Page 443 - Pipeline Pigging Technology

Pipeline Pigging Technology

Reporting

The analysis and interpretation procedures result in a computer file
containing detailed information about pipeline flaws and their geographical
positions in the pipeline. The final step in the process is then to prepare a
report which will provide the pipeline operator with the necessary informa-
tion to take remedial action where required. This report can be formatted in
a wide variety of forms, and must be structured to reflect the overall condition
of the pipeline. In the case of pipelines containing relatively-small numbers
of reportable features, each flaw can be individually described in a written
report, giving the size and location of the feature. An example of this type of
report is shown in Fig.l.
However, where the number of reportable features is large, it becomes
necessary to process the survey data statistically to give the pipeline operator
an initial overview of the pipeline's condition.
The format of the report which provides this initial overview can be
tailored to suit the needs of individual pipeline operators, but experience has
shown that certain formats are of particular'benefit. One example of such a
report is shown in Fig.2, where the number of metal-loss features which
would fail at selected test pressures is shown against distance along the
pipeline. Another example is shown in Fig.3, where the metal loss is
described in terms of its depth and area, and is differentiated into pitting and
general corrosion.
In preparing reports for the pipeline operator, the principal concern is to
ensure that thie data type, and its presentation, are selected to satisfy the needs
of the pipeline engineers who are to perform remedial work. To this end,
British Gas has evolved a highly-flexible reporting structure which undergoes
constant review. Ultimately, however, it is the quality of information which
determines the overall value of the inspection service.

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