Marathon Successfully Appraises Droshky Discovery

Marathon Oil

Marathon Oil has successfully completed the appraisal of the previously announced Droshky discovery on Green Canyon Block 244 (OCS-G 11043) in the Gulf of Mexico, 137 miles south-southwest of Venice, La. Following the discovery well, the appraisal process consisted of drilling a downdip sidetrack well and a lateral sidetrack well.

The Droshky discovery is located in approximately 2,900 feet of water and is two miles south of the Troika Field Production System. The initial well was drilled to a total depth of 21,190 feet and encountered approximately 250 feet of net oil pay. The downdip appraisal sidetrack encountered more than 600 feet of net oil pay while the lateral sidetrack encountered approximately 300 feet of net oil pay. Preliminary analysis suggests that Droshky holds 30-32 degree API fluids, similar to the Troika Field. All pay intervals are Upper Miocene in age.

"The Droshky discovery is a good example of using higher quality seismic to see the value of a deeper opportunity adjacent to salt," said Philip G. Behrman, Marathon senior vice president of Worldwide Exploration.

Based upon the results of the three well penetrations, Marathon estimates the Droshky discovery holds mean recoverable resource of 80 to 90 million barrels of oil equivalent (gross). The Company expects to produce this field via subsea completions through the Troika system and Bullwinkle Platform, with terms already in place. The timing of initial production will be dependent upon delivery of key equipment (i.e. drilling rig and subsea equipment) and regulatory approvals, but could be as early as 2010.

Marathon holds a 100 percent working interest in the Droshky prospect and a 50 percent working interest in the Troika Unit.