Test Bed for Fugitive Methane Emissions Sensors (23.RP1.0186) – Completed

The challenge

While the energy industry accounts for approximately 22% of global methane emissions, it has been assessed by the IEA as having 56% of the abatement potential. Fugitive emissions of methane therefore represent a significant environmental and regulatory concern for Australia’s energy exports industry. This is particularly the case considering both specific frameworks for national reporting of emissions, (the NGER) and voluntary international disclosures (OGMP 2.0), as well as LNG methane intensity requirements associated with initiatives such as CLEAN and the European Methane Regulations. To maintain and enhance their reputation as reliable and responsible export partners, Australian energy exporters have shown great interest in reducing their fugitive methane emissions. The first step in being able to do this, is to be able to locate and quantify leak points. This is typically the purview of Leak Detection and Repair campaigns. To be able to conduct such a campaign, operators must both have access to LDAR technologies, and understand their performance characteristics. There are numerous vendors in the market with a variety of detection methodologies available; the natural question becomes: which of their claims can be trusted? This project set out to perform an independent test of four such LDAR systems: two high flow samplers, and two quantitative optical gas imaging cameras.

The objective and outcomes

The project can be conceptualised in three primary phases covering (1) inception, (2) measurement, and (3) application.

In Phase I, The University of Western Australia partnered with Woodside to develop a set of laboratory and outdoor facilities such that these pieces of equipment could adequately be tested. The basic structure of the testing scheme is to release a known quantity of methane using a high precision mass flow controller, and check the quantification of each piece of equipment against this benchmark. In this phase a laboratory system with release rates up to 5 slpm methane was developed, including a water bath able to provide background temperatures from 0 – 60°C  (necessary to provide a contrast for QOGI measurements). The outdoor system, located at UWA’s Shenton Park Campus is larger in scale, with the ability to release from three points through different flow meters at up to 10, 250 and 2000 slpm. The more complex outdoor environment allows for a better understanding of the effects of weather effects such as wind speed and direction – quantified with an anemometer during testing. Furthermore, the performance of the cameras at greater range and with variable backgrounds, for example clouds or trees, could be determined.

In Phase II, a set of leak rates between 0.4 and 7880 g/hr of methane were released and quantified by two high flow sampler technologies and two QOGI cameras: i) AddGlobe Gas Flow Meter 2.0; ii) Semtech Hi-Flow 2; iii) FLIR Gx620; iv) Konica Minolta GMP02. In broad terms, the high flow samplers provided a tighter range of measurements and showed lower deviations from expected release rate values than the cameras. Importantly, the specific uncertainties at a range of flow rates were identified, meaning that a leak reported by an LDAR team at a facility using one of these pieces of equipment can have a confidence interval assigned to it. This improves the overall quality of reported data, and will allow operators to build trust in their quantification initiatives. Generally, the uncertainty of high flow sampler measurements were closer to manufacturer claims in the mid-range of their claimed detection range, but deteriorated at the low- and high- ends. Further, valuable information on the practical operation of the QOGI cameras was gained.

Phase III consisted of a series of blind evaluations and training conducted for LDAR teams embarking on a measurement campaign. This process was important in the first instance because it removed operator bias in reporting measurement uncertainties. Secondly, it identified a useful workflow for a two-man LDAR team, where the cameras serve as an ideal tool for quickly identifying the location of leak points, enabling faster and more accurate measurement using the high flow samplers.

The impact

This project serves as a first step in building a fugitive emissions measurement and quantification capability for the Australian energy industry. Testing facilities at the laboratory and outdoor scales have been created, which are useful for both quantification of equipment performance, and as a familiarisation tool for LDAR crews before heading to site. The work suggests the need for further effort to develop and enlarge both the testing and training dimensions concurrently.

Next steps

In the first instance, FEnEx and partner organisations should seek to liaise with related global initiatives such as METEC and TADI to standardise testing procedures while expanding the complexity of the current test setup. This may include more complex release geometries, higher release rates and specific test protocols which can be applied both to LDAR systems and larger scale detection efforts such as drones or aircraft.