ATP Suspends Ops Temporarily Due to Moratorium

ATP O&G announced that the Mississippi Canyon (MC) 941 #3 well at its Telemark location can be completed and the current drilling operation at MC 305 #2 in the Canyon Express area will need to be temporarily suspended. Both announcements are in compliance with the May 30, 2010 6:52 pm CDT Notice to Lessees (NTL) from the Minerals Management Service (MMS) which imposed a six month moratorium on drilling operations in the deepwater Gulf of Mexico as a result of the BP oil spill. Additional clarity regarding the application of the NTL was gained from other pronouncements and releases during ensuing days.

Addressing this update, T. Paul Bulmahn, Founder, Chairman and CEO of ATP expressed, "The tragedy of loss of human life and damage to the environment when discussing the BP oil spill cannot be overstated. Everyone at ATP Oil & Gas Corporation would like to extend our deepest sympathy and continued prayers and support to both individuals and families who have been impacted by these events. As nothing compares to the tragedy of loss of life, we also ask that no one forget the estimated forty-five thousand workers and the families of those workers that will find themselves unemployed as a result of the imposed deepwater work stoppage."

Telemark Hub Update

ATP has begun the completion operations of the MC 941 #3 well which encountered 266' of net pay, triple the amount of net pay found in the original discovery well. The NTL provides for completion operations which will allow this well to be placed on production. Access to vendor equipment and services which are necessary for the completion of this well have been limited due to preferential utilization in the BP oil spill. ATP now expects to commence production at the MC 941 #3 during the third quarter 2010. The next two wells at the Telemark Hub, the MC 941 #4 and MC 942 #2, originally scheduled for the third quarter and fourth quarter of 2010, now need to be rescheduled to early 2011 according to the NTL. There is currently one well producing at the Telemark Hub.

ATP operates the deepwater Telemark Hub with a 100% working interest and owns 100% of the ATP Titan and associated pipelines and infrastructure.

Gomez Hub Update

Existing production at the Gomez Hub (MC 711/754/755), ATP’s single largest producing property in the Gulf of Mexico, is unaffected by the NTL. ATP continues to produce the Gomez Hub. The MC 754 #1 well which has been completed is not impacted by the NTL and will be brought on production late 2010 following a pipeline lay and connection. Later in 2010 and early 2011, two wells, the MC 711 #9 and MC 711 #10, were scheduled to be drilled. These development wells would be the ninth and tenth wells drilled into the development reservoirs at Gomez. These wells will now be rescheduled to coincide with the end of the six month moratorium. There are currently five wells producing at the Gomez Hub.

ATP operates the Gomez Hub with a 100% working interest at MC 711 and 755 and a 75% working interest at MC 754.

Canyon Express Hub Update

At the MC 305 #2 natural gas well, ATP began an abandonment operation of one reservoir and a sidetrack into the same reservoir at an updip location. These operations were conducted in accordance with the abandonment permit issued on November 11, 2009 and the sidetrack permit issued May 12, 2010. As a result of the May 30, 2010 NTL, ATP will complete the abandonment operation but will temporarily suspend the sidetrack of the natural gas well. There are currently three wells producing at the Canyon Express Hub.

ATP operates the Canyon Express Hub with an approximate 50% working interest in the wells and associated pipelines.