Conoco and Partners Complete Drilling of Successful Appraisal Well in Vietnam Block 15-1.

Business/Energy Editors

HOUSTON--(BUSINESS WIRE)--May 22, 2001

Conoco (NYSE:COCA) (NYSE:COCB) and its partners have completed drilling of a successful appraisal well, Sutu Den-2X, in Block 15-1 offshore Vietnam, which they believe further supports the commercial viability of the Sutu Den, or Black Lion, prospect. This is the second significant drilling success in Vietnam the company has announced within a month.

The combined flow rate of Sutu Den-2X is 11,032 barrels of oil per day (bopd). This rate is based on combined well tests from two major pay zones in the fractured basement and Miocene reservoirs. The oil gravity (API) is between 34 and 36 degrees for the reservoirs. Currently, Conoco and its partners are evaluating the well results to assess reserve potential.

Located in the Cuu Long Basin, 120 miles (180 kilometers) southeast of Ho Chi Minh City, the Sutu Den prospect is on the far east side of Block 15-1 in 154 feet of water (47 meters). The well is located approximately 1.6 miles (2.7 kilometers) from Sutu Den-1X, the discovery well announced in September 2000. The Sutu Den-1X well flowed more than 12,600 bopd from three zones, and is estimated to have an additional 5,200 bopd untested potential from three other zones.

"We're encouraged by the continued success of Block 15-1, and feel the Sutu Den prospect has the potential to be significant in size," said Rob McKee, Conoco executive vice president, worldwide exploration and production. "Results to date support the commercial viability of the field, so the plan is to accelerate development to bring the field to production as soon as possible."

Conoco holds a 23.25-percent interest in Block 15-1, which covers 1.15 million acres (4,634 square kilometers) and is near the producing Bach Ho, Ruby and Rang Dong fields. Other partners are PetroVietnam (50 percent), Korean National Oil Corporation (14.25 percent), SK Corp (9 percent) and Geopetrol (3.5 percent).

Conoco also holds a 36-percent interest in Block 15-2, which is adjacent to Block 15-1 and currently producing 55,000 bopd from the Rang Dong field. The increased flow rate of well 15P in Block 15-2 represented a new production milestone, which Conoco announced in April.

The company also holds a 40-percent interest in Block 16-2 and plans to drill the first exploration well later this year. Conoco will serve as operator for Block 16-2's exploration, development and first production phases.

In addition, Conoco is operator and holds a 70-percent interest in the Vietnam deepwater Blocks 133 and 134.

Conoco is a major, integrated energy company active in more than 40 countries.

This release contains forward-looking statements about Conoco's business plans and operations. These statements are not guarantees of future performance, involve certain risks, uncertainties, and assumptions that are difficult to predict, and are based upon assumptions as to future events that may not prove accurate. Actual outcomes and results may differ materially. Among the factors that could cause such differences are changes in oil and gas prices; unsuccessful exploration and development drilling activities; failure to achieve expected reserve or production levels due to operating hazards, drilling risks, and the inherent uncertainties in interpreting engineering data relating to underground accumulations of oil and gas, inability to obtain government approvals for project development; interruption of operations due to accidents or political events, as well as other risks discussed in Conoco's publicly available filings with the Securities and Exchange Commission.