A new leak detection system for long-distance pipelines utilizing soil-gas techniques

This paper presents a new leak detection system for a long-distance pipeline using soil-gas techniques. The new leak detection system runs underground along the nearby pipeline and consists of intermittent porous tubes connected in series with impermeable polyethylene tubes. Applying the new detection system to long-distance pipelines for leak detection minimizes the large number of soil-gas samples and analyses that are required when conventional soil-gas probes are employed. A mathematical model was developed for designing the distribution of airflow in the new detection system. Field leak tests were conducted using both conventional soil-gas probes and the new system. Results indicated that the effective detection distance of the new system was at least 30 m, while the effective detection radius from the conventional soil-gas probes is only ∼5 m.