COSL Announces Unaudited Operational Data for the First Half of 2007

During the year 2007, oil and gas exploration and development activities in offshore China have remained vibrant; resulting in supply of drilling rigs and related services fell short of demand. The drilling services of the Company have maintained strong momentum throughout the period. For the six months ended 30 June 2007, the average utilization rate for drilling rigs of COSL in terms of available days reached 100.

0%, remaining at the same level as the corresponding period last year. In terms of calendar days, the average utilization rate was 97.9%, representing an increase of 10.3% over the corresponding period of the previous year. In the first half of 2007, operating days for drilling rigs increased by 434 days or 19.

5% to 2,658 days over the corresponding period last year, whereas that for jack-up rigs increased by 350 days or 19.7% when compared with last year. The above changes were mainly attributable to the commencement of operation of the new 400-feet jack-up rig COSL941 in June last year, leading to an increase of operating days by 176 days.

Moreover, maintenance days for jack-up rigs decreased by 174 days during the period. The operating days of semi-submersibles increased by 84 days or 18.9% as compared to the previous year, as maintenance days of semi-submersibles dropped 84 days.

During the first half of 2007, COSL recorded the following operating datum of well services: the Company provided logging and directional drilling to 462 wells and 248 wells respectively, representing a year-on-year increase of 32.0% and 145.5%. The enlarged operation volume of directional drilling was mainly attributable to the operation of NH2 which was deployed to offshore China after completion of overseas operation and the operation of COSL 941 .

COSL offered cementing of 238 wells, a surge of 76.3%, which was mainly due to the Company s expansion to overseas market. Also, COSL provided well completion services and drilling fluids to 790 and 139 wells respectively, posting an increase of 20.4% and a decrease of 17.8% respectively. Despite the decreasing operation volume of drilling fluids services as compared with that of the previous year, income generated from the operation increased with higher service fees due to the introduction of advanced technology and new materials.

As at 30 June 2007, COSL operated 70 support vessels, of which the total number of operating days for COSL672 , the newly added AHTS vessels, amounted to 132 days in the second quarter. The marine support and transportation services fleet of the Company operated for a total of 11,925 days during the period, posting an increase of 293 days or 2.

5% over the corresponding period last year. In terms of available days, the average utilization rate increased by 1.1% to 99.5%, whereas the average utilization rate in terms of calendar day reached 94.3%, representing a decrease of 0.2% as compared to that of the same period last year.

COSL ( COSL , stock code: 2883) is the leading integrated oilfield services provider in the offshore China market. Its services cover each phase of offshore oil and gas exploration, development and production. Its four business segments are drilling services, well services, marine support and transportation services and geophysical services.

COSL has been listed on the Main Board of the Stock Exchange of Hong Kong Limited since November 20, 2002. Since March 26, 2004, COSL's stocks can be traded by means of Level I unlisted American Depositary Receipts at OTC (over-the-counter) market in the United States. The ticker symbol is CHOLY.