A major pipeline operator was negotiating the purchase of an
established gas gathering pipeline system.
survey of 12 miles (19km) of the line was carried out and
a number of faults located to an accuracy of better than +/-
2 feet (0.6 metres). 2 of these were excavated and found to
have large areas of missing coating and severe corrosion -
up to 60% metal loss.
These faults clearly originated from the construction of the line
but had not been found using traditional pipeline survey methods.
It was accepted by the vendors that the other large faults located
were probably in a similar condition and this formed the basis for
calculating the likely cost of bringing the whole system up to a
proper operational standard.
The whole appraisal operation - survey, excavations and assessment
- was completed in less than 1 day.