Very heavy wall X-70 DSAW pipe for tension leg applications

Assembled in strings, Tendon Pipes connect the Tension Leg Platform (TLPs) and it’s topsides with the sea floor. So far, a water depth of 5,000 feet has been considered the limit for TLPs. New TLP concepts are passing this limit approaching 10,000 feet. The new larger oil and gas fields, specially in the Gulf of Mexico (GoM), are expected in water depths of 7,000 feet and more. Pipes in the 40 mm plus (1.6”) wall thickness range are requested for these water depths. These pipes have to fulfill extremely tight tolerances and toughness requirements. This article discusses the manufacturing of these pipes with the Submerged Arc Welded (SAW) UOE process. Experience and data out of order executions and trials are presented. (AU)