Aberdeenshire headquartered, multi-discipline construction and maintenance specialist, AquaTerra Group, has successfully completed a landmark internal repair of a seawater and drilling cuttings disposal caisson on a major North Sea operator platform , using its innovative C-Cure lining solution.

The project marks the first time a full-length internal caisson repair has been executed on an offshore production facility bringing a defective caisson back into service. In total, AquaTerra lined 30 metres of a 30-inch caisson, targeting areas of internal wall thinning while providing a continuous maintenance barrier across the entire length of the structure. The offshore campaign was completed in approximately one week, including set-up, execution, post-inspection and equipment removal.

Until now, such repairs were widely regarded as uneconomical due to the high cost and extended execution time associated with the only other feasible option, a  full replacement.

C-Cure was installed and cured within a single 12-hour shift, with post-inspection confirming 100% adhesion and a perfect fit over the full length of the caisson. The solution enabled rapid restoration of integrity at a fraction of the time and cost of replacement, reducing repair expenditure to less than 20% of the alternative and eliminating several months of expected downtime.

Stephen Taylor, Managing Director AquaTerra Group, said: 
“This project demonstrates what’s possible when practical engineering innovation meets real offshore need. The integrity market has become increasingly value-driven, and solutions must now deliver measurable outcomes without compromising safety or asset life. C-Cure has enabled the efficient restoration of critical infrastructure that would previously have been written off as too costly or time-consuming to repair.”

The repaired caisson will be brought back into service during the 2026 shutdown, enabling use of this vital infrastructure for the first time in several years. The repair is expected to ensure safe, maintenance-free operation for the remainder of the asset’s operational life, while protecting against further internal erosion and corrosion.

The caisson repair was delivered for the asset’s engineering and project management contractor, with a major North Sea operator as asset owner. Liner specification, design and supply were completed by AquaTerra, alongside all offshore construction, rigging, liner installation and inspection works.

KeyFacts Energy Industry Directory: Aquaterra Energy