Case Study: Caisson Replacement
Nortech are delivering a wide range of Caisson Replacements from studies to complete projects across a number of North Sea offshore facilities via a multi discipline engineering team. In this instance, after successfully completing a FEED study, Nortech were awarded the Detail Design phase to replace the existing Produced water Caisson.
The recommendation of the FEED study was to replace the Caisson using a topsides, ‘cold work’ solution.
In order to ensure full operability during the construction phase, a ‘three stage project’ approach was adopted
The stages are as follows:
· Provision of temporary produced water overboard dump line.
· Working from a semi-permanent platform at EL. +10.5 - Removal of existing Caisson.
· Working from a semi-permanent platform at EL. +10.5 - Installation of new Caisson.
The design of the temporary overboard dump line ensured that the operability and compliance of the existing Produced Water system was maintained. A temporary working platform and runway beam was designed at the spider deck level to facilitate destruct and construct activities.
In the Caisson installation, to eliminate time consuming ’hot work’ the Project team adopted a ‘cold work’ industry proven mechanical connector solution.