Handbook for estimating methane emissions from Canadian natural gas systems

An overall framework by which companies in the natural gas industry can assess their methane emissions was described. A set of terms, source categories and nomenclature was established to allow for comparisons and easy aggregation of methane-emissions data for future industry reporting initiatives. This handbook deals only with methane emissions from non-combustion sources such as process venting and fugitive equipment leaks at gas transmission, storage and distribution facilities. The common assessment methods to estimate methane emissions for each applicable source type are summarized. Target source types include: (1) fugitive pipeline and equipment leaks, (2) emissions from third-party damage, (3) blowdown events, (4) purging activities, (5) still-column vents on glycol dehydrators, (6) compressor starts, (7) use of natural gas as the supply medium for gas-operated devices, and (8) venting by gas samples, analyzers, relief valves and regulators. The need for good quality assurance control measures to ensure reliable results is emphasized. 36 refs., 19 tabs., 7 figs., 1 appendix