Page 436 - Pipeline Pigging Technology

Interpretation of pig survey results

INTERPRETATION OF INTELLIGENT-PIG

SURVEY RESULTS

INTRODUCTION

Recent years have seen a dramatic growth in the use of on-line inspection
technology for the revalidation of operational pipelines. Much of this growth
can be attributed to the success of high-resolution inspection technology in
providing cost-effective solutions to a range of pipeline problems; the
extensive application of these advanced services has allowed pipeline opera-
tors to confirm their accuracy and value.
As with all pigging operations, the technical details associated with the in-
field running of inspection tools is of great importance to both the inspection
contractor and the pipeline engineer, and adequate preparations in advance
of any in-field work are essential if expensive errors or delays are to be
avoided. Ultimately, however, the provision of inspection data in a final
report is the sole objective of running an on-line inspection tool in a pipeline,
and the value of the entire exercise is determined only by the quality and
nature of the information contained in the report.
This paper addresses a number of important aspects relating to British Gas'
inspection technology and to the eventual interpretation of data and prepa-
ration of inspection reports.

ACQUISITION OF PIPELINE DATA

In most circumstances, pipelines are selected for on-line inspection on the
basis of some form of risk assessment. This is usually related to considerations
for personnel safety and security of supply for gas pipelines, and with an
additional consideration for pollution in the case of liquid lines. Although such
assessments are often of a qualitative nature, an increasing number of pipeline

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