[1] It also has a listed sister company in Hong Kong, CNOOC Limited.

China Oilfield Services usually purchases off shore vessels (OSVs) and operates them in Southeast Asia, the Middle East and Central Asia in off shore projects of CNOOC.

COSL had an office in Kuala Lumpur, Malaysia briefly in the early 2000s when it had its first western Vice President, Alan Good, a British born Oilman who helped launch the company internationally and pushed for further growth in the international sector.

Globally, the number of listed players in the oilfield services sector is just over 100, with a combined market capitalisation of about US$250 billion.

Globally, about 15% of oil companies' capital expenditure goes to exploration, 35% to field development and 50% to production.