Cracking can be caused by pipeline defects – such as dents with metal loss, rerounded dents and dents with gouges. Often caused by third parties during excavation and construction activities, these kinds of anomalies have linked to a greater probability of pipeline failure by recent research.
Although operators have worked diligently to prevent third party damage to their pipelines, the problem still persists. For example, in the US, third party damage is associated with one-fifth of all significant incidents that have occurred on liquid and natural gas transmission pipelines in the past 20 years. Similarly, the EU’s petroleum industry watchdog, Concawe, has reported that since 1971, ‘third party interference’ has been the chief cause of failures in European cross-country liquid pipelines.
Fortunately, better assessment techniques are helping to reduce incidents that are related to third party damage. Specifically, inline inspection (ILI) tools are widely considered the best method for detecting mechanically damaged regions –including dents, rerounding and gouges.
Now, a white paper examining the efficacy of ILI technology that acquires multiple datasets in a single survey has providing increased understanding of how to detect and assess the severity of mechanical damage.
Multiple Dataset Inline Inspection for Mechanical Damage Assessment illustrates how a geometry and magnetic flux leakage (MFL)-based inspection platform improves the detection of third party damage, while also producing supplemental information to help determine the severity of damaged locations. This means that operators can better prioritise repairs, optimise precious resources and concentrate on their most critical anomalies.
The above paper is based upon research conducted by T.D. Williamson, Inc. (TDW), a global pipeline services provider.To test the field-readiness of a multiple dataset platform tool configured with a number of sensing technologies, TDW used Battelle’s mechanical damage machine, which was capable of inserting 34 dents and gouges into a new joint of X-42 grade, 16 in. dia., 0.250 in. thick pipe. Battelle’s machine simulates the digging arc of a backhoe and the more linear action of bulldozers, graders and other equipment.
TDW then inspected the joint using its multiple dataset (MDS) platform, which was configured to include:
- A helical or spiral magnetiser (SMFL) to detect and quantify axially oriented features.
- A high-field axially-oriented magnetiser (MFL) to measure volumetric metal loss.
- A low-field magnetiser (LFM) to identify magnetic property variations and residual stresses.
- High-accuracy deformation sensors (DEF) to locate and size dents.
- Proximity measurement sensors providing internal/external discrimination (IDOD) and internal surface condition.
The white paper explains how the MDS tool and advanced analytics demonstrated improved detection, characterisation, sizing and prioritisation of defects that arise from mechanical damage. In addition, the MDS tool was able to confirm the absence or presence of interacting threats within a dented region.
According to Chuck Harris, TDW Strategic Commercialisation Manager, technologies and advanced analytics that improve the accuracy of damage assessment represent a “leap forward in solutions capable of meeting the demands of pipeline operators worldwide.”
Adapted from press release by Anna Nicklin
Read the article online at: https://www.worldpipelines.com/equipment-and-safety/04082016/td-williamson-report-explains-efficacy-of-inline-inspection-technology/