ATP Marks Two Deepwater Exploration Discoveries

ATP Oil & Gas Corporation recently participated in the drilling of two successful exploration wells in the deepwater Gulf of Mexico. The Gladden Prospect, located at Mississippi Canyon 800 in approximately 3,116-foot of water, found 80 feet of net oil pay.

An updip location is being drilled that is expected to be completed in late May. The Anduin West Prospect, located at Mississippi Canyon 754 in approximately 2,696-foot of water, found 30 feet of net gas and condensate pay. The Anduin West well is being completed and a production test is planned for next week. ATP has a 10% working interest in Gladden and a 25 % working interest in Anduin West. Newfield Exploration Company is the operator of both discoveries.

ATP has production handling agreements in place for its ATP Innovator moored at Mississippi Canyon 711 "Gomez" to process the oil and gas from both locations, and production is expected to begin in late 2009.

T. Paul Bulmahn, ATP's Chairman and President said, "The future production and reserves associated with these discoveries are not included in our current reserve report. These properties also provide committed third party production to be processed for a fee by our ATP Innovator, enhancing the value of that asset. Clearly, these two discoveries validate our deepwater Hub concept, and we presently plan to drill three future wells at the Gomez Hub."