Unocal Begins West Seno Development Drilling

Unocal's subsidiary, Unocal Makassar, Ltd. as a production-sharing contractor to BPMIGAS, commenced drilling operations on Phase One of its deepwater West Seno field offshore East Kalimantan, Indonesia.

The first well of a 28-well development program spudded from the Tension-Leg Platform, TLP-A, located in the Makassar Strait in approximately 3,200 feet of water.

This is a significant milestone towards first deepwater production for Unocal and Indonesia," said Brian W. G. Marcotte, president of Unocal Makassar, Ltd. "We have successfully installed the first TLP in Southeast Asia and will be drilling development wells prior to the arrival of our Floating Production Unit (FPU). All submarine pipelines, deepwater mooring systems, and onshore facilities are complete and awaiting the arrival of the FPU."

The FPU, designed to process 60,000 barrels of oil per day (BOPD) and 150 million cubic feet of natural gas per day (MMCFGPD), is currently undergoing final construction and yard commissioning in Ulsan, Korea. The unit will be towed to the field site in Indonesia in late April.

Offshore installation of the FPU to its pre-laid deepwater moorings and hookup to the TLP and export pipelines should be completed by mid-May. Offshore commissioning and startup activities will take another 30 days. The field is scheduled to come on production in mid-June 2003. Initial production of 12,000 to 15,000 BOPD is expected from the first five pre-drilled development wells. Production is expected to steadily increase to 35,000 to 40,000 BOPD by year-end 2003 and continue ramping up in 2004 as the remainder of the Phase One drilling program is executed.

Phase Two, which is expected to come on line about 2 years after Phase One production commences, will include a second TLP, infield pipelines and up to 24 additional development wells. Daily production is targeted to reach 60,000 barrels of oil and 150 MMCFG in 2005 following the second phase development. Ultimate recovery from the field is expected to be 210 to 320 million barrels-of-oil equivalent.

Unocal Makassar, Ltd., is operator of the Makassar Strait Production Sharing Contract (PSC) area. It holds a 90-percent working interest in the PSC, with Pertamina Upstream holding the remaining 10-percent working interest.