Mariner's West Texas Acquisition Ups Proved Reserves by 14 Bcfe

Mariner Energy, Inc. has closed on the acquisition of an additional 5% working interest in the Mariner-operated Spraberry Aldwell Unit in the Permian Basin for approximately $21.7 million. Mariner estimates net proved oil and gas reserves attributable to the interests of approximately 14.0 Bcfe (65% oil and liquids).

Current production from the property is approximately 1600 Mcfe per day. The interest was acquired from Plains Exploration & Production Company through Mariner's exercise of a preferential right to purchase in connection with Plains Exploration & Production Company's transaction with Oxy USA Inc. dated December 14, 2007.