This paper describes the high-resolution in-line inspection of a natural gas field pipeline network in Germany. The pipelines inspected have 4", 8" and 10" in diameter, with length up to approx. 1.6km. The inspections were done during a planned shutdown.

Due to various circumstances the pipelines are classified as “challenging to inspect” respectively “un-piggable” and the 4" and 10" lines have never been inspected before by using ILI tools since commissioning in 1982. The ILI challenges included: small diameter, lack of launch- and receive traps, partially incomplete as build information and an un-barred full-bore t-piece in the 10" line.

Considering the number of challenges – especially from ILI point of view – a turn-key project is described in which Intero and Storengy Deutschland Betrieb GmbH defined a common approach to perform an in-line inspection of the pipelines in question. All within the defined general technical and commercial conditions and of course in a safe manner.

The ILI campaign included high-resolution UTWM, XYZ and robotic MFL inspection.