Methane emissions from oil and gas production sites in Alberta, Canada

Abstract

We performed ground-based measurements (downwind, site-wide characterization) of methane emissions from older light oil and natural gas production sites in Alberta, Canada (Red Deer region, 60 measured sites). We developed a distribution of site-based methane emissions and as previously found in production regions in the United States, a small fraction of the sites account for the majority of methane emissions: 20% of the sites emit three quarters of the methane from oil and gas production. Using empirically derived emission factors, we compared an estimate of regional methane emissions, to a top-down airborne-based measurement of the same region. The airborne measurement was 35% lower, though not statistically different (4,800 ± 3,200 vs. 3,100 ± 2,200 kg CH4 h–1). In Alberta, the majority of these oil and gas emissions go unreported under current reporting requirements. Effective mitigation will most likely require frequent monitoring to identify high-emitting sites as well as leaky components that we hypothesize are also a major contributor to emissions.