Laser measurement systems (fixed and portable) have been developed by Tenaris to perform an automatic dimensional inspection of pipe ends.
Measuring OD, ID and WT, this tool is helpful not only for pipeline producers, which can have a better knowledge of the manufactured pipe ends' geometry, but also for the laying companies and for the end users, giving useful information in order to perform more efficient pipe line-up prior welding.
Since fatigue is normally the main limiting design criterion for fatigue sensitive products like flowlines and risers, representing a major engineering challenge, one way to minimize the risks of girth welds' fatigue failure is to reduce the pipes abutting Hi-Lo. This task could be accomplished by the use of laser pipe ends measurements analyses together with dedicated software.
Improvement of line-up pipe is very important for offshore oil recovery industry, where the fatigue requirements of pipelines subject to high dynamic loads are continuously increasing, as the exploitation is moving in harsh environments.
This paper describes the validation process and the implementation of automatic measurement systems for the inspection of the pipe ends' dimensions with high repeatability and precision. In addition, the following software applications are showed:
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Division in families: determination of pipes groups according to their OD/ID/WT tolerances;
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Best Matching: search of the alignments which minimize pipes abutting Hi-Lo;
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Counter-Boring: analysis of the best pipe ends ID and/or OD to be machined and of the residual WT forecast after counter-boring.
The increasing requirements of risers and flowlines subject to fatigue loads are leading to an interest of pipe ends laser measurements, aiming to enhance girth weld manufacturing and consequently their fatigue strength.
Fatigue is becoming one of the most important aspects to be taken into account in the design of offshore floating production systems (e.g. Spar, Semi-submersible, Tension Leg Platform (TLP), Floating Production Storage and Offloading (FPSO)). Due to their highly compliant nature, fatigue loading is accentuated particularly if compared to traditional fixed-bottom platforms. Fatigue loading arises due to production systems' motions that are caused by current action and waves. Some of the most fatigue critical components of these systems are the import and export Steel Catenary Risers (SCRs). Wave motions transmit significant fatigue loading to SCR, in particular at the touchdown location where the nearly vertical riser curves to join the pipeline or flowline on the ocean floor. In addition, the riser can experience fatigue loading due to vibrations induced by sea currents, like Vortex Induced Vibrations (VIV). These vibrations can occur at any number of locations along the riser length depending on the dynamic response of the structure and the current profile.
