FLOWLINES & PIPELINES
New pig tracking system
provides real-time information
Advent of more sophisticated inline tools
necessitates advanced monitoring systems
Every day brings news of operators charting remote territory to unearth new sources of oil and gas. As they delve deeper subsea and into diffcult-to-access terrain, the challenge of in- stalling and maintaining complex pipeline networks continues to escalate. To make certain that pipelines are well maintained
regardless of location, the industry has developed sophisticated
remote-controlled systems to inspect them and to isolate pressure
in sections needing repair.
Critical to the successful completion of isolation operations carried out to facilitate safe repair and maintenance of pipelines is the
ability to control, track, and monitor pressure isolation tools. Tracking and monitoring conventional pigs, high resistance and intelligent pigs, and other inspection geometry tools used during pipeline
cleaning and inspection operations is also important.
Historically, pig tracking methods have been limited by the level
of the frequency of the signal emitted by a transmitter installed on
the pig. A fxed frequency signal generated by the transmitter was
detected by a receiving device located on – or in proximity to – the
pipeline. Before a pig run, the systems were put in place and a sig-
nal frequency was selected in accordance with the type of tracking
As a general rule, a higher frequency is required to track pigs
moving at a higher velocity in order to ensure that the pig is detected as it passes a detection unit. Lower frequency settings are used
when a pig is to be monitored at a fxed location for an extended
period. Because the battery life of the transmitter is in nearly direct
proportion to the frequency of the signal, the higher the frequency
rate of the signal, the shorter the battery life. This means that the
ability to track and monitor pigs traveling at higher speeds or for
longer periods is signifcantly reduced.
To overcome these limitations, T.D. Williamson (TDW) developed
the Smart Track remote tracking and pressure-monitoring system.
The system uses through-wall communication technology to remotely
track and monitor a pipeline pig or any other inline intelligence-gathering device, such as a geometry inspection or magnetic fux leakage
(MFL) tool, as it travels through an oil or gas pipeline, regardless of
the location of the line.
Whether the pig is inserted into a subsea, topside or onshore pipeline,
the system pinpoints its location and identifes it via a unique identifca-tion (ID) code attached to the pig’s transponder, and monitors pipeline
pressure. Should the pig stop or become stuck, it can be located quickly
so that steps can be taken immediately to rectify the situation. It is also an
effective means of tracking specially designed pigs in sequences used to
food, clean, and gauge pipelines during pre-commissioning.
The Smart Track system enables remote tracking and pressure monitoring
for a wide variety of inline tools, from pressure isolation devices to cleaning pigs and inspection tools.
Tracking progress: The specialist shown here tracks a pig’s progress using a personal digital assistant (PDA) in conjunction with the Smart Track