The Chunxiao natural gas field (known as Shirakaba gas field in Japanese) lies in the East China Sea within the Chinese Exclusive Economic Zone (EEZ) and only 4 km from the EEZ border claimed by Japan. The Chunxiao field is the first of a group of four natural gas fields in the Xihu Trough being developed by China: the other ones are Tianwaitian, Duanqiao, and Canxue.
Production from the field started on January 28, 2006.[1] CNOOC and Sinopec operate the site. Unocal and Shell withdrew from the project in late 2004 for reasons of high costs, unclear reserves, and the territorial dispute.
CNOOC estimates net reserves of the field at 31.6 billion BOE, of which oil comprises 3.8 billion barrels (600,000,000 m3) and the rest being natural gas (166.9 billion cubic feet (4.73×109 m3)).