top of page

I Decommissioning

I Independent, engineering‑led decommissioning expertise for complex offshore assets

​

Crondall Energy provides independent, engineering‑led support for the decommissioning of offshore oil and gas facilities, subsea systems and associated infrastructure. Drawing on over two decades of offshore engineering experience across floating facilities, subsea pipelines, wells and marine operations, we support clients in developing robust, proportionate and regulator‑ready decommissioning strategies. 

​

Our approach is grounded in a thorough understanding of original design intent, operational history and through‑life asset integrity. This enables informed decision‑making that balances technical assurance, cost control, regulatory compliance and risk reduction throughout the decommissioning lifecycle.

​

Decommissioning - Pipelines.jpg
Decommissioning - Shell Curlew.jpg
Decommissioning - Platform.jpg

I Integrated decommissioning support from planning to execution readiness

Crondall Energy supports decommissioning projects from early strategy development through to execution readiness, integrating technical, commercial and regulatory considerations.

 

Our services include:

  • Decommissioning strategy development and options screening across technical, commercial, safety and environmental aspects.

  • Comparative Assessment (CA) support to inform decommissioning decisions

  • Preparation and technical input to Decommissioning Programmes (DP)

  • Concept select and Pre‑FEED decommissioning studies

  • DECOMMEX estimates and cost benchmarking

  • Subsea, pipeline and structural integrity assessments to support end‑of‑life decisions

  • Assessment of reuse, repurposing and late‑life asset optimisation opportunities

  • Options for support in dismantling options of floating facilities

 

Our multidisciplinary teams bring experience across floating and fixed facilities, subsea systems, pipelines, wells and marine systems, allowing us to take a holistic and practical approach to decommissioning challenges.

​

I Floating facilities decommissioning and disconnection expertise

Crondall Energy has specific experience supporting decommissioning strategies for floating facilities, including FPSOs, FSOs and other floating production assets.

 

This includes technical input to planning for:

  • Facilities shutdown, flushing and disconnection scope

  • Marine, mooring and riser disconnection strategies

  • Disconnect and tow‑away assessments for floating units

  • Interface management between topsides, hull, marine and subsea scope

  • Identification and management of decommissioning risks during transition from operations to removal

 

Our understanding of floating asset design, marine systems and operational interfaces allows us to support technically credible and safe floating facilities decommissioning solutions.

​

I Subsea and pipeline decommissioning support

Crondall Energy provides engineering support to subsea and pipeline decommissioning activities, including technical assessment of end‑of‑life condition, integrity and recoverability.

 

This includes:

  • Technical input to subsea and pipeline decommissioning Comparative Assessments

  • Assessment of flushing, isolation and disconnection requirements

  • Integrity assessment to support removal, partial removal or leave‑in‑situ decisions

  • Independent engineering review to support contractor selection and execution planning

 

Our pipeline and subsea expertise enables us to provide objective and objective technical advice technical advice, while recognising the evolving regulatory and environmental expectations associated with offshore decommissioning.

​​

I Independent technical evaluation and assurance

Crondall Energy routinely provides independent technical assurance services to support decommissioning procurement and execution. This includes subsea decommissioning tender technical evaluation services, where we act independently of any installation or removal contractor.

​

Recent work includes providing independent technical evaluation support for subsea decommissioning tenders, enabling clients to assess contractor proposals on a consistent, transparent and technically robust basis.

​

I Managing NORM considerations

Decommissioning activities can involve exposure to Naturally Occurring Radioactive Material (NORM), particularly during flushing, isolation, disconnection and removal of hydrocarbon systems.

​

Crondall Energy supports clients by ensuring NORM considerations are appropriately identified and addressed within decommissioning planning, including:

​

  • Identification of credible NORM risks associated with late‑life and decommissioning activities

  • Integration of NORM considerations into flushing, disconnection and removal strategies

  • Technical input to risk management measures and regulatory engagement

 

This ensures NORM is managed safely, proportionately and in accordance with regulatory requirements.

​

I Supporting energy transition and reuse opportunities

Where appropriate, Crondall Energy supports decommissioning strategies that consider reuse, repurposing or integration with emerging energy transition developments. This includes evaluating technical feasibility, structural suitability and lifecycle implications as part of broader asset transition planning.

​

By combining decommissioning experience with expertise in CCUS, electrification and offshore renewables, we help clients align late‑life decisions with long‑term energy strategy and regulatory expectations.

Updated: May 2026

bottom of page