On March 5, China’s largest coal-rock gas field, PetroChina’s Daji Gas Field, saw its annual production capacity exceed 4 billion cubic meters. The field now accounts for more than three-quarters of the country’s total coal-rock gas output, becoming an important replacement resource for China’s growing natural gas production.

Coal-rock gas is an unconventional natural gas resource adsorbed or free within deep underground coal seams, usually buried at depths greater than 1,500 meters, with broad prospects for exploration and development. China’s first coal-rock gas demonstration project, the Daji Gas Field, is located in southwestern Shanxi Province. Since the beginning of this year, PetroChina Coalbed Methane Company has drilled 16 new wells and added 250 million cubic meters of new production capacity, pushing daily gas output at the field to over 11 million cubic meters, up 32% year on year.

From 2023 to 2025, the Daji Gas Field achieved rapid stepwise growth in coal-rock gas production within just three years, continuing to lead the development of China’s coal-rock gas industry. Since gas supply for the winter heating season began last year, the field has produced a cumulative 1.05 billion cubic meters of natural gas, setting a new historical record.

Compared with conventional natural gas, coal-rock gas is buried deeper and occurs under more complex geological conditions, making it technically challenging to develop and long regarded as a “deep forbidden zone” in oil and gas exploration. In 2019, PetroChina began technical breakthroughs in this field, and the first coal-rock gas well, Daji 3-7, achieved industrial gas flow. In December 2021, the Jishen 6-7 well produced more than 100,000 cubic meters of gas per day, becoming China’s first “breakthrough well” for efficient coal-rock gas development.

In recent years, PetroChina Coalbed Methane Company has continued to advance theoretical innovation in coal-rock gas exploration and development, establishing a theoretical framework for coal-rock gas enrichment and precisely revealing the dual-phase occurrence pattern of “adsorbed and free gas” in deep coal strata. Driven by technological innovation, the company has accelerated efficient development of coal-rock gas by developing several key technologies, including “geology-engineering integrated steering” and “3,000-meter ultra-long horizontal sections,” strongly supporting large-scale commercial production. Currently, the company is steadily advancing the Phase II capacity expansion project of the Daji Gas Field. Once completed, it will add an annual production capacity of 1.5 billion cubic meters, injecting strong momentum into China’s energy security.