Testing the Limits of DAS as a Leak Detection Tool for Pipelines

Over the last few years, DAS technology has been successfully commissioned as a monitoring solution for the pipeline industry. However, the success of these systems has mainly been through their use as a security monitoring tool — autonomously detecting things like the movement of vehicles, ground excavation in the vicinity of the pipeline or other third-party intrusion (TPI) incidents.

Today, when it comes to the integrity of pipelines, researchers are evaluating whether DAS can be applied to other aspects of continuous real-time evaluation. In particular, a lot of this research has focused on whether DAS can be utilised as a leak detection tool.

For pipeline operators leak detection is one of the biggest strategic priorities, due to the significant environmental damage, and huge costs, that can result from leak incidents. Historically, pipeline leak detection monitoring has been achieved with the aid of a number of technologies, including: mass balance systems, acoustic pressure wave monitoring systems, and real-time transient monitoring systems.

But following incidents like the Keystone Pipeline leak in North Dakota last year, there has been a demand for a more complete solution. With so much at stake this is to be expected – with research for new technologies focused on increasing both the speed and accuracy of leak detection. As a result, DAS has been receiving a lot of interest as an alternative leak detection system.

While DAS has been subject to increased interest in leak detection scenarios, it remains a relatively new concept. And one with little in the way of positive documented evidence. While recent experimental evaluations have demonstrated a certain level of potential, these studies have been conducted in controlled laboratory-based environments.

Of course, the elephant in the room when it comes to doing more meaningful testing is how to simulate a representative leak scenario. No one wants to deliberately cause a leak, and operators understandably don’t want to intentionally damage their pipelines. But in order to better understand DAS’ capabilities, the team at Fotech went and found an opportunity to test DAS on a real-world, commissioned pipeline.

Using a 35km stretch of pipeline, the operator agreed to use water as a substitute for the fuel product usually transported on the pipeline. Simulated failure orifices were created at key points on the pipeline to conduct an in-depth analysis of DAS’ ability to detect some of the key indicators of a leak. These include negative pressure waves, temperature changes in the surrounding soil, and the vibrations caused by the liquid being forced through the pipeline rupture.

Over the course of a week numerous simulated leaks were conducted. And the results we saw were extremely positive. The system under testing correctly identified the onset of forty five individual leak simulation events, with zero false positives or true negatives. More importantly the results showed that three of the key leak signifiers can be detected with a high degree of confidence.

This testing is a huge breakthrough for the industry. In these real-world tests DAS demonstrated considerable value as a pipeline leak detection monitoring platform, with a number of key benefits when compared to conventional solutions.

We’ve published a full breakdown of the test in a technical paper – which you can read here. And if you want to know more contact us to speak to the team behind the testing.