To achieve its carbon peaking and carbon neutrality objectives, China is committed to promoting a decarbonized energy transition, which has strengthened the shift from coal to oil and gas resources. As a result, methane (CH4) fugitive emissions from China's oil and gas systems are of increasing concern. Fugitive emissions include equipment leaks, venting, and flaring and involve exploration, production, transportation, storage, and distribution of oil and gas resources. However, there is no uniform accounting method for methane fugitive emissions from oil and gas systems, and fugitive emissions have not been included in the national greenhouse gas inventory statistics. Using the relevant methods, methane fugitive emissions from China's oil and gas systems were estimated for the period from 1980-2020. The results showed that CH4 fugitive emissions from oil and gas systems increased rapidly with the growth of production and consumption of oil and gas resources, from less than 0.6 million tons in 1980 to more than 2.6 million tons in 2020. CH4 fugitive emissions from oil and gas systems reached approximately 0.6 million tons and 2.0 million tons, which were 1.38 and 16.6 times larger than those in 1980, respectively. Fugitive emissions from oil and gas systems originated primarily from gas production, oil production, gas transportation, and storage, accounting for 41%, 20%, 18%, and 13% of total emissions, respectively. Gas pipelines were the main fugitive facilities. The emission intensity of unconventional oil and gas resource exploration was higher compared to conventional resource exploration. This study improved the CH4 fugitive emission inventory, which could provide solid scientific data for CH4 reduction.
Keywords: climate change; fugitive emissions; methane emission inventory; methane emissions; oil and gas system.