Öl und Gas

Remaining life assessment for transmission pipelines

Planning for extended life using proven techniques

An operator needed to demonstrate to authorities and other stakeholders the expected remaining technical life of its entire pipeline network. The company needed a deep understanding of the level of threat to its operations and what risk mitigating actions it would need to conduct to ensure safe and efficient operations.

DNV GL solution
DNV GL identified relevant pipeline integrity threats and conducted a a technical analysis on the impact of those threats on the life of the pipeline network.  A methodology framework was established to assess the effect of significant risks, which revealed that the dominant threat was corrosion. The work included a sensitivity study into the impact of future degradation of corrosion barriers.

Outcome and benefits
It was found that, with appropriate inspection and maintenance, the technical lives of the network pipelines could be expected to exceed the currently declared end of life by at least 100 years — some 250% of the original design life.  The study provided the operator with valid reasoning for adjustments to the asset depreciation rate used for determining residual asset values and the methodology framework provided a consistent process for assessing the operator’s other network assets.