Efficient and cost-effective pipeline decommissioning in the Gulf of Thailand

The decommissioning of subsea infrastructure is an evolving challenge for the oil and gas industry. In the Gulf of Thailand, Centurion Group and Centurion APAC (Centurion) are playing a key role in supporting the removal of 250km of pipeline - much of it encased in concrete weight coating (CWC) - using reverse pipelay techniques. Starting in March 2024, we have been providing essential cutting solutions, including shears, chopsaws, and pipe recovery tools, enabling efficient, cost effective and safe pipeline recovery operations.

With an unprecedented scale of decommissioning activities underway around the world, this project offers valuable insights for vessel operators and contractors.

The client

The client, a leading subsea services provider, is responsible for the safe, efficient and cost-effective removal of aging subsea infrastructure. Their decommissioning efforts involve complex challenges, including the recovery of 250km of subsea flowline networks while adhering to strict environmental and regulatory requirements.

Client requirements and challenges

The project involved recovering 64 pipelines, ranging from 2 km to 21 km in length and 6” to 18” in diameter —many of which were encased in concrete weight coating (CWC).

Key challenges identified included:

Ensuring efficient and cost-effective pipeline recovery

Managing variable pipeline conditions and information gaps with legacy assets

Meeting environmental regulations and managing pollution risks

Adapting to external weather conditions that could potentially affect project timelines

Selecting the right cutting tools to optimize performance and reduce downtime

Our solution

Centurion worked closely with project stakeholders to help determine the most efficient removal methods, balancing environmental regulations, operational constraints, and safety. The project utilised multiple methodologies, including:

S-Lay technique

Cut and recover approach using shears and chopsaws

Ongoing collaboration between the operator, EPRD contractor, and service providers, along with real-time project learnings has been key in refining methodology, equipment selection, and execution. This includes:

Tailored cutting tool selection based on pipeline specifications

Continuous refinement of cutting methodologies

System Integration Testing (SIT) to validate equipment performance

The results

Centurion’s contributions have significantly improved the efficiency of the decommissioning project, achieving to date (as of March 2025), the following:

56 pipelines removed in 12 months, with 8 remaining

Over 22,000 shear cuts and 5,000 chopsaw cuts completed

Optimized blade selection for different pipeline conditions:

Tungsten Carbide Tipped (TCT) Blades: Fastest cuts recorded – 2” pipe in 1 minute, 16” pipe in 4 minutes

Diamond Blades for CWC: Cutting times – 16” CWC pipe in 12 minutes, 18” CWC pipe in 18 minutes

Enhanced shear performance with Genesis GSS775 shears for precise and efficient cutting

Reduction in equipment downtime

Conclusion

Centurion Group and Centurion APAC’s expertise in cutting and recovery solutions has played a key supporting role in the success of this large-scale decommissioning project. By employing a collaborative approach, innovative methodologies, and adaptive execution strategies, we are contributing to an efficient, cost effective and safe pipeline removal process.

With the demand for pipeline decommissioning surging worldwide and set to grow even further, these insights will be invaluable in helping clients optimise future projects.

Contact information

For more information contact the team in Perth, Western Australia at CSSAU@centurionaprs.com or in Singapore: +65 6863 4470 or CSSSG@centurionaprs.com

Find out more about our subsea services and lifting services.

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