Ethylene Pipeline Leak Detection
May 24, 2016

SENSORNET GAS PIPELINE LEAK DETECTION

This test was carried out in Q2 2006 for the Korean National Gas authority in conjunction with Sensornet’s Korean partner company SOAM Consultants Co. The aim of this project was to detect leaks in a gas pipeline using compressed air using the Sentinel DTS. Note with compressed air temperature changes are very small (2°C from ambient conditions). The setup of the system was as shown in the following two images:

SOAM_1

Installation map of DTS cable for the gas leakage detection test

SOAM_2

Custom-made structure for installation of DTS cable around gas pipeline

SUMMARY OF TEST PROCEDURE
  • A Sensornet Sentinel DTS system was used to monitor the temperature thermal response of the system due to gas expansion as a result of a leak occurrence
  • Compressed air was used as the gas contained in the pipeline. As the compressed leaks from the pipeline it cools on expansion – but only be a small amount (2°C)
  • A section of pipeline with fibre optic cable installed in close proximity to the pipeline was buried underground. The pipeline contained valves to enable simulation of a leak event – by opening the valve a gas leakage could be created.
  • The fibre optic cable was installed as close together as possible to the pipeline to accurately detect a result, using a frame to tie the cable to for easy installation.
  • A leak was created by opening a valve (by use of a handle extension to the valve) in the buried pipeline.

The installation procedure is shown in the following diagrams:

SOAM_3

Installation procedure at the testing site

SOAM_4

Simulation by injecting compressed air into gas pipeline for monitoring temperature change

RESULTS

SOAM_5

Temperature change of the gas pipeline under its leakage along with time pass at vertical view (120 l/min)

SOAM_6

Temperature change of the gas pipeline under its leakage with time. Leakage position is displayed as above.

CONCLUSION

The Sentinel DTS effectively detects leaks using only very small temperature changes occurring due to expansion of gas causing a temperature drop (of approximately 2°C) in the surrounding environment (an area 40cm x 100cm) of over a period of approximately one hour.

Please contact a Sensornet representative or SOAM Consultants Co. Ltd for more information.

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