press release

Unocal announces results of Ponza deepwater GOM well

Sugar Land, Texas, Aug. 22, 2001 -- Unocal Corporation (NYSE: UCL) today confirmed that it concluded drilling operations at its deepwater exploration well on the Ponza prospect in Keathley Canyon block 774 in the Gulf of Mexico in March 2001.

Although the well reached its objectives and penetrated hydrocarbon-bearing zones, the company said it does not appear to hold commercial quantities of pay. The well was plugged and abandoned; however evaluation of data from the Ponza well is continuing. Results were not disclosed sooner for competitive reasons related to today's OCS Lease Sale 180.

Under terms of farm-in agreements, Unocal incurred no net costs on the Ponza well. Unocal is the operator and holds a 50-percent working interest in Keathley Canyon block 774. Ocean Energy, Inc. (NYSE: OEI) holds a 25-percent working interest in the Ponza well. The remaining 25-percent working interest is held by another company, which was not named.

Unocal is currently operating an appraisal well at the Mad Dog prospect (Unocal, 15.6% working interest), a previously announced discovery located in Green Canyon block 826. The next deepwater well Unocal plans to drill is an appraisal well at the recently announced Trident discovery, drilled on Alaminos Canyon block 903. Unocal is operator of Trident and holds a 59.5-percent working interest in the seven-block discovery. Co-venturers include Chevron U.S.A. Production Company (NYSE: CHV), 15%; Ocean Energy, Inc. (NYSE: OEI), 12.75%; Agip Petroleum Co., the American subsidiary of Eni SpA (NYSE: E), 8.55 %; and Phillips Petroleum Inc. (NYSE: P), 4.2%.

About Unocal Corporation

Unocal is one of the world's leading independent natural gas and crude oil exploration and production companies. The company's principal operations are located in North America (Gulf of Mexico region, Alaska and Canada) and in Asia (Thailand, Myanmar, Indonesia, and Bangladesh). The company is also pursuing exploration programs in West Africa and Brazil.

This news release contains certain forward-looking statements about Unocal's dry hole expenses and future drilling plans. These statements are not guarantees of future performance. The statements are based upon Unocal's current expectations and beliefs and are subject to a number of known and unknown risks and uncertainties that could cause actual results to differ materially from those described in the forward looking statements. Actual results could differ materially as a result of factors discussed in Unocal's 1999 Form 10-K and subsequent reports filed with the Securities and Exchange Commission. Copies of the company's SEC filings are available from the company by calling 800-252-2233. The reports are also available on the Unocal web site.

Updated: August 2001