ILI is traditionally used to detect, identify and size pipeline anomalies. ILI technologies can also be used to characterise the types of pipes contained within a pipeline and their material properties. ROSEN has developed the RoMAT PGS ILI service, which is able to non-destructively determine the strength of each pipe joint along a pipeline. To compliment the implementation of this ILI service, a process has been developed that provides operators with a comprehensive description of the different pipe populations and their properties. The process is based on an analytical assessment of multiple ILI data sets in combination with existing documentation and historical pipe data. It describes each population in terms of a characteristic ‘DNA’, which incorporates variables such as wall thickness, pipe length, weld type, strength and grade etc.
A combination of RoMAT PGS and the DNA process will provide operators with invaluable data for integrity assessment and management. The first and most transparent application is to address the issue of incomplete material records or unknown properties. Following characterisation of the present state, it is possible to identify integrity concerns or ‘red flags’ such as low strength pipes or populations, or areas along the pipeline with significant variation or inconsistent properties. The process can be linked to other integrity management issues such as inspection and assessment of corrosion or cracking to identify the specific pipe populations that are affected. Finally, it will be possible to apply the technology and DNA process to activities such as fitness for service assessments, where the use of measured properties could help reduce risk or the level conservatism.
The aim of this paper is to present the recent project experience from implementing RoMAT PGS and the pipeline DNA assessment process and discuss how it is applied to integrity management and assessment