Deep Water Remote Pipeline Repair Using Welded Sleeve Technique Available to Purchase

A technique for sub-sea pipeline repair using remote welding without the use of diverse has been developed. The technique involves the installation of an oversized pipe segment (sleeve) over the join by threading the pipe ends through the sleeve and performing a sub-sea fillet weld between the pipe and sleeve on each end. Current traditional welding techniques use pipe end butt to butt welding performed with the aid of divers in a habitat and are therefore depth limited. This technique is fully remote controlled and has been proven by simulating conditions in a hyperbaric chamber to work down to at least 2500 msw represented by 250 bar. This paper describes the technique, the structural considerations, and the equipment currently being built to perform this task, which will be in test in the second half of 2004 with sub-sea trials to follow. This paper compliments the paper IPC04-0630 “Diverless underwater GMA welding for pipeline repair using a fillet welded sleeve” [2], in which the welding procedural development is described. When compared with traditional welding or mechanical options (in particular for large pipes), the technique provides a much cheaper repair option.