Welding system proves worth underwater

CAPE Group has developed a semi-automatic, remotely controlled orbital welding system to repair oil and gas pipelines on the seabed.

Offshore staff

SINGAPORE -- CAPE Group has developed a semi-automatic, remotely controlled orbital welding system to repair oil and gas pipelines on the seabed.

During a trial in Abu Dhabi, two sections of 30-in. (76-cm) diameter pipe were welded subsea in a hyperbaric chamber designed to house the welding equipment. According to CAPE, X-ray analysis and mechanical testing of the weld showed good results.

The company now plans to test the system on a 48-in. (122-cm) pipeline in order to pre-qualify the technique for pipeline repairs for two Qatari operators. Managing director Simon Hartog said others had attempted to introduce underwater orbital welding systems previously, but CAPE believes this is the world’s first commercial unit.

Despite recent advances in mechanical pipeline repair systems, the company maintains that welding is still vital to restore a damaged pipeline to its as-designed state, or to repair internally-clad, sour-service lines. But to achieve acceptable results with welding, the damaged pipeline normally has to be lifted out of the sea.

12/03/2009

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