This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper OTC 19249, "Influence of Fatigue Issues on the Design of SCRs for Deepwater Offshore Brazil," by A.L.F.L. Torres, M.M. Mourelle, S.F. Senra, E.C. Gonzalez, and J.M.T. da Gama Lima, Petrobras S.A., originally prepared for the 2008 Offshore Technology Conference, Houston, 5-8 May. The paper has not been peer reviewed. Petrobras has been investigating the steel-catenary-riser (SCR) alternative since the beginning of the 1990s. Since then, fatigue verification has been an important issue, demanding good representation of the loading conditions that occur during the lifetime of the riser. The concern with fatigue has motivated Petrobras to research several areas, such as metocean data acquisition, hull design for motion optimization, special touch-down-point (TDP) joints, accurate models for vortex-induced-vibration (VIV) analysis, and the corrosion-fatigue effect. Introduction Installation of the P-18 SCR was a pioneer project of a free-hanging SCR connected to a semisubmersible, and it proved the technical feasibility of the concept. Although this riser was installed as a prototype, it is still working in the gas transfer from platform P-18 to platform P-26. It has been monitored since 1999, and the results are being compared with the design data and with simulations performed with in-house computer programs and other commercial packages that include the complete design methodology. Other SCRs were studied, such as the 12-in. oil-export riser for the P-19 semisubmersible in 770 m of water and the 10-in. oil- and gas-export lines for the P-36 semisubmersible at a water depth of 1360 m. The free-hanging SCR configuration is considered as an available technology for semisubmersible applications, and there is interest in the application of SCRs connected to floating production, storage, and offloading units (FPSOs) because of the trend to use these units for exploration and production in deep water. This has caused a need to study this concept carefully, given the high offsets and heave motions imposed by the vessel at the top of the riser. Fatigue verification is an important issue that requires accurate evaluation of the loading conditions that occur during the riser lifetime, and it also requires a precise knowledge of construction aspects that could decrease or change riser-materials resistance. Wave-Induced Fatigue Over the past few decades, Petrobras has acquired Campos basin wave, current, and wind data, resulting in a metocean database containing more than 7,000 records. Within these data, the occurrence of multimodal/multidirectional sea states was identified. To use this database in riser design, the in-house software tools for structural fatigue analysis were upgraded to consider bimodal/bidirectional sea states.