Marathon Announces Natural Gas Discovery in New Area of Oklahoma

As part of the Company’s targeted expansion into key resource plays of North America, Marathon Oil Corporation announced that it has participated in a successful step-out discovery well on the Brickyard prospect, located in the northeast area of the Anadarko Basin, targeting the Woodford Shale resource play in Canadian County, Oklahoma.

The Cana No. 1-15H discovery well was drilled to a true vertical depth of 13,177 feet and horizontally for 4,090 feet, for a total measured well depth of 17,267 feet. The well flowed at an initial rate of 5.2 million cubic feet of gas per day. Marathon is the well operator and holds approximately 57 percent interest in the Cana No. 1-15H well. Other interest owners include Questar Corporation and Cimarex Energy.

“Marathon is encouraged by the results of the Brickyard prospect as we continue to develop the emerging Woodford Shale resource play,” stated Annell R. Bay, senior vice president, Worldwide Exploration. “We are using 3-D seismic technology to better define our targets and applying advanced drilling technology to reduce drilling days and well costs thereby improving overall well economics.”

Marathon holds approximately 30,000 net acres in the expanding Woodford Shale resource play with approximately 10,000 of those net acres in the immediate Brickyard prospect area. The Company is currently drilling two additional company-operated wells and is participating in two non-operated wells in the Brickyard prospect. Marathon also plans to participate in 15 to 25 gross wells in this area through 2010 with an anticipated 50 percent overall working interest. This limited program is designed to enhance the company’s technical understanding of the play and reflects the company’s focus on capital discipline. Marathon expects that with the successful development of this program, the play could yield an additional 200 to 300 gross locations.

The Cana well is believed to be the world’s first totally interventionless well completion using the patented EXcape Completion Process technology, developed jointly by Marathon, BJ Services, GEODynamics and the Expro Group. With EXcape, Marathon was able to remotely perforate, fracture stimulate and complete each individual interval zone for production, including the setting and removal of isolation devices — saving time and expense. Based on the success of the Cana well completion, Marathon plans to expand the use of this next-generation EXcape technology to future activities in its Oklahoma’s Woodford Shale and Alaska’s Cook Inlet operations.

“Compared to conventional completions using pump-down techniques in horizontal wells, the EXcape technology reduced man hours on this well completion by more than 35 percent and reduced completion costs by 10 percent,” Bay added.

For more information, visit the Company’s Web site at www.marathon.com.