China's largest coalbed methane field, the Daji Gas Field in north China's Shanxi Province, has exceeded an annual production capacity of 4 billion cubic meters (bcm), becoming an important new contributor to the country's natural gas supply.

Coalbed methane is an unconventional natural gas resource that exists in adsorbed or free form within deep underground coal seams, typically buried more than 1,500 meters below the surface.

The Daji Gas Field is China's first demonstration project for coalbed methane development. Since the beginning of this year, 16 new wells have been drilled, and an additional annual capacity of 250 million cubic meters has been built.

The developments have pushed daily gas production beyond 11 million cubic meters, a year-on-year increase of 32%.

Compared with conventional natural gas, coalbed methane resources are buried deeper and involve more complex geological conditions, making extraction technically challenging. For years, such deep layers were considered a "forbidden zone" for oil and gas exploration.

In 2019, China National Petroleum Corporation launched a technological breakthrough program that led to the first industrial gas flow from the Daji 3-7 well. In December 2021, the Jishen 6-7 well produced more than 100,000 cubic meters per day, marking a major milestone in efficient coalbed methane development.

With an average burial depth of about 2,130 meters and proven geological reserves of 400 billion cubic meters, the Daji Gas Field is China's first large-scale coalbed methane field. It now accounts for more than 80% of the country's total coalbed methane output.