A Framework for Risk-Based Integrity Assessment of Unpiggable Pipelines Subject to Internal Corrosion

Abstract

Many pipelines are unpiggable, which means they cannot be examined by in-line inspections (ILI). Existing industry practice for integrity assessment of unpiggable pipelines is not risk based, which precludes optimal allocation of inspection and maintenance resources. A framework for risk-based integrity assessment of unpiggable pipelines subject to internal corrosion is presented. The framework considers localized corrosion and microbiologically influenced corrosion (MIC) by combining flow and corrosion analysis for probability and consequence analysis as part of a quantitative risk analysis. Primary results of the application of the proposed framework show that it is applicable and beneficial for inspection and maintenance cost optimization.