History: Statoil ASA had earlier launched a development program to establish technology and a tooling system for diverless tie in and welding of subsea pipelines; the Remote Pipeline Repair System, RPRS.
The RPRS system consists of three main assemblies;
– RWH which acts as the foundation of the system
– The Remote Welding POCO (RWP) which is the carrier of the Remote Welding Tool, the control system for power distribution, welding- and preheat equipment together with support tools and equipment
– The Remote Welding Tool (RWT) – the assembly actually making the weld
Challenge: Imenco was awarded both the concept engineering contract and the detail engineering contract for the RWH. During the course of the contract Imenco delivered around 1300 documents including design reports, assembly and part drawings & detailed fabrication specifications.
Response: Imenco’s response was to design a robust, simple but innovative Habitat.
Overview: The Habitat consists mainly of a base structure, with leg and mud mat assemblies, pipe-claw assemblies and pipe door assemblies. The base structure is designed to be very rigid in order to provide a stable structure during subsea operation. It is also designed for easy and comfortable working conditions offshore.
The leg and mud mat assembly facilitates the different seabed conditions – topography etc. The habitat can tilt, accommodate large height adjustments and axial position stroking provides the ability to adapt to different seabed conditions. The pipe claw assemblies act as cradles for the pipes. The pipes are free to pivot in the claws for alignment prior to welding. The pipe door provides a seal around the pipe to ensure a dry welding atmosphere inside the habitat. The assembly provides a constant tension on the rubber door gasket and facilitates automatic closing and opening of the doors.
Conclusion: The project was tailor made to suite Imenco’s primary and core modus operandi, which is to provide a Smart Solution for a client’s needs. The project was challenging throughout, forging new technological concepts, contributing to new and valuable knowledge for Imenco’s E & D team.