Pipeline leak detection

Optical fiber: a revolution for pipeline leak detection

Pipeline leak detection is so important… Even though pipelines are still the safest way to transport oil and gas products, spills and leaks may occur. These incidents can have an important environmental impact, incur cleaning costs, and deteriorate the company’s image.

Several technologies have been developed to monitor the pipelines to detect or prevent leaks (ultrasounds, flow monitoring, smart pigs…). Optical fiber recently brought a revolution to the sector: we can now have a distributed measurement all along the line using telecommunication fibers, giving us every foot the temperature, strain, and vibrations of the pipe.

Most optical leak detection systems today use Distributed Temperature Sensor (DTS) monitoring. When the product is at a different temperature than the exterior environment, a passive monitoring system will be able to rapidly detect leaks by looking for hot or cold spots along the line. This type of measurement has an extremely low false alarm level, especially if there is a big difference in temperature (LNG, heated oil, pressured gas with Joule Thomson effect…).

But when the product is at the same temperature as the exterior environment, a passive DTS monitoring will not work. This is why Cementys developed an Active DTS monitoring system: in this case, we use a metallic cable to heat the line, to analyze both the temperature and the temperature variation. This real-time analysis gives out the thermal capacity of the environment, directly linked to the presence of oil.

For long lines, Cementys developed the Transient Monitoring System. To use an active DTS system, one will need power to heat the line (around 1W per meter). We can see that this solution is hard to implement for lines longer than a mile. Our Transient Monitoring System analyzes the temperature variations due to daily and seasonal changes. After a learning period, the system is capable to detect a change in behavior, therefore, a leak.

Thanks to those technologies, Cementys can help you to monitor all of your lines.