Vessel-based cut and recovery of 120+ subsea wellheads South East Asia

PROJECT OVERVIEW

A major operator was seeking a strategic partner to perform cutting and recovery of over 120 subsea wellheads in water depths of 70-100m in the Gulf of Thailand using a vessel-based approach. This would be Claxton’s largest volume for a multi-string cutting and recovery operation from a vessel to date.

THE CHALLENGE

The project scope required Claxton, a brand in Acteon’s Energy Services division, to design, test and fabricate bespoke equipment.

Due to the variety of operating environments, a flexible approach was required to find adaptable solutions. Multiple varieties of tooling and bespoke equipment would need to be quickly developed and supplied within an eight-week lead time to get the spread and personnel mobilised from the UK and Singapore to Thailand whilst mitigating the challenges of COVID-19 travel restrictions which were in place at the time.

CUSTOMER GOAL

The goal was to safely cut and recover over 120 wellheads within the project schedule. The customer needed a proven and consistently reliable cutting method to sever all strings in one go ranging from 7” inner casing up to 30” to optimise vessel utilisation and improve project efficiencies. Claxton’s cut and recovery methodology, which utilises its marine growth removal tool (MWRT), has a proven track record of reducing the recovery time.

OUR SOLUTION AND ITS COMMERCIAL BENEFITS

Market-leading services and integrated solutions

• We used our in-house short swallow multi-well retrieval tool to accommodate the short swallow subsea well HP housing on the project.
• Design of multi-well retrieval tool dog clamps were required so we were not limited to the 16-3/4” Cam hub dogs and 16-3/4” H4 Dogs.
• We used our in-house capability to rapidly design bespoke drift cleaning tools for 7”, 9-5/8”,13-3/8”, 20” & 30” sizes.

We work at scale with a proven track record for delivery

• Claxton has a proven track record of operating in South East Asia with the ability to cut a variety of subsea wells in challenging conditions.

We optimise the project to increase commercial value

• Our proprietary multi-string cutting (MSC) tool is a proven and consistently reliable cutting method that can sever all strings in one go; ranging from 7” inner casing up to 30” which minimised vessel time, therefore, contributing to overall increased commercial value of the project.
• Our ability to perform recovery after cutting, utilising our multi-well retrieval tool resulted in reduced recovery time and proved to be a reliable and safe method.

We minimise the environmental impact

• We cut below the mudline which left a clean seabed.
• We reduced the carbon footprint of the vessel required to remove wells by providing a timesaving cutting and immediate recovery solution.

PRODUCTS USED

• Multi-string cutting (MSC) tool 2.0 with ancillary equipment
• Multi-wellhead retrieval tool with ancillary equipment
• Marine growth removal tool
• Drift cleaning tool with ancillary equipment
• Deployment frame on the vessel
• Wellhead flow port plugging package

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