Novel methods for safer and more efficient oil and natural gas pipelines
Volumetric surface defects as a result of corrosion or erosion-corrosion processes are one of the main causes of pipeline accidents. The use of composite materials to repair damaged pipelines shows considerable promise. However, numerous standards associated with such repair are based on simplified approaches and do not consider the stress-strain state of damaged areas. With this in mind, the EU-funded INNOPIPES (Innovative nondestructive testing and advanced composite repair of pipelines with volumetric surfaces defects) project aimed at improving infrastructure by making existing pipeline systems more reliable. In all, 411 full-time equivalent months were used for short-term staff exchanges and networking activities between EU and third country organisations. Two training events were carried out in Poland and Russia. At these sessions, 26 lectures on non-destructive testing and advanced composite repair were presented by experienced researchers from participating organisations and leading researchers from host countries. The INNOPIPES team made recommendations to apply long-range ultrasonic testing technology for pipeline diagnostics. It developed various analytical, numerical and numerical-experimental methods to accurately characterise damage found on pipelines using the long-range ultrasonic technique. Impulse excitation and inverse methods based on vibration tests were developed to provide accurate, reliable and effective non-destructive characterisation of elastic, hysteretic and viscoelastic material properties. Also developed were a new procedure to determine the remaining strength factor for pipelines subjected to local metal loss and a design methodology that defines the parameters of composite repair. Researchers devised different analytical and numerical models that describe a stress-strain state in the linear and elbow sections of a pipeline. A methodology was created to experimentally characterise the effectiveness of the developed composite repair of damaged pipe specimens. Results demonstrate the effectiveness of the developed repair technology. Lastly, four workshops helped to disseminate project results. INNOPIPES improved existing methods and developed new ones to better detect and repair volumetric surface defects. This should ensure efficient and safe operation of current pipeline networks spanning Europe.
Keywords
Pipelines, volumetric surface defects, stress-strain state, INNOPIPES, composite repair