Research Digest 014

Christopher G. Nixon
Greenhouse Gas Scientist

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The Highwood Bulletin is our way of sharing what we learn. We publish regular updates on emissions management news, novel research, and special insights from our team of experts and our partners.

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With methane detection technology evolving rapidly, this edition of our research digest brings exciting advancements in AI-driven super-emitter detection, independent satellite validation, and regulatory challenges for methane-intensive industries. We highlight new research on deep learning applications for methane plume detection, improved life cycle assessments for LNG exports, and the latest efforts to reconcile top-down and bottom-up emission estimates. 

AI-Powered Methane Super-Emitter Detection: Advancing Satellite-Based Monitoring with Deep Transfer Learning

A deep transfer learning framework for detecting methane super-emitters in oil and gas fields using Sentinel-2 satellite data is introduced. The researchers develop a two-part methodology: (1) an adaptive artifact removal algorithm (LRAD) to minimize noise from surface and atmospheric interferences, and (2) a deep subdomain adaptation network (DSAN) for methane plume detection across different regions.

DSAN is shown to achieve superior accuracy in identifying methane emissions compared to conventional convolutional neural networks. The framework is tested on real-world data from the Algerian Hassi Messaoud oil field, revealing three previously unknown methane super-emitters linked to production and pipeline infrastructure. The authors highlight the potential of AI-assisted satellite monitoring to enhance large-scale methane detection and mitigation efforts​ here.

Zhao, S., Zhang, Y., Zhao, S., Wang, X., & Varon, D. J. (2024). A Data-Efficient Deep Transfer Learning Framework for Methane Super-Emitter Detection in Oil and Gas Fields Using Sentinel-2 Satellite. EGUsphere, 2024, 1-34.

 

Assessing GHGSat’s Methane Monitoring Performance: Independent Validation of Satellite-Detected Emissions

An independent evaluation of GHGSat’s methane emission detection capabilities is conducted, analyzing satellite data from 250 scenes across Canada to assess the accuracy, detection limits, and uncertainties of reported emissions. The researchers combine GHGSat’s findings with alternative software and plume modeling determine the satellite system’s reliability.

GHGSat’s reported performance are found to be generally consistent with this study, with detection limits as low as 100 kg/h under ideal conditions, but more typically around 180–240 kg/h. This study highlights limitations due to environmental factors (e.g., surface reflectivity, terrain roughness, and wind variability)  here.

McLinden, C. A., Griffin, D., Davis, Z., Hempel, C., Smith, J., Sioris, C., … & Malo, A. (2024). An independent evaluation of GHGSat methane emissions: Performance assessment. Journal of Geophysical Research: Atmospheres129(15), e2023JD039906.

 

The EU Methane Regulation: Challenges and Uncertainty for LNG Imports

The impact of the European Union’s Methane Regulation on Liquefied Natural Gas (LNG) imports is examined. In force August 2024, the regulation establishes monitoring, reporting, and verification (MRV) requirements, leak detection and repair obligations, and restrictions on routine venting and flaring, as well as import-related methane emission requirements for fossil fuels.

The authors highlight significant concerns for the LNG industry, including unclear rules that will be defined in future regulatory acts and ambiguous key provisions that complicate compliance. The uncertainty surrounding the regulation is expected to make contract negotiations more difficult, potentially affecting the security of gas supply within the EU. The article calls for clarification from the European Commission to ensure smooth implementation and prevent disruptions in LNG trade here.

Talus, K., Steck, G., & Atkin, J. (2024). EU Methane Regulation and its impact on LNG imports. The Journal of World Energy Law & Business, jwae022.

 

Gas Pathing Improves Greenhouse Gas Emission Estimates for U.S. LNG Exports

A gas pathing algorithm is presented to enhance the accuracy of life cycle assessments (LCAs) for greenhouse gas emissions from LNG exports. The researchers apply this novel methodology to 138 unique gas pathways supplying two U.S. liquefaction facilities, revealing that emissions can vary by nearly a factor of six.

