Chuanxi gas field in the Sichuan Basin, developed by China Petroleum and Chemical Corp (Sinopec), has completed construction and launched full production, with an annual capacity of 2 billion cubic meters of natural gas and 130,000 metric tons of sulfur, said the company.

Guo Tonglou, executive director and Party chief of Sinopec's Southwest Petroleum Bureau, said the gas field, with proven natural gas reserves of more than 100 billion cubic meters, is the third large-scale gas field of its type discovered by Sinopec in the basin, after Puguang and Yuanba gas fields.

"Scientific and technological innovation has played a leading role in the development of the gas field. Its full completion and operation have provided a successful experience for the scale-efficient development of ultra-deep oil and gas resources," Guo said.

The main gas reservoir of the western Sichuan gas field is buried at an average depth of about 6,000 meters, where geological conditions are quite complex, making it extremely difficult to develop in a cost-effective manner, said Lei Wei, director of the bureau's engineering technology research institute.

Lei said the bureau has independently developed a series of leading technologies and techniques for the drilling and construction of ultra-deep and long-horizontal wells, which have significantly improved the productivity and utilization of reserves for each well.

Pengzhou 5-1D well, the deepest of its kind in the western Sichuan gas field, has a depth of 8,208 meters and a horizontal length of 1,893 meters. Its daily output has reached 600,000 cubic meters, Lei said.

Li Huachang, production and operations management manager of Sinopec Southwest Oil and Gas Co, said the field has 16 wells, with daily output exceeding 6 million cubic meters when operating at full capacity — equivalent to the daily gas demand of about 12 million households.

Cai Suode, chief expert at Sinopec Southwest Oil and Gas Co, said the gas field has achieved a total sulfur recovery rate of over 99.9 percent by integrating advanced gas extraction and desulfurization technologies.

"The gas can meet national first-class standards and there is no wastewater discharge," Cai said.

The gas field has also established an intelligent operation and maintenance management platform to ensure safe and environmentally friendly processes throughout the entire operation and reduce carbon emissions, he added.

Sinopec has so far discovered proven reserves of nearly 3 trillion cubic meters of natural gas in the Sichuan Basin, with an annual production capacity of 26 billion cubic meters and a cumulative production of more than 200 billion cubic meters, the company said.

Zhang Chunqi contributed to this story.