PSI - Issue 40

N.A. Makhutov et al. / Procedia Structural Integrity 40 (2022) 283–295 N.A. Makhutov at al. / Structural Integrity Procedia 00 (2022) 000 – 000

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Fig. 4. Set of inline inspection tools.

The national practice provides for inline inspection of up to 10 000 km of pipelines within a year. Automatic continuous recording of the measurement results allows to identify dangerous sections, cross-sections and areas of pipelines that do not meet the regulatory requirements. Number of such cases in a year reaches tens of thousands, which allows for design assessments of strength for each of them using only specialized software complexes. The inline diagnostics are supplemented with remote 3D measurements of position of pipes and wires using aerial photography, IR imagery and unmanned aerial vehicles. This allows for determination of ( τ S ) , h ( τ S ) . The next important element of technical diagnostics is detailed studies of pipeline condition at the most critical sections, when pipelines are broken into by test hole drilling and removal of protection. Mobile diagnostics systems are used for these cases (visual inspection, ultrasonic, eddy-current magnetic particle testing, optic measurements of actual position of pipes, measurements of wall thicknesses and diameters). Also, the most critical zones can be subjected to by Mahutov et al. (2021), Lisin et al. (2018) and Neganov et al. (2020) assessment of mechanical properties ( σ у , σ u ) of pipe steel and weld zones using direct and indirect methods. The first case includes cutting out of templates that are further used to make standard laboratory samples. Test results are used for evaluation of all strength and ductility properties. In the second case samples are not cut out and Brinell H в or Vickers H v hardness Н is determined. Strength properties are determined based on correlation dependences.     ( ), ( ) ( ), ( ) y S U S H B S V S F H H        (4) The above-mentioned technical diagnostic methods in the most critical pipelines (with high damage extent, under hard operating conditions) are repeated numerous times throughout the entire service life for 1 , 2 , …, . Such approach can be considered as transition from diagnostics to discrete condition monitoring. Tables 1 and 2 present the results of technical diagnostics and monitoring of two oil pipeline sections as an example.