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Detection and quantification using drones and similar technologies.

The detection and quantification of methane emissions in gas and utility networks is crucial for operational safety and regulatory compliance.

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Sanket Bhatia

SensorX Solutions AG

Published In

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Switzerland's leading journal for the water and gas sectors, published by SVGW.

Published on: June 8, 2026

Methane is among the most potent greenhouse gases. In gas supply networks, pipe damage, valve malfunctions, or sealing problems can lead to methane emissions. While previous inspection methods were primarily qualitative, current frameworks such as OGMP ( Oil and Gas Methane Partnership ) 2.0 and the EU Methane Regulation (EUMR) require a detailed determination of emission quantities to validate emission reports. The EUMR distinguishes between Type 1 inspections (qualitative search) and Type 2 inspections (quantitative assessment).

The aim of this technical report is to present methods and technologies that enable both leak detection and quantification of methane emissions while supporting regulatory requirements.

   Regulatory framework   

OGMP 2.0

OGMP 2.0 requires an increasing level of detail in the documentation and validation of methane emissions. Key elements include the following points:

  • Periodic inspections of the network with documentation of screening and follow-up activities

  • Classification of emission sources and quantitative estimates

  • External verification of reports according to standardized protocols

EU Methane Regulation (EUMR)

The EUMR stipulates the following:

  • Regular qualitative leak detection in the distribution network (e.g. visual inspection, screening)

  • Quantitative measurements of detected emissions to create quantity estimates

  • Thresholds for assessing the severity of emissions

  • Detailed documentation of the measurement procedures and results to ensure compliance with reporting obligations

In particular, the EU Emissions Trading Regulation (EUEMVO) distinguishes between Type 1 and Type 2 inspections. Type 1 locates potential leaks, while Type 2 quantifies the leakage rate for emissions reporting.

   Optical methane detection from the air   
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Fig. 1 Methane inspections using drones

Airborne optical methane measurement ( Fig. 1 ) uses hyperspectral cameras or sniffer devices that operate via tunable diode laser absorption spectroscopy (TDLAS). This method detects methane absorption signatures over large areas. By superimposing spectral and concentration data with geographic information, emission sources can be identified across distribution and transport networks.

This also allows methane concentrations in the atmosphere to be quantified, enabling leakage rates to be estimated using dispersion models.

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Fig. 2 Localizing emission hotspots during drone-based methane measurement

Case study

During a field campaign, a compressor station was surveyed by air. By correcting the methane concentration data for atmospheric effects – particularly by incorporating wind measurements – emission hotspots were located ( Fig. 2 ). This revealed that even small emission sources were detected that had not been identified during previous conventional inspections.

Advantages

  • Large-area coverage in a short time

  • Objective, measurable data for quantitative evaluation

Deployment scenarios

  • Periodic network overflights to identify previously unknown leaks

  • Validation of model assumptions for leak distribution

Deployment scenarios

  • Periodic network overflights to identify previously unknown leaks

  • Validation of model assumptions for leak distribution

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Fig. 3 Portable methane detectors can detect even the smallest methane concentrations using laser spectroscopy (TDLAS).

   Portable methane measurement in the field   

Portable, optically based sensors enable field personnel to identify leaks directly on site

( Fig. 3 ). The devices operate on the TDLAS principle and detect methane concentrations in the ambient air.

Application areas

  • Routine inspections along pipes and components

  • Verification of leaks located by other methods

  • Supplementary data for assessing leak severity near components

Features

  • Direct concentration measurement (ppm; parts per million) in real time

  • robust design for daily use

  • Integration with digital logging workflows

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Fig. 4 Example of an autonomous stationary methane measuring device including wind measurement 

   Stationary methane monitoring   

Stationary sensors complement mobile and point-source measurement methods by continuously acquiring data at critical points in the network ( Fig. 4 ). Integrated software solutions enable the following:

  • Creating time series of concentration measurements

  • Alarm triggered when defined limits are exceeded

  • Generation of basic data for statistical evaluations and trend analyses

  • Localization and quantification of measured emissions using wind measurements and wind dispersion models

Benefits in operational processes

  • Immediate detection of sudden increases in concentration

  • long-term observation of emissions trends and seasonality

  • Data basis for type 2 inspections for quantitative assessment

Fig. 5 Emission quantification at a ball valve using high-flow sampling | Fig. 6 High Flow Sampling in larger systems, eg gas pressure regulating systems (GPRS)

   High Flow Sampling and Quantification   

High-flow sampling is an established standard method for accurately quantifying leak rates . It can be flexibly used in both smaller systems ( Fig. 5 ) and larger industrial plants such as gas pressure regulating stations ( Fig. 6 ). In this method, a controlled airflow is passed through a leak source to measure the mass of methane contained within it using gas analyzers.

