IEA (2020), "Methane Tracker 2020", IEA, Paris https://www.iea.org/reports/methane-tracker-2020
Our analysis examines emissions sources along the full oil and natural gas value chains, except for any emissions that occur within industrial or residential buildings (on the basis that the abatement technologies and options for these end-use emissions are materially different than those for the value chain up to the end-use consumer).
For simplicity, the oil and gas sectors are divided into upstream and downstream segments. Upstream includes all emissions from production and gathering and processing; downstream includes emissions from refining, transmission and distribution.
The production subsector includes all onshore and offshore oil and gas facilities from either conventional or unconventional reservoirs. Liquefaction of natural gas, transportation either by pipeline or as liquefied natural gas (LNG) and regasification are included in downstream processes.
- Fugitive methane emissions occur from leakages that are not intended, for example because of a faulty seal or leaking valve.
- Vented methane emissions are the result of intentional releases, often for safety reasons, due to the design of the facility or equipment (e.g. pneumatic controllers) or operational requirements (e.g. venting a pipeline for inspection and maintenance).
- Incomplete flaring methane emissions can occur when natural gas that cannot be used or recovered economically is burned instead of being sold or vented. The vast majority of the natural gas is converted into CO2 and water, but some portion may not be combusted and is released as methane into the atmosphere.
The monetary value attached to captured methane is viewed from a global, societal perspective. Estimates of well-head prices are used in each country, with a credit obtained for selling the gas applied regardless of what contractual arrangements between different companies may be required to lead to this result.
Prices also assume that there are no domestic consumption subsidies as the gas could be sold on the international market at a greater price. The well-head gas prices used could therefore be substantially different from subsidised domestic gas prices.