ATP Begins Wenlock Production

ATP Oil & Gas announced first production from its Wenlock W1 well in Block 49/12a of the Southern Gas Basin of the U.K. North Sea. The company's wholly-owned subsidiary, ATP Oil & Gas (U.K.) Limited, is the operator and owns a 100% working interest. The well tested at a rate of 58 MMcf/d, the limit of the test equipment, in July 2007. Based on initial flows the well has the capacity to exceed this level during normal operations. T. Paul Bulmahn, ATP Chairman and President stated, "ATP delivered a step change in year-end exit rate from 67 MMcfe/d at year-end 2005 to over 170 MMcfe/d at year-end 2006. For 2007, ATP once again set ambitious objectives to take production to a record 300 MMcfe/d by year-end. Wenlock production should continue to ramp up during the next few weeks to help us achieve this milestone."

The Wenlock W1 well was completed in the Rotliegend Leman sandstone in two fault blocks. One fault block contained the targeted proved undeveloped reserves included in ATP's year-end 2006 reserve report. The second fault block contained additional natural gas reserves which were not included in ATP's 2006 reserve report as proved reserves. ATP believes a portion of the reserves in the second fault block will be classified as proved in ATP's 2007 reserve report. Located in 75 feet of water, the Wenlock W1 well is the first phase of the company's development plan in this hub area. Significant upside exists at the Wenlock hub with two additional drilling opportunities currently being evaluated.