Learnings

Outcomes

Beyond the objective of determining fill material within a HP sleeve, guided wave also has the capability of assessing the condition of the carrier pipe, data that would be impossible to determine through current inspection processes. The excavation of an end seal to locate grout points would not validate that the sleeve had been effectively filled and could still be at risk of corrosion, this inspection will remove the requirement for assumption of condition in high pressure infrastructure.

Through the technical guidance and literature review consideration was given to further assets that could benefit of this type of inspection such as:

-        OLI4 pipelines

-        Sleeves

-        Overcrossings

-        Valve pits (Concrete transitions)

-        Lagged pipework (h/ex)

Adoption of this inspection technique would increase NGNs asset health data both in terms of increased sensitivity of already inspected assets, and new datasets for those not currently inspectable.  The additional benefit of the guided wave device is the modular construction of 6” and 4” collars allow flexible application using a limited number of inspection tools.

Lessons Learnt

Whilst the original project objective of fill material detection and assessment was driven by a clear asset safety requirement, further scoping would have concluded the necessity for grouting in general is dependent on corrosion of the carrier pipe. 

To that end, a lesson learnt for future projects is that the initial drive for a project may be more effectively managed and delivered through further assessment of the root cause of the issue.