Construction of the largest offshore natural gas field in the Bohai Bay area started on Saturday.

The Bozhong 19-6 Condensate Gas Field is expected to generate more than 100 billion cubic meters of gas, enough to supply a city of 1 million people for up to 100 years.

The field, discovered in 2019, has a proven natural gas reserve of nearly 200 billion cu m, according to a news release from CNOOC Offshore Oil Drilling Co, which launched the project.

The first phase is in Qingdao, Shandong province, and Tianjin.

A central operating platform, three drills and four pipeline frameworks are expected to be set up during the first phase, involving 32,000 tons of steel, equivalent to the weight of a midsize aircraft carrier. Eight underwater pipelines and three underwater cables will be laid, with a total length of 150 kilometers, said Ju Wenjie, the project manager.

CNOOC said it launched an experimental project soon after the discovery of the large gas field. That project entered service in October 2020, with daily peak natural gas output up to 1 million cu m.

"The success of the experimental project gave us confidence in the new project. We expect to make further breakthroughs in oil drilling technology," said Hao Baoqi, vice-general manager of the construction center under the drilling company, which is based in the Tianjin Port Free Trade Zone.

The first phase of the project is expected to begin drilling in November to provide clean energy for the Beijing-Tianjin-Hebei region and the Bohai Bay area, Hao said.