TPi March 2013

number and end designator of the pipes and whether any were ‘anode’ pipes.

in OMS’s SmartFit TM program. This software uses pipe measurement data to predict and control the fit-up, before the pipes are brought into the bead stall for welding. This can avert production issues relating to poor fit-up and manages the assembly of problem pipes in order to maximise welding productivity. Measure, mark and fit-up Each pipe end is measured, identified and entered into the software. The software analyses the fit-up of pipes and allows the operator to mark the best rotational position on each pipe end. In the bead stall, these marks are aligned to immediately achieve the best rotational position so that misalignment is minimised. Any problem pipes that won’t fit at a specified HiLo are also indicated and are re-sequenced or removed completely so that fit-up problems do not occur in the bead stall. Production delays due to mismatched pipes are avoided. Experience shows that with typical flowline HiLo limits and using typical seamless line pipe that has not been counterbored, fit-up issues can occur regularly depending on the HiLo requirement. For a HiLo of around 1 to 1.2mm, problems are likely to occur every 10 to 20 pipes (this varies according to the exact project and the type of pipe). Using pipe optimisation and simulation software enables the required HiLos to be achieved in the bead stall without trial and error. But when pipes will not fit, this will be indicated and the problem pipe can be taken out of sequence, therefore avoiding any problems in the bead stall. For a HiLo of 0.8 to 1mm, problem fits will occur in 20 to 50 per cent of the cases. Many pipelay contractors are benefiting from working closely with experienced, independent measurement specialists such as OMS, helping them to avoid a range of potential issues such as wall thickness problems in SCR and flowline pipe, counterboring of SCR pipes and poor fit up on board ‘J-lay’ vessels. OMS has already completed more than 30 major projects with customers using its SmartFit software, which optimises pipe fit-up and HiLo. SmartFit comprises a laptop computer system used prior to the pipe firing line, for example, in a ‘ready rack’ on the pipelaying vessel. In one particular pipe fit-up project, OMS project managed the complete pipe measurement, mark up and fit-up process, both onshore and offshore. After the pipes were measured onshore and marked up, they were transported by cargo barge to the laybarge. Using cranes, measured pipes were offloaded in small batches of 15-20 pipes to a pipe holding area on the main deck of the laybarge.

Using SmartFit, the pipes were sequenced to obtain best fit- up. The pipes were then numbered for the riggers.

The riggers loaded the sorted pipes in the correct sequence to the pipe bevelling inbound rack. After bevelling, OMS inspectors marked up the pipes with rotation and datum marks. The spacer crew were then able to correctly align these rotation marks, which minimised the HiLo. This ensured that the project HiLo specification was met and that welding problems were avoided prior to the firing line. About Optical Metrology Services Optical Metrology Services Limited (OMS) provides pipe measuring products and services, specialising in measuring equipment and consulting services for use within the pipe manufacturing and pipeline construction sectors, both onshore and offshore. A key focus for OMS is the dimensional measurement of oil and gas pipes or other structures such as military gun barrels, processing industry tubes or manufactured cylindrical objects, where dimensions are critical.

Optical Metrology Services Ltd – UK info@omsmeasure.com www.omsmeasure.com

Here, an OMS inspector noted down the pipe numbers of the stack, creating a visual representation of the physical position,

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Tube Products International March 2013

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