China Oilfield Services Limited, together with its subsidiaries, provides integrated oilfield services in China, Indonesia, Mexico, Norway, the Middle East, and internationally. The company operates through four divisions: Geophysical Services, Drilling Services, Well Services, and Marine and Transportation Services. It offers drilling services, including drilling lift boats and accommodation and rigs; well services, such as directional drilling, logging, drilling and completion fluids, cementing, workover, production and optimization, and well completion; and geophysics and geotechnical surveying, as well as marine support vessels comprising anchor handling, towing, cargo (passenger) transportation, stand-by, and oil lifting assisting services. The company was incorporated in 2001 and is based in Sanhe, China. China Oilfield Services Limited is a subsidiary of China National Offshore Oil Corporation.