In response to demand from customer BG Group to replace defective caissons more quickly, WorleyParsons introduced an industry first by developing a new technique for removing caissons, the pillars which underpin many North Sea platforms, a new method which not only allowed the job to be done in a third of the time but was also safer.
In April 2014, subsea defects on the Lomond platform’s C6 caisson were identified along with badly corroded internal dip pipes. Given that the caisson was located directly above a gas export line which it had the potential to damage if dropped, the risk of some part detaching during the removal process had to be mitigated.
WorleyParsons pumped expanding foam down the caisson, fully encapsulating corroded internal dip pipes. This removed the risk of them detaching during removal and falling onto a gas export line located below and allowed the top of the caisson to be cut away in larger sections than before, saving time and reducing cost.
This innovation improved efficiency by enabling the caisson to be removed in eight weeks, where more traditional methods would have taken 22. The process demonstrates the power of collaboration and holds promise for the future, as BG Group plans to use this technology for the removal of similar caissons on other North Sea assets.
Finding new, innovative ways of working is can help secure the future of our industry and will help to make the industry. BG Group’s Vice President, UK Operated Assets, Steve Cox, commented:
“As an industry, we need to work together to develop innovative methods and technologies. This solution has been an outstanding achievement and is testament to great team work and commitment from all companies involved and has the potential to be used for any other similar caissons in poor condition.”
View a video describing the project here.