Measurement-based emissions estimates for U.S. LNG exports to Europe are found to be 41–52% higher than conventional reference cases, reflecting previously underreported emissions. However, compared to earlier studies using regional or national non-empirical estimates, the new methodology suggests emissions are 20–28% lower. The authors emphasize the importance of integrating supply chain-specific data and direct measurement techniques​ here.

Roman-White, S. A., Mallikarjuna Prasanna, D., McCullagh, A., Ravikumar, A. P., Allen, D. T., Chivukula, K., … & George, F. C. (2024). Gas Pathing: Improved Greenhouse Gas Emission Estimates of Liquefied Natural Gas Exports through Enhanced Supply Chain Resolution. ACS Sustainable Chemistry & Engineering12(46), 16956-16966.

 

Comparing Methane Emission Estimates: Observation vs. Inventory-Based Approaches Across Eight Major Global Emitters

Methane emissions from eight major global emitters are assessed: the European Union, the United States, Brazil, China, India, Indonesia, Russia, and the Democratic Republic of the Congo—using both bottom-up and top-down approaches. The researchers compare national greenhouse gas inventories submitted under UNFCCC with independent observation-based estimates, including satellite data from TROPOMI, GOSAT, and NOAA. Differences in system boundaries and methodologies are highlighted. The authors emphasize the pressing need forreporting of uncertainties. The authors further recommend expanding observation-based approaches to complement national reporting here.

Petrescu, A. M. R., Peters, G. P., Engelen, R., Houweling, S., Brunner, D., Tsuruta, A., … & Worden, J. R. (2024). Comparison of observation-and inventory-based methane emissions for eight large global emitters. Earth System Science Data16(9), 4325-4350.

 

A Comprehensive Assessment of Methane Emissions from Canada’s Oil and Gas Sector: Key Findings and Research Gaps

Nearly a decade of methane emissions research across the entire Canadian O&G value chain is synthesized, from production to end use. By integrating multiscale measurements from over 30 previous studies, the authors aim to refine national emissions estimates and identify critical gaps in current methodologies. Total methane emissions from Canada’s O&G sector are estimated at 2,600 (2,100–3,700) kt for 2021.

This study highlights the importance of frequent, comprehensive measurements to validate national reporting and track emissions reductions, especially as Canada aims for a 75% reduction in O&G methane emissions by 2030. The authors emphasize the need for independent verification and expanded measurement efforts to improve accuracy here.

MacKay, K., Seymour, S. P., Li, H. Z., Zavala-Araiza, D., & Xie, D. (2024). A Comprehensive Integration and Synthesis of Methane Emissions from Canada’s Oil and Gas Value Chain. Environmental Science & Technology, 58(32), 14203-14213.

 

Resolving Methane Emission Discrepancies in Canada’s Oil and Gas Sector: A Hybrid Bottom-Up and Top-Down Approach

Discrepancies in Canada’s oil and gas methane inventories are investigated, where atmospheric measurements have historically estimated emissions to be 1.5 to 2 times higher than official inventory reports. By integrating low-altitude aerial survey data with continuous tower-based atmospheric measurements, the authors develop a hybrid bottom-up/top-down framework that improves methane emission estimates.

This study shows the gap between inventory-based and observation-based estimates has been reduced by 80%, bringing discrepancies down to just 10% for the 2010–2014 baseline. The study also reports a 27% decline in inverse modelled O&G methane emissions from Alberta and Saskatchewan between 2010 and 2022, aligning with Canada’s 2030 methane reduction targets. The authors emphasize the importance of ongoing atmospheric monitoring and independent verification to ensure the accuracy of emissions reporting and the effectiveness of regulatory policies​ here.

Chan, E., Vogel, F., Smyth, S., Barrigar, O., Ishizawa, M., Kim, J., … & Worthy, D. E. (2024). Hybrid bottom-up and top-down framework resolves discrepancies in Canada’s oil and gas methane inventories. Communications Earth & Environment5(1), 566.

