Recently, a research team led by Prof. ZHANG Zhirong from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences has developed a high-performance laser-based Three-Dimensional methane gas cloud imaging telemetry system, which enabled visualizing micro-leakages, accurately locating leakage sources, and quantitatively retrieving emission rates.
The study was published in Environmental Science & Technology.
Methane leakage from oil and gas pipelines leads to safety risks and climate impacts. However, conventional pan-tilt unit (PTU)-based techniques rely on single-point measurements and are highly susceptible to wind interference, while other gas imaging approaches are limited by high cost, and constrained performance, making accurate and comprehensive detection challenging.
In this study, the team developed a detection method based on Tunable Diode Laser Absorption Spectroscopy (TDLAS), introducing dynamic scanning in the detection process.
Building on this method, the researchers further developed a methane imaging telemetry system that integrated an optical transceiver module, a hardware circuit module, a self-developed scanning PTU, and a host computer. The system adopted a coaxial transmit–receive optical path design, which enhanced the coupling efficiency of long-distance backscattered signals while reducing optical losses.
By combining scanning data with wind simulations, the team developed a flux-based inversion method to estimate methane leakage rates. This allowed accurate measurement of emissions and supported more efficient monitoring and control of pipeline networks.
This new system enables methane leakage detection to move from qualitative assessment to quantitative measurement, supporting more intelligent energy management.
Schematic diagram of a laser-based methane gas cloud imaging sensor system (Image by ZHANG Zhirong)
