press release

Unocal, co-venturers outline 2003 capital spending plan to help reduce Thailand reliance on imported energy:

Unocal, co-venturers outline 2003 capital spending plan to help reduce Thailand reliance on imported energy

Bangkok, March 3, 2003 - Unocal Thailand, Ltd., and its co-venturers today said they expect to invest nearly US$300 million (12,600 million baht) on crude oil and natural gas projects in 2003 to support Thailand's drive to reduce imported energy.

"The Thai economy is strong, growing, and needs the continued expansion of domestic energy supplies and improvement in the efficient use of that energy," said Randy Howard, Unocal Thailand's president. "We will continue to invest heavily in Thailand in 2003 and import technology to reduce the Kingdom's reliance on imported energy supplies."

Howard said that Unocal Thailand is focused on three key areas in 2003: exploring for additional oil and gas resources in the Gulf of Thailand, supporting the efforts of PTT Exploration and Production Public Company Limited (PTTEP) to develop the Arthit gas field in the Navamindra Production Area, and expanding crude oil production.

In 2002, Unocal Thailand gathered additional seismic data to prepare for expanded exploration activities in 2003. About 140 development and delineation wells are planned in 2003 to define new areas for possible future development in their offshore concessions. Unocal Thailand's exploration efforts have continued to expand the large oil and gas resource potential of Thailand. Over the last decade, the extensive exploration effort has led to an increase from 6 trillion cubic feet (tcf) to over 14 tcf of resource potential to the Kingdom.

"Our capital investment over the last 10 years and continued application of technology has resulted in growing the clean-burning natural gas resources that fuel the Kingdom" Howard said.

Unocal Thailand is a partner (16%) with PTTEP in the Arthit gas field, in the Gulf of Thailand area between Thailand and Vietnam. Development plans are underway by PTTEP for the start of gas production in 2006 into PTT's third major gas pipeline to Rayong.

"The development of Arthit and the addition of the third gas pipeline are critical steps to providing Thailand with continued low-cost domestic natural gas," said Howard, "We are assisting our partner PTTEP and customer PTT to see that these important projects are developed."

Unocal Thailand continues to focus on ways to apply technology to increase crude oil production from its oil fields in the Gulf of Thailand. The crude oil is found in small accumulations which were previously uneconomic to produce. Application of new technology and the continued effort to find low-cost ways to develop the oil eventually led to the start-up of the Plamuk, Platong, Surat, and Yala oil fields in 2001.

"Our technical teams have been working hard at identifying ways to increase the oil production from these hard-to-produce fields", said Tara Tiradnakorn, vice president of operations. Currently, Unocal produces about 20,000 barrels per day (gross). In addition, Unocal Thailand will expand its efforts to support energy conservation and environmental management education in schools with its "Captain Unocal" public service program.

Unocal Thailand's co-venturers consist of Mitsui Oil Exploration Co., Ltd., PTT Exploration and Production Public Company Limited, and Amerada Hess Exploration (Thailand) Co., Ltd.

About Unocal

Unocal Thailand is a wholly owned subsidiary of Unocal Corporation, one of the world's leading independent natural gas and crude oil exploration and production companies. Unocal's principal oil and gas activities are in North America and Asia.

This news release contains certain forward-looking statements about capital expenditures, the timing and volume of expected production, and drilling activities. Ultimate recovery is a speculative estimate (including non-proved resource) based on engineering, geophysical, and geological studies and may include market risk. 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 amended 2001 Form 10-K/A and other reports filed with the U.S. Securities and Exchange Commission. Unocal undertakes no obligation to update the information in this news release. U.S. investors are urged to consider closely the disclosure in Unocal's amended 2001 Form 10-K/A (SEC File No. 1-8483). Copies of the Unocal's SEC filings are available from the company by calling 800-252-2233. The reports are also available on the Unocal web site, www.unocal.com. You can also obtain this form from the SEC by calling 800-SEC-0330.

Updated: March 2003