Case Study: Drone-Based Methane Detection in Urban Gas Pipeline Inspection Using BL-CH4 MINI in HongKong

Background
Urban gas pipelines are critical infrastructure for city energy distribution, but they often run through densely populated and hard-to-access areas. Traditional pipeline leak detection methods—such as handheld detectors and foot patrol—are time-consuming, labor-intensive, and prone to blind spots.

Challenge
A municipal gas utility in Hongkong faced growing challenges maintaining inspection frequency and leak detection accuracy across its aging underground and above-ground pipeline network. Increasing regulatory pressure and public safety concerns demanded a more efficient and reliable solution.

Solution: Deploying BL-CH4 MINI on Dji Dock 2
The utility deployed drones equipped with BL-CH4 MINI, a lightweight and highly sensitive laser-based methane detection sensor. Based on TDLAS (Tunable Diode Laser Absorption Spectroscopy), the sensor detects methane gas by measuring path-integrated concentration (PPM·m) from a distance.

Inspection Workflow

Mission Planning: Using GIS maps, drone flight paths were pre-programmed along pipeline routes including overhead pipelines, bridge crossings, and utility corridors.

Aerial Patrol: Drones flew 10–30 meters above the pipeline routes, scanning continuously with real time methane concentration data streamed to the ground station.

Leak Identification: Detected anomalies were geotagged and automatically flagged for follow-up.

Reporting: After each flight, a full inspection report was generated including concentration data, GPS coordinates, and leak severity levels.

Results

Speed: Daily inspection coverage increased by over 5× compared to traditional ground patrol.

Accuracy: Able to detect methane leaks as low as 5 PPM·m, even in windy urban environments.

Safety: Eliminated need for inspectors to enter high-risk or difficult-access areas such as overpasses, rail corridors, or beneath elevated roads.

Cost Efficiency: Reduced inspection costs by 40% over a six-month period.

Conclusion
The BL-CH4 MINI sensor, when paired with drones, proved to be a transformative solution for city-wide gas pipeline inspection. It enabled fast, precise, and safe methane leak detection, significantly improving operational efficiency and public safety.