Fuglesangs AS and OceanTech Innovation AS have entered into a partnership agreement in which the two companies offer to perform subsea repairs on steel structures such as caissons, conductor-pipes and riser-pipes, etc., using a robotised installation method. Fuglesangs, the system supplier, successfully completed a repair job of 3 caissons in the Splash Zone at Equinor’s Oseberg field in 2018. Unfortunately, the use of divers resulted in unnecessarily high costs for the project. Divers require calm seas in order to work, and calm seas is a rare thing in the North Sea. Jan Olav Berge of Equinor confirms that a robotisation of the already proven repair technology is very interesting and adds to the toolbox a method that can be both cost-effective and flexible.
Many of the older offshore installations have major issues related to corrosion and structural damage, especially in the Splash Zone (+5 to -10 metres). There are cases where caissons have broken off and fallen to the seabed, which can damage other subsea installations, interrupting production. Most oil-companies have chosen to replace the entire damaged structure (which is very costly) or to repair it using different kinds of clamping solutions. 3X Engineering in Monaco, who is a supplier to Fuglesangs, has developed a wrapping solution especially for the colder North-Sea waters. With a lifetime of up to 20 years, incredible adhesion and the ability to rebuild structural strength, this is a unique technology that can now be installed without divers.
OceanTech has since 2007 developed robotised access tools for operations in the Splash Zone on offshore installations. This work was started under Linjebygg Offshore, where the Splash-Zone division was bought by OceanTech in 2017. By utilising robust and flexible access tools, OceanTech has successfully completed mechanical work, inspections and maintenance that require a high degree of precision.
The partners will be able to do Subsea repairs in both the Splash Zone and in deeper areas, without using divers or support vessels. All stages of the wrapping process, including the removal of marine growth, inspection, grit blasting/UHP-waterjetting, priming and wrapping will be done using manipulator arms and a wrapping machine that are especially developed for the task. The operations are monitored and executed from a topside control unit. This will not only reduce costs significantly, but also the time needed to complete the job will be reduced with up to 50%. Because Fuglesangs and OceanTech has all the equipment and personnel needed, it will also be possible to mobilise on short notice.