Thought Leadership

By Paul Brindley, Subject Matter Expert - Asset Management, Major & Decommissioning Projects at KBR

Decommissioning is an inevitable stage in the life of any energy asset. When production ends, infrastructure doesn’t simply disappear. Wells, structures, pipelines and seabed features remain long after operations stop. Too often, however, decommissioning is treated as an afterthought. Looking at it instead as a waste management challenge provides a clearer way to manage what follows once production ends.

From late-life operations to shutdown

Much of the work involved in decommissioning is well understood. Systems must be isolated, equipment made safe and structures prepared for removal. The uncertainties come from when this work will be carried out and the condition assets are in by that point. In offshore oil and gas, the drive to maintain production right until the end often overlooks the work needed to properly isolate wells and infrastructure, which can take years after production stops.

Until reservoirs and pipelines are fully isolated, platforms stay live and maintenance requirements remain largely the same. Operating costs only reduce marginally until this point is reached, particularly where plugging and abandonment of non-producing wells has been delayed. The Brent field is one example, where preparatory work began in 2006 and decommissioning continued for nearly two decades.

Leaving this work too late increases cost and complexity. Long periods of suspension extend schedules, attract regulatory attention and expose programmes to supply-chain constraints. Planning for decommissioning while assets are still operating, and while teams, records and systems are intact, allows work to be sequenced more effectively and reduces uncertainty later.

The material left behind

When offshore fields reach the end of production, the tonnes of materials in the jackets, topsides and foundations, accounting for large volumes of steel and concrete need managing. Much of the ferrous and non-ferrous metal can be recycled through established onshore scrap markets, and the North Sea has developed strong dismantling capability to support this activity.

Headline recycling figures only tell part of the story. While ferrous/non-ferrous metals dominate overall tonnage, smaller waste streams often require more planning effort, specialist handling and regulatory engagement. Disposal also depends on the availability and capacity of licensed onshore dismantling facilities, which can become overwhelmed if waste streams/volumes are not identified early.

Similar challenges in newer energy systems

These issues are not unique to the oil industry. As renewable energy assets mature, their own end-of-life challenges are becoming clearer. Offshore wind is a good example. Steel towers are generally recyclable, but composite turbine blades are much harder to process, with recovery options still developing. Many blades continue to go to landfill or incineration.

Many offshore wind projects were designed around a single lifecycle of around 25 years. As larger turbines are deployed, original foundations are often too small to reuse, raising concerns about the long-term impact on the seabed. This remains an active area of discussion within the OSPAR Commission, which works to protect the marine environment.

Onshore battery storage and solar installations add further material considerations. Batteries contain lithium, nickel and other metals that are difficult to recover economically today, while early solar farm modules are already reaching the end of their service lives.

Regulation and liability shaping decisions

Beyond technical challenges, decommissioning takes place within an increasingly demanding regulatory framework. In the UK, decommissioning programmes must be submitted and approved before work can begin.

Responsibility does not necessarily end when ownership changes. Operators and licensees may remain liable for assets up to, and in some cases beyond, the return of a lease. Where assets have changed hands, legislation allows former owners to be called on if current operators cannot meet their commitments. This will increasingly influence late-life transactions and requires careful liability planning.

Challenging short-term thinking

Financial and corporate structures also affect how operators approach decommissioning. In some tax regimes, operators pay tax on production revenues and only recover decommissioning costs after work has been completed. This creates little incentive to set aside funds during productive life and can result in significant cashflow pressure at the end of operations.

Deferring decommissioning is often seen as the easiest response, but experience shows this is a false economy. In the UK, long-term suspended wells, where plugging and abandonment has been delayed, are attracting increasing regulatory attention. In the Gulf of Mexico, hurricane-damaged ‘downer’ platforms led regulators to impose time limits on how long redundant infrastructure can remain offshore.

Ownership changes can increase these risks. Big players often sell assets as production declines, transferring end-of-life responsibility to smaller operators. Tightening regulation means defaults by buyers can leave sellers exposed or co-venturers carrying liabilities. In some tax regimes, insolvency has resulted in orphan facilities, with governments expected to fund clean-up.

What good looks like in practice

Despite these challenges, there are examples of good decommissioning practice. In the Gulf of Mexico, redundant platforms are not allowed to sit offshore for decades. Wells must be plugged, structures removed and sites cleared within defined timeframes, creating a supply chain built around regular P&A and removal activity.

In the North Sea, operators have increasingly moved towards front-end loading by carrying out early surveys of wells, topsides and subsea infrastructure ahead of cessation of production. This planning is essential where activities are constrained by weather windows, lift-vessel availability and limited onshore dismantling capacity.

Supporting late-life and retirement planning

Late-life and decommissioning challenges are best addressed before production stops. This includes understanding when assets are reaching obsolescence, how long critical systems need to remain available and what preparatory work is required to move from operations into decommissioning in a controlled way.

KBR supports operators with life-extension and obsolescence assessments, late-life operations planning and safety-case management, and evaluation of options for suspension, removal or reuse. This includes helping establish structured late-life strategies, clarify regulatory expectations, build appropriate maintenance plans and improve lifecycle documentation.

Planning for what remains

Approaching decommissioning as a waste management problem helps operators understand what remains when production stops and how best to deal with it. Early preparation and realistic planning are central to delivering safe and efficient decommissioning.

About the author:

Paul Brindley is an internationally experienced and accomplished subject matter expert in late life asset management and decommissioning, advising both governments as well as c-suite executives. He has a 40+ year track record of working on some of the world’s most complex offshore oil & gas, nuclear power, and onshore petrochemical design, build, and modification projects. He has over 30 years’ experience in decommissioning assets, having worked on numerous large-scale projects in the offshore sector.