonment (P&A) each year, many of them already overdue, the scale of what’s coming is genuinely unprecedented. We have never attempted to decommission at this pace, with this level of regulatory scrutiny, against this kind of cost pressure.

And the pressures aren’t easing:

• Regulatory expectations continue to rise, with greater emphasis on demonstrable compliance

• Costs are escalating, and delays are the single biggest driver of that escalation

• Energy transition timelines are compressing the window for getting this done

• Asset and unit availability is tight, meaning any slippage cascades fast

Despite all of this, progress has lagged expectations. Backlogs are building. Campaigns keep slipping. And the instinctive response has been to look at operational capacity; more rigs, better logistics, faster execution.

That’s the wrong diagnosis.

The Hidden Constraint  

There’s a tendency to treat decommissioning as an engineering and logistics problem. In one sense it is, but that framing misses something fundamental. Decommissioning is, above all else, a decision-intensive process.

Each well presents several technically viable pathways. Selecting one means working through evaluation, stakeholder alignment, and formal approval; typically involving multiple teams, disciplines, and sign-off layers.

A single well decision can pull in:

• Multiple technical options
• Cross-disciplinary input
• Formal approval layers
• Compliance with regulatory frameworks
• Trade-offs across safety, environmental, and cost objectives

Scale that across hundreds of wells, each with its own uncertainties, its own data gaps, its own stakeholder landscape, and the cumulative weight of that decision-making becomes enormous.

The result is a substantial, largely invisible layer of friction sitting between planning and execution.

The Compounding Effect of Change

Decommissioning programmes rarely unfold as planned. New subsurface data emerges. Operational constraints shift. Regulatory guidance gets updated. When any of those things happen mid-programme, teams typically have to:

• Re-evaluate options
• Re-align stakeholders
• Re-run technical and risk assessments
• Re-submit for approval (MOC/AMOC/derogation processes)

On complex wells, this cycle can repeat two, three, or more times. What looks from the outside like an execution delay is often something more fundamental: a team working hard to reach a decision they can actually stand behind.

The Cost of Complexity   

The industry has put real effort into standardising how decommissioning is executed. Processes, procedures, contracting models – much of this has matured considerably. But the decision-making layer that sits upstream of execution? That’s largely been left to chance or as it was done before.

Walk into most operator organisations today and you’ll find:

• Spreadsheets holding the technical modelling together with tape and formulas
• Word documents serving as the primary vehicle for technical justification
• Workflows that vary by team, by asset, and sometimes by individual
• Little to no auditable record of how decisions were actually reached

Every individual decision still has to go through its own cycle:

1. Option generation 

2. Technical validation 
3. Risk assessment 
4. Approval

And in many cases, that cycle runs more than once before anyone picks up a tool.

None of this is designed for scale. As volumes increase and scrutiny intensifies, the inconsistency compounds, and so do the consequences.

A Growing Problem

 What makes this particularly difficult is that the problem is actively getting harder, not easier.

Wells Are Becoming More Complex

The wells that remain tend to be the harder ones. Late-life assets frequently present:

• Degraded, incomplete, or contradictory historical data
• Higher subsurface and mechanical uncertainty going into the programme
• Technical configurations that don’t fit neatly into standard decision frameworks

Scrutiny Is Increasing

At the same time, the NSTA and other regulators are placing growing weight on the quality of ALARP (As Low As Reasonably Practicable) decision-making. Operators need to be able to demonstrate clearly:

• Which options were considered
• Why certain options were rejected
• How final decisions were justified

Delays Are Increasingly Costly

In a market where rig and vessel availability is tight, any hesitation in the decision cycle hits project economics hard:

• Higher operational costs
• Increased non-productive time (NPT)
• Missed campaign windows

Poor decision-making doesn’t just slow things down, it makes projects materially more expensive and leaves operators more exposed than they need to be.

The Risk of Getting It Wrong

The cost of getting this wrong isn’t abstract. Poorly structured decision-making tends to produce:

• Delays in decommissioning campaigns
• Escalating costs and inefficiencies
• Suboptimal technical outcomes
• Weak or missing audit trails that create regulatory exposure

One of the most common gaps we see is the inability to explain, clearly and with evidence, why certain options were ruled out. That might feel like an administrative problem, but in a regulatory review or a legal dispute, it’s far more serious than that.

Every decommissioning decision is, ultimately, a matter of public record. The bar for what’s “good enough” is only going one direction.

What Needs to Change 

The industry has spent years improving how it executes decommissioning. The next frontier is improving how it decides. Operational excellence will always matter, but it won’t on its own close the gap between where the industry is and where it needs to be.

What that means in practice:

• From documents to structured workflows
• From single-option thinking to exhaustive multi-scenario evaluation
• From implicit reasoning to explicit, auditable justification
• From manual review to integrated compliance validation

Decision-making needs to be treated as a discipline in its own right, not an afterthought, and not something that gets sorted out informally.

The Role of Technology

There’s growing recognition across the industry that the tools used to support decommissioning decision-making haven’t kept pace with the demands being placed on them. That’s starting to change.

What the industry actually needs, and what effective decision support looks like at this scale, comes down to a few core things:

• A structured evaluation framework that applies consistent rules regardless of who’s doing the assessment or which asset it relates to
• The ability to generate and compare multiple technical options systematically, rather than anchoring on the first viable path identified
• An embedded record of how every decision was reached, not reconstructed after the fact, but captured as part of the process itself

Put differently, the capabilities that matter are:

• Speed in generating technically viable options without sacrificing rigour
• A clear separation between what’s technically feasible and what’s regulatory compliant – assessed independently, not conflated
• Decision rationale that’s transparent, traceable, and meaningful to regulators – not just internally coherent
• Workflows that work the same way across assets, teams, and campaigns so quality doesn’t depend on who happens to be leading the work

Introducing DecomX

DecomX was built to address exactly these gaps. The starting point was straightforward: if decision-making is the silent constraint, then the tools teams use to make decisions need to be purpose-built for the job and not adapted from general-purpose software that was never designed with decommissioning in mind.

In practice, that means helping teams work through the decision process more systematically; covering more options, building in compliance checks, cutting down the back-and-forth, and producing a record that holds up to scrutiny. Not by replacing engineering judgement, but by giving it better structure to work within.

• Work through multiple technical scenarios quickly, without missing data in the analysis
• Have compliance considerations embedded in the process rather than bolted on at the end
• Spend less time revisiting decisions that should have been settled earlier
• Leave behind a clear, auditable account of how each decision was reached and why

A New Definition of Success

The organisations that lead the next phase of North Sea decommissioning won’t necessarily be the ones with the most assets or the biggest execution capacity. They’ll be the ones that have figured out how to make good decisions consistently, at volume, under pressure, and in a way that stands up to scrutiny after the fact.

That’s not an aspirational statement. It’s a practical reality that’s already playing out in project delays, cost overruns, and audit findings across the basin. The question for most operators isn’t whether to improve how decisions are made – it’s whether they can afford to wait much longer before doing so.