COSL conforms to all international drilling industry standards and is duly certified by the pertinent global shipping societies. With the largest drilling fleet in Asia, and the third-largest drilling fleet worldwide, COSL operates and manages thirty-six jack-up rigs, twelve semi-submersible rigs and six modular rigs, all which are equipped with conventional and the latest cyber drilling systems, reliable power generators, mud circulation systems, and a full range of processing, cleaning, and environmental-protection equipments. 5000 feet semi-submersible rig HYSY982 will join the fleet by the end of 2017.

COSL has more than fifty years experience in offshore drilling including HTHP well operations, and can operate in water depth from 15 to 10, 000 ft, and drilling depth to 35 000 ft in a broad variety of environmental conditions. With successful operations and records in Offshore China, the Southeast Asia, Gulf of Mexico, the Middle East and Europe, COSL has earned high recognitions from customers.