The integrity of aging pipeline systems is a major concern for operating companies. Because maintenance budgets are limited by economic constraints, operators must decide on how to best allocate the available maintenance resources. Optimal resource allocation involves the identification of high risk segments, and the determination of integrity maintenance activities for those segments that will lead to the highest reduction in overall operating risk.
To identify high risk segments it is necessary to quantify the probability of line failure and to evaluate the consequences associated with different types of failure. To identify optimal maintenance activities for high risk segments it is also necessary to quantify the reductions in failure probabilities associated with various candidate integrity maintenance activities. Under the sponsorship of a number of pipeline companies and Government Agencies, C-FER has initiated a Joint Industry Program (JIP), to develop quantitative risk-based models and software tools for estimating the current level of operating risk and the risk reduction potential associated with distinct segments of pipe within a pipeline system.
The key steps in the methodology are system prioritization and maintenance optimization. At the prioritization stage, segment-specific attributes are processed to provide an estimate of the failure rate for individual segments, and an estimate of the potential consequences of line failure. The failure rates are then combined with the loss potential into a measure of risk, and used to rank segments according to the calculated level of operating risk. At the maintenance optimization stage, a formal decision analysis approach is employed to identify the best maintenance strategy for high risk segments based on a comparison of the costs and risk reductions associated with each available option.