Methodology

  • Positioning: The nozzle of the sampler is fixed above the leak source.

  • Intake: A defined volume of air is drawn through the nozzle.

  • Analysis: Continuous measurement of the methane concentration in the aspirated gas.

  • Calculation: The emission rate is calculated from the volume flow rate and concentration values.

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Fig. 7 When performing quantification measurements, it should be noted that methane can accumulate in dead spaces, leading to a high initial value.

In practice, the values ​​measured during quantification prove to be representative if a stable state is awaited before measurement. It is particularly important to consider that methane accumulates in dead spaces, which can initially cause significantly elevated concentrations. Quantification should therefore only be carried out after a stable measurement has been reached ( Fig. 7 ).

Case Study Quantification 1: Ball Valve

In a field test, a leak in a ball valve was investigated using a high-flow sampler ( Fig. 5 ). Continuous measurement over 30 minutes yielded an average leak rate of 1.8 kg/h. This quantitative data allowed the leak to be classified according to regulatory reporting categories and supported management in prioritizing repair decisions.

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Fig. 8 High Flow Sampling in larger systems, eg GPRS, Measurement A

Case Study Quantification 2: Gas Pressure Regulating System (GDRS)

In a controlled experiment, an artificial methane emission with a target concentration of 500 ppm was generated inside the enclosed GPRS building. Measurements of the emissions in the exhaust air stream of the enclosure revealed methane concentrations significantly lower than those found inside the building. For example, the reference measuring device in the center of the room indicated 500 ppm, while at the beginning of the measurement, only 145.34 ppm were recorded in the exhaust air stream ( Fig. 8 ).

This difference is due to the mixing of the methane-containing room air with incoming ambient air beneath the enclosure tarpaulin. Consequently, the actual methane concentration in the plant room is not fully captured by the extraction system. Nevertheless, significant deviations from the reference measurement occurred: The concentrations measured in the extraction air stream were approximately 71% lower at the beginning and approximately 77% lower at the end than the reference values ​​inside the room. These results illustrate that the methane concentrations detected in the extraction air stream only partially represent the actual concentration in the plant room. In practice, this "dilution effect" should be compensated for. This underscores why a true quantification measurement is essential and concentration measurements alone are insufficient.

   Discussion   

The combination of various measurement technologies – from airborne methane concentration monitoring and portable sensors to stationary monitoring and high-flow sampling – creates a robust framework for detecting and quantifying methane emissions. Particularly important is the addition of quantitative quantity determination to qualitative localization in order to meet the requirements of current regulatory frameworks such as OGMP 2.0 and EUMVO. Regulatory requirements demand not only the detection of emissions but also valid, verifiable figures on emission levels. The described methods provide the following data:

  • Reproducible measurement data

  • Basics for Type 2 inspections and detailed reports

  • Decision-making criteria for maintenance and mitigation measures

   Conclusions   

  • State-of-the-art measuring systems enable detailed identification and quantification of methane emissions in distribution networks.

  • The combination of geometrically different methods creates a multi-stage inspection and quantification system.

  • Quantitative results are necessary to meet current regulatory requirements and to provide valid support for emissions reports.

  • Methodological transparency, standardized protocols and data integration are key to successful implementation.

Published in Aqua & Gas

Switzerland's leading journal for the water and gas sectors, published by SVGW.

Abbreviations used:

TDLAS – Tunable Diode Laser Absorption Spectroscopy

OGMP – Oil and Gas Methane Partnership

EUMR – EU Methane Regulation

ppm – parts per million

GPRS – Gas Pressure Regulating Station

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