Page 119 - Pipeline Pigging Technology

Pipeline Pigging Technology

Construction and environmental data

This information, added retrospectively, is maintained manually and
allows the system to validate inspection data and to prepare analysis sheets
with all relevant pipeline information. It is however not intended to hold a
complete history of the pipeline construction in this category. The following
information is held for each pipeline:

pipe route (UTM co-ordinates, water depths);
physical characteristics (wall thickness, coatings, features such as
anodes, etc.);
construction data (manufacturer, laying, trenching, etc.);
environment (sea currents, waves, etc.).

Inspection data

The inspection details, for each pipeline, are held in a hierarchy of records
linked to the main pipeline record. The general details of the inspection, such
as: scope of inspection, dates, contractor, etc., are held in the inspection
record. Then, depending on the type of inspection, further details are held in
a variety of subordinate records.

Acoustic inspection results:
- pipe burial and trench condition;
- observations: free spans, scars on sea bed.
ROV inspection results:
- observations: damage, anode condition, free spans ...
- longitudinal and transverse trench profiles;
- cathodic protection level;
- videotape references.
Internal inspection results:
- internal diameter restrictions;
- pipe wall anomalies

Some analysis functions (such as suspension history) allow the character-
istics of an observation (length, height,etc.) to be compared over the years.
Because of the inaccuracy inherent in all pipeline positioning systems, the PK
value supplied by the inspection contractor will not exactly match those of
previous inspections. By comparing the observations it is possible addition-

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