Page 32 - Pipeline Pigging Technology

Why pig a pipeline?

Fig.4 Specialist pigging applications.
The use of intelligent pigs comes down to an assessment of the improve-
ment in safety and integrity of the line resulting from the detailed survey.
Presently, new offshore pipelines are normally designed to handle intelligent
pigs, and they are being run in the major trunk lines.

Other intelligent pigs

Several types of pig are under development. Amongst these is a neutron-
scatter pig to detect spanning and burial in subsea pipelines. In places along
a subsea pipeline the seabed can scour away leaving a vulnerable span. Spans
are presently found by external inspection using side-scan sonar or ROVs.
However, the neutron-scatter pig offers the possibility of reducing the
amount of external survey required and detecting with greater accuracy the
span characteristics.
Other examples include a video camera mounted on a tethered pig which
has been used for the internal inspection of pipelines close to the ends, and
a curvature-detection pig used to detect excessive pipeline strains due to frost
heave and thaw settlement in Arctic areas.

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