Pipeline integrity management systems rely on robust records and data so that the correct decisions are made. The Pipeline industry regulator is intending to ensure operators possess traceable, verifiable and complete (TVC) pipeline records as a basis for sound integrity and risk management. This is being driven by PHMSA in the notice of proposed rulemaking (NPRM) 49 CFR 192. In recent years, ROSEN has introduced RoMat PGS, an inline inspection service that is capable of determining yield strength and other information relevant for the calculation of maximum allowable operating pressure (MAOP).
The data obtained from multiple ILI services forms the fundamental basis for an engineering assessment that integrates ILI data and other pertinent information to assign pipe grade for each individual pipe, within identified populations, with minimized field verification efforts.
For pipeline sections with incomplete records, the addition of strength data to other available information allows reliable identification of different populations along a pipeline. This permits the operator to better optimize integrity and material verification strategies.
In early 2017, Xcel Energy and ROSEN partnered to conduct a materials characterization assessment of a 20″ gas distribution pipeline. This was the second time that Xcel had implemented the service. This pipeline was originally installed in two sections, in 1928 and 1947, and has since been largely replaced over time through a series of reroutes and replacements. With more than 25 different assumed construction dates, the RoMat PGS service was used to identify the different pipe populations and confirm that these align with available records.
This paper presents the results and subsequent analysis. It represents a significant marker in the industry, demonstrating how a cooperative and integrated approach using state-of-the-art technology, engineering processes, and material verification techniques can be used to improve the integrity of operators’ records. The paper discusses the various stages of the process, the significant findings, such as the types of pipes identified and their properties, and — most importantly — how the results were implemented into a pipeline integrity and risk management system.
