The challenge in the Offshore market
Three typical developments are recognized in the European Offshore Industry: Deep water development, Marginal Field development and Revamping of Offshore Installations. All three developments should meet objective no. 1: reduction of OpEx and CapEx.
Revamping of Installations
Due to the need of longer lifetime expectation on large Oil & Gas fields there is a current need of revamping these installations. Non economical fields with existing plants will be used for new applications like Offshore Wind Turbines.
Benefits of UIT
Improving fatigue strength and improving wear resistance are of high importance to maintain the integrity of (existing) offshore installations. As a result repair and strengthening of welded details with UIT are required to extend the life time and safety. Other benefits are lowering residual stresses, reducing the risk for cold cracking, reducing the potential for stress corrosion cracking and increase the resistance to brittle fracture.
Another benefit of UIT is to optimize on weight. Due to the fact that a double stress is allowed weld details can be smaller (higher FAT class). A second way to reduce weight is by applying UIT in combination with High Strength Steel. 
The UIT treatment can also be applied under water.
Typical application (but not limited to)
“During their lifetime, FPSO systems are subjected to sea wave-induced random loads, which may lead to fatigue failure. Fatigue damage assessment of topside facilities is an important issue, since their repair or replacement will entail shutdown of the production” (Spanos et al, 2003).
  1. FPSO: Piping on Topsides, Topsides, Pedestals and flair booms, Subsea Installations, Ship Hull, Risers and Turret Mooring System.
  2. Semisubmersible: critical welds in steel structure (bracings, columns, trumpets, joints), Pedestals and Turntable.
  3. Jack Up: Jack Up Installations, Pedestals and Turntables.
  4. Platform: Piping on Topsides, Topsides, Pedestals, Bridges, Jackets and Flair Booms
  5. Auxiliary: improvement of the welding process in Pipelaying Vessels, Stingers and Risers.

Almost all stiffeners, brackets and other attachments in ship hulls are joined by non-penetration fillet welds for fabrication reasons. However, the ends of these attachments show frequently high stress concentration due to their geometrical shape and loading. Fatigue cracks may initiate here not only from the weld toe, but also from the non-welded root gap” (Wolfgang Fricke, 2002)