The Efficacy of Methane Leak Detection and Repair (LDAR) Programs in Practice

Area of Science:

• Environmental Science
• Energy Policy
• Atmospheric Chemistry

Background:

• Methane emissions from the oil and gas sector are a significant concern.
• Leak Detection and Repair (LDAR) surveys are mandated by regulations.
• Assessing the real-world effectiveness of LDAR surveys has been challenging.

Purpose of the Study:

• To evaluate the effectiveness of optical gas imaging (OGI)-based LDAR surveys.
• To compare OGI-LDAR data with independent aerial survey data.
• To understand the limitations of current LDAR practices in capturing total methane emissions.

Main Methods:

• Analysis of three years of reported data from regulated LDAR surveys in British Columbia.
• Comparison with independent source-resolved aerial surveys at a subset of sites.
• Exclusion of potential combustion-related and intentional vent sources from aerial data for conservative comparison.

Main Results:

• 3x/year OGI-LDAR surveys reduced detected emissions by half at compliant sites.
• Aerial surveys detected 12 times more methane emissions overall compared to LDAR.
• Aerial surveys found 4 times more emissions even after excluding non-OGI targeted sources.

Conclusions:

• Regulated OGI-LDAR surveys capture only a small fraction of total methane emissions.
• Current LDAR practices may overestimate mitigation impacts.
• Complementary measurement approaches and independent verification (e.g., OGMP 2.0) are crucial for accurate emissions assessment.