press release

Unocal sets drilling records in developing Funan gas field offshore Thailand

El Segundo, Calif., March 25, 1999 - Unocal Corporation today said its Unocal Thailand, Ltd., subsidiary set two records in drilling natural gas development wells at the Funan J platform in the Gulf of Thailand .

The company drilled the Funan J-13 well at a rate of 5,145 feet per day (FPD), believed to be a world record. This performance eclipsed the previous single-well Gulf of Thailand record of 4,720 FPD set in 1997 on the Satun A-17 well. The Funan J-13 well was drilled to 9,862 feet (7,900 feet vertical depth) in only 46 hours.

Each platform contains about 14 gas development (or production) wells. For the entire Funan J platform development, the average penetration rate of the 14-well drilling program was 4,010 FPD. This was 21 percent faster than the previous record of 3,300 FPD for all wells on the Satun L platform in 1997. The 14-well drilling program was completed in just 61 days.

"The records achieved on the Funan J platform make it the most efficiently drilled development so far for Unocal Thailand," said, Tara Tiradnakorn, Unocal Thailand's vice president of operations. "Continued focus on improving drilling and operating efficiency will ensure that we will be able to economically produce the maximum amount of clean-burning natural gas for Thailand. This will benefit both the Kingdom and Unocal by reducing the amount of imported fuels needed to drive the economy."

Tiradnakorn said the company achieved the two drilling records because of its familiarity with the behavior and characteristics of Gulf of Thailand geology and the application of slimhole drilling. Slimhole drilling, pioneered by Unocal in Indonesia, uses a smaller well diameter than conventional oil and gas wells to reduce drilling time and produce fewer well cuttings.

The 14 wells on the Funan J platform were drilled at an average cost of $800,000 per well, or $77.05 per foot. The J-13 well cost $636,000, or $64.50 per foot.

"These drilling records were also achieved safely, without any incidents," Tiradnakorn said. "We take great pride in our safety record, and we emphasize that safety and efficiency work hand in hand." Unocal has drilled approximately 1,200 wells in the Gulf of Thailand.

The Funan J platform is expected to produce about 46 billion cubic feet of natural gas equivalent. The platform will come on production May 1999 at a rate of 60 million cubic feet of gas per day.

Unocal Thailand is the leading producer of natural gas in Thailand. Together with it's co-concessionaires - Mitsui Oil Exploration Company Limited and PTT Exploration and Production Public Company Limited - Unocal is currently producing nearly 1 billion cubic feet of natural gas and 33,000 barrels of condensate per day. Unocal's average net working interest is 64 percent.

Unocal is one of the world's largest independent oil and gas exploration and production companies, with resource development, power plant and pipeline projects in Asia, the U.S. Gulf of Mexico region and Latin America.

Forward-looking statements regarding reserves and future production rates in this news release are based on assumptions concerning market, competitive, regulatory, environmental, operational and other considerations. Actual results could differ materially as a result of factors discussed in Unocal's 1998 Form 10-K report filed with the Securities and Exchange Commission.

Updated: March 1999