China Oilfield Services Limited

Drilling Services

Marine Support & Transportation Services

Drilling Services

COSL is the major provider of drilling services in offshore China which also engages in drilling services around the world. We have over 30 years experience in oilfield services since we performed our first offshore drilling in 1967. We undertake to our customers to provide safe, quality and efficient services. COSL currently operate 16 drilling rigs, including 12 jack-ups and 3 semi-submersibles, and leased 1 jack-up. The rigs are accredited with ABS, DNV and CCS classifications, processing operating water depth range of 5-457 m and maximum rated drilling depth of 9,000 m. The construction of COSL 941, a jack-up rig up to international standards with maximum operating water depth of 400 ft (122 m) and maximum rated drilling depth of 30,000 ft (9,144 m), was completed and commence operation in 2006. COSL 941 equipped with the drilling capability to operate in high temperature and high pressure well condition.

Rig Services

COSL operates 16 offshore drilling platforms, including 13 jack-up rigs and 3 semi-submersibles rigs. Through its capability of drilling in a wide range of wells with various depths, our fleet of drilling rigs is able to meet the demand for drilling services in offshore China. We spare endless efforts in modifying and upgrading our drilling rigs in order to achieve technological advancement and to cater for the growing demand.

All of our drilling rigs are well maintained. We also endeavor to modify and upgrade our rigs so as to support the latest innovative drilling technologies and equipments. We have installed the sophisticate drilling drive system to all of our rigs, which enable them to drill with the over 90-feet long drill pipes instead of the limiting 30- feet standard. This advanced drilling drive system allows the drill pipe to rotate constantly while entering or exiting a well, which largely enhanced the drilling speed, personnel safety and drilling efficiency. At the same time, it significantly reduces the risk of drill string sticking incidents during operations. We have also modified two of our rigs to drill in high temperature and high pressure well conditions. Currently, our rig fleet is capable of drilling in wells with depth ranging from 20 to 1,500 ft which is fully equipped for drilling in all conditions typically found at offshore China.

We pay strong emphasis on equipment upgrade and maintenance and we build new facilities promptly in response to market demand. COSL’s first self-built 400-feet jack-up rig COSL941, also the first in PRC, was delivered in May 2006 and currently operates smoothly in Beibu Gulf, South China Sea. It largely strengthened our international competitiveness in drilling. Also, our second 400-feet jack-up rig COSL942 is under construction and expected to be ready for operation in the first half of 2008. We have started to build two 350-ft jack-up rigs, COSL935 and COSL936, purchase a series of equipments and gradually launch upgrade and modification projects. Besides, CNOOC will also commence construction of China’s first deepwater rig.

Liftboat services

COSL proactively seeks for increasing client’s oil yielding rates, expanding the areas of cooperation between the Company and clients. The provision of liftboat services reflects COSL’s efforts in strengthening production capability of oilfield services. In December 2006, we signed the construction agreements for two liftboats. The operation of the liftboats will make a difference in the operation mode of oilfield exploration.

Module rig services

In 2006, COSL unprecedentedly extended its module rig services to a mature oil extraction market, Gulf of Mexico. It obtained a contract to construct 4 module rigs and lease them for operation as long as three years. COSL was responsible for the investment and construction of the four module rigs, and the mobilization, installation and rig-up. The project will be delivered in the 2nd quarter of 2007. Currently, module rig COSL4 has completed platform installation stage at the location requested by clients. The project fully reflected the world class management ability of COSL and thus laid a solid foundation for COSL’s exploration of new profit driver.

Rig management services

COSL is capable of providing rig management services. COSL engaged in the management of the Semi-submersibles for Iran's North Drilling Company (NDC) in January 2006, successfully extending its rig management services to rigs owned by others.

Well workover services

COSL owns a number of well workover rigs to provide well workover services for clients. In recent years, our well workover services have achieved greater development. Team day in 2006 reached 13.369, posting a growth of 57.6% as compared with the corresponding period in 2005.

Key specifications of our jackup rigs: