DEEPWATER WELDING AND INTERVENTION TECHNOLOGY

Within the next few years, the offshore industry will be seeking to exploit hydrocarbon reserves at depths inaccessible to saturation divers, and at which the welding processes currently in offshore use will not operate. Alternative processes exist for the water depth range 500 to 100 metres, and these have been shown to be viable in laboratory trials. Further work is required to bring them to full operational status, and to integrate them with the wide range of other equipment required to carry out a complete underwater fabrication procedure without diver intervention. Although alternative fabrication techniques exist, it is generally agreed that if hyperbaric welding can be shown to be reliable, and to produce acceptable joints, it will continue to be used by the offshore industry. A 250 bar research facility is being commissioned which can be used for undertaking studies into the performance and properties of arc welding at pressure equivalent to a water depth of 2.5km.