TPi March 2013

Optimising pipe fit-up and logistics improves welding productivity By Dr Richard Gooch, director of technology at Optical Metrology Services (OMS) Ltd

Laser-based measurement tools can be used to measure the IDs and WTs of pipe ends in rapid time. Typically, several thousand IDs of a pipe can be measured in less than half a minute, enabling hundreds of pipe ends to be measured in a single shift. This means less time on site, minimising project delays and costs for the pipelay contractor. Laser- based measurement tools are also very accurate (typically to 0.05mm). Using tools such as these saves a lot of time. Being able to measure up to 400 pipe ends in a single day is at least three times faster than using regular, conventional measurement tools (eg caliper gauges), which only measure at a few discrete locations around the pipe. Pipelay contractors are therefore able to keep their project schedules on track and, because some projects involve measuring more than 2,500 pipes, the time and cost savings are significant. Data from laser-based measurement tools can be made available to pipe optimisation software, which will include some sort of simulation or sequencing software, as is included

In oil and gas pipeline projects, the welding of fatigue- sensitive SCR and flowline pipes to tight specifications is absolutely critical. Counterboring the pipes might not be a viable method of controlling pipe geometry due to cost considerations or to limitations on pipe wall thickness. So how can pipeline contractors ensure that pipe fit-up, welding and pipelaying processes run smoothly with minimal interruptions? Dr Richard Gooch, director of technology at Optical Metrology Services (OMS), discusses how software and laser-based measurement tools can help to optimise pipe fit-up, reduce welding time and minimise production delays. F or oil and gas companies, pipeline welding is a high precision task that cannot afford any delays. If pipes fit together poorly due to geometrical defects, this can lead to repairs and rework, which impacts tight production schedules.

In order to prevent bottlenecks during the welding process and minimise project delays and risks, oil industry owners, pipelay contractors and welders need to capture, record and analyse pipe end geometry quickly and accurately. This measurement data, if used in the correct way, can then help to ensure that pipes delivered into the bead stall will fit together within the specification requirements for welding. Typically, end dimensioning and fit-up involves two main steps: measuring and fit-up. The measuring stage involves the actual collection of pipe measurement data. Here, automatic, laser-based measurement tools can be used to measure the geometrical features of pipe ends, normally performed onshore, although this process sometimes needs to occur on a cargo barge.

Pipe ends with rotation marks on the ready racks prior to welding

65

www.read-tpi.com

March 2013 Tube ProducTs InTernaTIonal