Technology Editor, Subsea & Seismic
HOUSTON –How ExxonMobil qualified nickel-based welds for use on deepwater SCRs was the topic under discussion by Geoff Dunn of ExxonMobil Development Co. today at the DOT in Houston.
The work was done to qualify welding procedures based on company welding requirements and to further characterize the fatigue performance of the Inconel material. The SCR Ni-based welding program fabricated Inconel girth welds in two positions to simulate the two positions used in the production of SCR pipes for deepwater installation.
"Results of the full scale fatigue testing showed performance above the 1984 DOE C-Design curve for all tests," said Dunn. "Stress levels of tested samples were selected to allow for the performance curve to be established consistent with design curves."
According to ExxonMobil, the welding using P-GMAW was an alternative, provided quality controls are maintained.