Evaluating the Risk and Economic Implications of Pipeline Repair versus Replacement: A Case Study on Third-Party, Corrosion, and Design Issues

This study introduces a practical framework that integrates technical risk metrics with economic evaluation, enabling pipeline operators and infrastructure managers to make data-driven decisions. The findings support proactive maintenance planning, targeted risk mitigation, and strategic investment in critical infrastructure. By aligning safety priorities with cost-effectiveness, the study advances best practices in pipeline safety, risk management, and long-term asset sustainability. This study proposes an integrated risk assessment and economic evaluation framework to support maintenance decisions for natural gas transmission pipelines. Focusing on four primary risk indices—third-party interference, corrosion, design flaws, and human error—the research employs the Muhlbauer method to quantify risk levels across pipeline segments. To assess the economic feasibility of repair versus replacement, the annual uniform cost (AUC) method is applied. The case study involves a 258-km pipeline in Iran, divided into 688 segments, providing a real-world context with diverse environmental, technical, and human risk factors. Risk analysis revealed that although most pipeline sections maintained acceptable safety thresholds, several segments were significantly compromised by inadequate burial depth, high third-party activity, and subsurface corrosion. Although repair may offer lower initial costs, economic modeling indicated that replacement is more cost-effective over the long term, offering improved safety, reduced failure rates, and extended service life. This study introduces a practical framework that integrates engineering risk metrics with life-cycle economic outcomes, supporting informed decision-making in pipeline maintenance strategies. The approach is particularly useful in resource-constrained and data-limited environments, common in developing regions. By enabling targeted intervention and optimized resource allocation, this method aids pipeline operators, engineers, and policymakers in enhancing system reliability, environmental protection, and operational efficiency across aging energy infrastructure networks.