 

Airborne Methane Mapping Reveals High-Emitting Point Sources in Major U.S. Oil and Gas Basins

Airborne remote sensing data from MethaneAIR is utilized to quantify high-emitting methane point sources across 13 major U.S. oil and gas basins from 2021 to 2023. Detailed facility-level attribution is provided for over 400 methane sources emitting more than 200 kg/h, with over 80% attributed to oil and gas sources. This study reports a total point source emission rate of 360 t/h in 2023. The authors emphasize the importance of detailed source attribution, which will be improved on due to the growth of satellite-based detection here.

Warren, J. D., Sargent, M., Williams, J. P., Omara, M., Miller, C. C., Roche, S., … & Gautam, R. (2024). Sectoral contributions of high-emitting methane point sources from major US onshore oil and gas producing basins using airborne measurements from MethaneAIR. EGUsphere2024, 1-22.

 

Enhancing Methane Emission Estimates in the Denver-Julesburg Basin with Measurement-Informed Inventories

A novel methodology is shown to improve methane emission estimates from oil and gas operations in Colorado’s Denver-Julesburg Basin. The authors integrate inventory and aerial methods using the Mechanistic Air Emissions Simulator, a tool designed to reconcile these discrepancies by incorporating site-specific failure events into inventory data. This study suggests that current methods likely underreport emissions to CDPHE by approximately 16%, which likely represents a lower bound as true emissions could be even higher. The authors highlight that O&G inventories fail to account for emissions from upset conditions here.

Santos, A., Mollel, W., Duggan, J., Hodshire, A., Vora, P., & Zimmerle, D. (2024). Using Measurement-Informed Inventory to Assess Emissions in the Denver-Julesburg Basin. (preprint)

 

Comparing Continuous Methane Monitoring Systems at Operating Oil and Gas Sites: Accuracy, Challenges, and Implications for Emission Reduction

Three different continuous methane monitoring systems (CMS) deployed across six active oil and gas sites in the Appalachian Basin are evaluated. The researchers compare CMS output against aerial methane measurements and site-level bottom-up inventories, investigating differences in detection, localization, and quantification.

Significant short-term discrepancies between CMS solutions in detecting and quantifying emissions are seen, but agreement over longer time scales is better. Differences in emission rate estimates are largely driven by quantification algorithms rather than sensor platform. Challenges experienced by capturing intermittent emissions are discussed, making longer-term aggregation necessary for reliable emissions reporting. The authors underscore the potential of CMS for methane mitigation but highlight limitations and challenges here.

Daniels, W., Kidd, S., Yang, S. L., Stokes, S., Ravikumar, A., & Hammerling, D. (2025). Intercomparison of three continuous monitoring systems on operating oil and gas sites.

 

Optimizing Continuous Methane Monitoring: A Sensor Placement Framework for Oil and Gas Sites

A data-driven framework for optimizing the placement of point-in-space continuous methane monitoring system (CMS) sensors at oil and gas sites is presented. The proposed method aims to maximize methane emission detection efficiency while accounting for site-specific constraints and sensor budgets. The framework consists of five steps: simulating emission scenarios, defining potential sensor locations, modeling methane dispersion, assessing detection capabilities, and placement optimization algorithms.

The approach is shown to improve accuracy and reliability compared to conventional methods. This study demonstrates the framework’s effectiveness through onsite case study at an operational oil and gas site. The authors conclude by highlighting their algorithm’s flexibility to be used in various other applications​ here.

Jia, M., Robert Sorensen, T., & Martina Hammerling, D. (2024). Optimizing Point-in-Space Continuous Monitoring System Sensor Placement on Oil and Gas Sites. ACS Sustainable Resource Management2(1), 72-81.

Christopher G. Nixon

Greenhouse Gas Scientist

The Highwood Bulletin is our way of sharing what we learn. We publish regular updates on emissions management news, novel research, and special insights from our team of experts and our partners.

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