PR-454-134505-R01 Strain-based Design and Assessment - Integrity Management

Abstract

The objective is to develop an integrity management approach that would meet industry needs and could be the basis for codes and standards development by relevant pipeline code commit-tees. The approach is to collaborate with the PRCI SBDA committee to come up with a frame-work that could meet industry�s needs to ensure the safe and reliable operation of pipelines that may be subjected to significant ground deformations. This report contains a detailed review of existing integrity management codes and pipeline design codes to establish the guidance that is available for the integrity management of pipelines that have been designed using strain-based design methods. It covers integrity management of high strains in new and existing onshore and offshore pipelines. This report presents a review of the main causes of high strains and describes the critical limit states considered in strain-based design, which may also be used to evaluate a pipelines continu-ing fitness for service after a high strain event. It describes the tasks that can be performed dur-ing each phase of a project to ensure the integrity of a new Strain Based design (SBD) pipeline. The additional integrity challenges associated with a high strain event in an existing non-SBD pipeline are presented. A detailed review of the capability of existing in-line tools to measure axial and bending strain is presented. Preliminary reviews of available external tools and technology that can be used to es-tablish the material properties of the line pipe and weld material, which are needed to establish the fitness for service of an existing non-strain-based design pipeline, is presented. A preliminary review of the methods used to detect and measure defects in girth welds and confirm that the allowable defect size has not been exceeded, is also presented. A flowchart covering the key actions and decisions to be made by a pipeline operator in the event of a high strain event is also included. This report presents recommendations for future study and development work based on the guidance and technology gaps identified during the study.