Consistent with our Methane Guiding Principles commitments, APA is continuing to explore advanced methane measurement and leak detection approaches. Our FY24 actions built on previous work in FY23 that included a ground level methane leak survey on GGP and high spatial resolution aircraft monitoring of the GGP, MSP and SWQP (refer to the Climate Report 2023).
In FY24 this work focused on enhanced methane measurement on the South West Queensland Pipeline (SWQP), trialling alternative aerial detection technologies and informing our gas infrastructure emissions reduction roadmap. We selected the SWQP due to it being a major gas transmission pipeline with a total of 16 compression units located along the pipeline, including hubs at Wallumbilla and Moomba and covered under the Safeguard Mechanism.
We completed direct source-level measurements and engineering calculations across the SWQP.1 These measurements were then reconciled with independent measurements from an aerial survey conducted by Bridger Photonics by helicopter using gas mapping Light Detection and Ranging (LiDAR) technology. This technology targets measured methane emissions to a sensitivity of 0.5 kg/hour with 90% probability.
Our focus for the work was on assessing emissions from fugitive methane sources2, incomplete combustion3 and venting4 sources to support our planned methane abatement actions. The methodology applied to complete this work was consistent with the methodology that would be applied under the Oil and Gas Methane Partnership 2.0 (OGMP 2.0) reporting framework.
The measurement work confirmed there were no emission sources detected from APA’s two parallel pipelines and those emission sources that were identified are already the focus of our emissions reduction plans.
More detailed findings from the SWQP enhanced methane measurement work were as follows:
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no emission sources were detected from the twoparallel pipelines, a total pipeline length of 1,874 km
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all emissions were from pipeline infrastructure sites along the SWQP – compressor stations, scraper and main line valve stations
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no methane fugitive leaks of process safety concern were identified
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fugitive methane emissions were comparatively low, with methane detected at about 1.4% of the approximately 20,000 potential sources. About 40 leaks that could be repaired immediately were addressed during the measurement campaign, with remaining leaks scheduled to be addressed in accordance with APA’s Leak Management Protocol
1 Incomplete combustion emissions were based on engineering calculations rather than direct measurements.
2 Fugitive emissions related to the unintentional release of methane.
3 Incomplete combustion of methane occurs in fuel-burning equipment where not all methane is converted to CO2, resulting in methane slip being released into the atmosphere.
4 The main sources of vented emissions include compressor blowdowns, compressor seals and gas driven pneumatic equipment (e.g. high-bleed valves).