Case Study

Caisson Restraint and Replacement

North Sea platf
This scope encompassed NDT inspection, assessment, repair engineering, and restraint rigging installation on a damaged produced water caisson located on a North Sea fixed platform. It also involved the preparation, removal, and replacement of the damaged caisson.
AquaTerra conducts dropped objects surveys for offshore assets
The Challenge

The site presented a hazardous work environment, so safety considerations were paramount. The existing inspection contractor faced limitations as they lacked the capability for breathing apparatus (BA)-assisted inspections, prompting the need for a fresh approach.

Due to the damage's potential impact on the platform's integrity, a fast response was required. The damaged section also posed immediate risks of object dropping and required careful handling.

The task required a mix of skills due to the multifaceted nature of underdeck work. This called for a team with varied expertise to tackle the challenges effectively. Faced with a shortening weather-window, the execution process had to be carefully planned. The work was intricate, involving tasks such as hydraulic flange torquing and precise component removal/replacement.

Key Summary
  • NDT inspection, repair, and restraint rigging for a damaged produced water caisson on a North Sea platform.
  • Hazardous environment, BA-assisted inspections, tight timeline, dropped object risk, weather sensitivity, and complex execution.
  • Solution included skilled rope access teams, pre-engineering, turnkey management, and construction-led engineering.
  • Result encompassed efficient shutdown, expert rope access, QuikDeck implementation, precise caisson handling, and comprehensive execution.
  • Added value: Critical execution under BA, safety, efficiency, simplified management, and innovative QuikDeck approach.

Role, Co.

The Solution

AquaTerra Group mobilised proficient rope access teams skilled in BA-assisted inspection and installation. In the meantime, pre-engineering and careful planning of construction tasks was well underway. This strategy aimed to minimise time needed for installations while ensuring precision and efficiency.

The project management of this scope took a comprehensive turnkey approach, overseeing the project from start to finish, encompassing inspection, engineering, and site remediation, providing a streamlined process.

To ensure seamless execution, engineering principles were firmly integrated into the construction process, facilitating the successful implementation of the restraint solution.

The Result

AquaTerra executed the necessary pre-shutdown tasks proficiently, using line-fed BA technology. . Rope access teams already expert in working with breathing apparatus were deployed for these installations, ensuring smooth progress. This was significant in reducing the downtime necessary for the project as a whole.

Introduction of innovative QuikDeck technology across all work sites gave teams quick, safe access and enhanced the efficient delivery of the project. The precise removal and installation of caissons were managed using existing runway beams.

AquaTerra Group successfully managed the entire scope of the project, providing the necessary equipment and resources to ensure a comprehensive execution.

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