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 3D 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, existing detection methods remain inadequate. 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.
The approach developed in this study, based on Tunable Diode Laser Absorption Spectroscopy (TDLAS), effectively addresses this challenge by introducing a dynamic scanning method for the detection beam.
Building on this strategy, the researchers further developed a methane imaging telemetry system that integrates an optical transceiver module, a hardware circuit module, a self-developed scanning PTU, and a host computer. The system adopts a coaxial transmit–receive optical path design, which enhances the coupling efficiency of long-distance backscattered signals while reducing optical losses.
In addition, by combining path-integrated concentration data obtained through scanning with wind field simulations, the team established a leakage rate inversion method based on flux principles. This enables accurate quantification of methane emissions and provides a new technical route for intelligent monitoring and precise emission control in pipeline networks.
Compared with conventional PTU-based equipment, the new system demonstrates many advantages. It enables the transition of methane leakage detection from qualitative assessment to quantitative, contributing to more intelligent management of energy systems.
Schematic diagram of a laser-based methane gas cloud imaging sensor system (Image by ZHANG Zhirong)
