Leak Detection Culture

The API recommended practice urges pipeline operators to develop a strong culture of leak detection just as they have embraced other safety measures for years. A leak detection program should encourage a commitment to safe pipeline operations, as well as the best leak detection technologies. Top management should champion this program, and all employees should understand and support it.

Pipeline operators should weave the leak detection program into the fabric of their operations and strictly control the management of change. The pipeline operator should clearly define roles and train personnel as needed. Above all, every employee should have the authority to stop unsafe work, and every operator should have the authority to shut down a pipeline if a leak is suspected without fear of reprisal.

While the recommended practice also talks about performance in the control room, this review will focus more on the recommendation’s treatment of leak detection systems (LDS). Topics covered in this RC that affect leak detection include;

  • Selection of leak detection system
  • Integration of leak detection system
  • Measuring performance of leak detection systems
  • Reporting
  • Training and testing
  • Management of change
  • Ongoing improvements, and measuring their progress

Leak Detection Strategy

The leak detection strategy is a written document that should cover all aspects of the Leak Detection Program (LDP). The objective is meeting and exceeding the minimum regulatory requirements by improving the performance of an LDS, and adding a better LDS or a complimentary LDS where the risk evaluation calls for enhanced performance.

The strategy should set specific aims such as targets for performance aspects of the LDP. For example, the detectable leak rate or volume, and limits for false alarms. Targets for improved leak detection metrics could be:

  • Reduced false alarms to improve operator confidence
  • Reduction in detection alarm thresholds
  • Leak location improvement
  • Faster detection time
  • More accurate leak size estimates

The leak detection strategy document should address leak detection requirements during the design of new pipelines and for changes to existing pipelines. It should define why a particular LDS is chosen based on the risk analysis and best industry practices. The Recommended Practice (RC) proposes a strategy that includes methods that provide continuous leak detection and considers where the implementation of multiple LDSs that complement one another can provide a worthwhile advantage. The strategy should consider using an LDS that can be tested, and whose performance can be benchmarked against leading KPIs such as false alarm rate, sensitivity, and lagging KPI’s such as system failure rates and downtime. The strategy should include a plan to test the LDS periodically.

This approach holds great promise for continuous improvement of leak detection systems. It provides opportunities for leak detection vendors and the pipeline operators to identify where they can gain the most improvement first. Whether it is a better measurement, better communications, more intelligent detection algorithms or improved tuning.

The internal and external review process in a leak detection strategy will help identify and define the benefits of the improvement efforts over time. I will not cover LDS selection process based on risk in this review, instead, I will look setting targets for LDS performance, things we can measure, and useful KPIs that can be used to document how the LDS is improving over time.

Performance Targets Metrics and KPI’s

The metrics are quantified by the KPI’s. For example, LDS sensitivity is a metric that measures leak size and can be tracked by a KPI. The leak detection strategy should set performance targets using such metrics as reliability, sensitivity, accuracy, and robustness. The RP suggests several approaches including using API RP 1149 to set metrics for sensitivity over time. I personally see only limited value in RP 1149. It is a theoretical exercise that can be inaccurate, and we cannot know the accuracy of the estimation. The RP 1149 calculations are for steady state operations only and do not account for temperature influences. Few pipelines are in a steady state very often, and temperature can affect flow imbalance measurements. A better approach may set targets based on the operator’s own experience and specific knowledge of the pipeline. The best approach may be performance observation, e.g. analysis of the historic performance of the LDS and/or testing designed to establish the performance of the LDS.

Read Part 3

References

  1. American Petroleum Institute. (December 2015) Recommended Practice 1175, (First Edition), Washington, DC: Author
  2. American Petroleum Association. (2014). Recommended Practice 1175, Pipeline Leak Detection Program Management (2st ed.). Washington, DC: Author

A look Inside API recommended Practice 1175 Series

A Look Inside API Recommended Practice 1175, Part 1
A Look Inside API Recommended Practice 1175, Part 3
A Look Inside API Recommended Practice 1175, Part 4
A Look Inside API Recommended Practice 1175, Part 5
A Look Inside API Recommended Practice 1175, Part 6
A Look Inside API Recommended Practice 1175, Part 7
A Look Inside API Recommended Practice 1175, Part 8

Categories: Best practice advice Industry update

By: Atmos International
Date: 17 April 2019