Vastar Resources, Inc has successfully completed appraisal drilling at the Horn Mountain oil field on Mississippi Canyon blocks 126 and 127 in the Gulf of Mexico deepwater area. The results indicate that recoverable reserve estimates exceed commercial thresholds. Conceptual engineering studies necessary for developing the field have begun. Vastar holds a two-thirds working interest in the Horn Mountain field and serves as operator, with Occidental Petroleum Corporation holding a one-third interest. "The appraisal drilling program confirmed that the Horn Mountain field's extent and geology are as we expected. Thus, we are still comfortable with our pre-drill estimates that the field contains approximately 125 million barrels of recoverable reserves," said Philip Behrman, Vastar's Deepwater Exploration manager. "We are now proceeding with reservoir engineering work and studies of development options, and are excited about moving Horn Mountain toward eventual production." Several records were set during the drilling program. One well reached its total measured depth of 13,762 feet in only 12 days, an area record. World records were set for using a catenary rig mooring system in waters up to 6,023 feet deep, and for spudding a deepwater well only 13 hours after a rig relocation. Vastar expects to spud its next deepwater exploratory well by mid-December on the Anvil prospect on Mississippi Canyon block 815. The prospect lies in 5,400 feet of water about 80 miles southeast of Venice, Louisiana. Vastar serves as operator with 60 percent working interest. Since beginning its deepwater drilling program in late 1997, Vastar has achieved three discoveries. The first, on the King prospect, is expected to initiate production during the first half of 2000 from a subsea completion tied back to the nearby Mars platform. The second discovery was on the Mirage prospect, where future appraisal drilling is planned. The third was the Horn Mountain discovery. Vastar plans to drill or participate in four to six deepwater wells annually.