Precision Multi-String Severance in the Gulf of Thailand
Challenge
Our customer required the severance of 12 cemented, 4-string casings with centralisers in the Gulf of Thailand. This project had the added complication of a significant amount of dredge material and debris surrounding the wellheads, which restricted access for cutting operations. Meeting strict time and budget targets demanded reliable cutting technology, seamless coordination of equipment across multiple regions and continuous offshore operations.
Solution
Our team conducted dredging and debris removal at all cut locations, removing approximately 3,804m³ of sediment using a Hydraulic Dredge and Orange Peel Grab, to ensure clear access for cutting.
The project involved casing strings, in sizes ranging from 30” to 9-5/8”, each with various wall thicknesses, highlighting the importance of choosing the right cutting solution with the versatility and precision to complete the project.
Each location was successfully severed using our Diamond Wire Saw, achieving consistent cut times of under one hour. Operations ran continuously, with all tooling managed and operated remotely, topside, for enhanced safety and control.
A Diamond Wire Saw was selected as the optimal cutting method because it offered:
- Precision: Cutting complex subsea structures cleanly and accurately to the required depth, minimising the risk of miscuts.
- Structural integrity: Performing effectively on vertical structures without being affected by compression forces.
- Safety: Allowing topside operation, keeping personnel away from hazardous subsea conditions.
- Efficiency: Delivering consistent cuts in under one hour, keeping the campaign on schedule.
- Reliability: Our patented Diamond Wire Saw design minimises the risk of wire snap or equipment failure, critical for a multi-location campaign.
Results and impact
The 60-day offshore campaign was completed ahead of schedule and within budget, with no wire snaps or miscuts across all 12 cutting locations – a 100% success rate.
This project reinforces Ashtead Technology’s reputation as underwater cutting specialists, delivering complex subsea decommissioning scopes with precision, efficiency and safety. By combining innovative tooling technology, experienced personnel and global logistics expertise, Ashtead Technology provided a seamless end-to-end service that enabled our customer to achieve their decommissioning objectives with confidence.
To learn more contact our Mechanical Solutions team.