COMAT Methodology

The CoMAT Methodology guide details how the tool calculates methane emissions using a bottom-up equipment-based inventory combined with specific top-down measurements. It outlines the data inputs, emission factors, and abatement strategies for various oil and gas industry segments, including exploration, production, processing, transmission, storage, LNG, and distribution. The tool leverages defaults primarily from the US GHG Inventory (US GHGI) while allowing for country-specific updates to refine emissions inventories and design policy strategies.

• CoMAT calculates methane emissions using a general formula: Methane emissions = Industry Contributor * Activity Driver(s) * Emission Factor, or more simply, Activity Data (AD) * Emission Factor (EF).
• The tool primarily derives its default activity data and emission factors from the US GHG Inventory (US GHGI), using a pre-regulatory baseline based on 2011 data for new/modified sources.
• CoMAT incorporates top-down measurement data for specific sources: it uses NOAA satellite data for associated gas venting and flaring, and a factor based on Alvarez 2018 to estimate emissions from abnormal process conditions.
• The methodology identifies 'super-emitters'—large but uncommon emissions caused by improper operations like stuck valves or open hatches—as a major source of leaks that are unpredictable and can occur at any site.
• For leak abatement, CoMAT uses a 'rule of thumb' based on inspection frequency: 40% reduction for annual, 60% for bi-annual, 70% for triannual, 80% for quarterly, and 90% for monthly inspections.
• The tool's 'Best Practice' policies target specific reduction goals across various sources, including a 95% reduction for centrifugal compressors, dehydrators, liquids unloading, pneumatic pumps, and reciprocating compressors.
• To mitigate pneumatic controller emissions, the methodology advocates for 'zero-bleed' devices—which use compressed air or electricity—over high- or low-bleed controllers, as low-bleed devices often malfunction and emit more than their threshold.
• Reduced Emissions Completions (REC) are identified as a highly effective measure for well completions and workovers, capable of reducing methane emissions by more than 95% for both oil and gas wells.

APA

Clean Air Task Force (2025). COMAT Methodology. https://cdn.catf.us/wp-content/uploads/2024/09/21114432/CoMAT_Methodology_V2.pdf

Chicago

Clean Air Task Force. COMAT Methodology. 2025. https://cdn.catf.us/wp-content/uploads/2024/09/21114432/CoMAT_Methodology_V2.pdf.

Wikipedia

{{cite report |author=Clean Air Task Force |title=COMAT Methodology |date=February 2025 |url=https://cdn.catf.us/wp-content/uploads/2024/09/21114432/CoMAT_Methodology_V2.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{cleanairtaskforce2025comat, author = {{Clean Air Task Force}}, title = {{COMAT Methodology}}, institution = {Clean Air Task Force}, year = {2025}, month = feb, url = {https://cdn.catf.us/wp-content/uploads/2024/09/21114432/CoMAT_Methodology_V2.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }