March 2013 Tube ProducTs InTernaTIonal
65
Optimising pipe fit-up
and logistics improves
welding productivity
By Dr Richard Gooch, director of technology at Optical Metrology Services (OMS) Ltd
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?
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.
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
Pipe ends with rotation marks on the ready racks prior to welding
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.
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.
