Since its establishment in February 1982, China Offshore Oil Corporation has monopolized the development of offshore oil and gas resources in China, and is responsible for foreign cooperation and offshore oil technical services. In February, 20001,CNOOC spun off its core assets and listed in new york and Hongkong. After CNOOC went public, professional service companies and base logistics service enterprises became surviving enterprises. Cosl was born out of a surviving professional service company.