ATP Oil & Gas Corporation today announced the successful completion and testing of the Wenlock W1 well in Block 49/12a of the Southern Gas Basin of the U.K. North Sea. The well flowed at a rate of 58 MMcf/d, the limit of the test equipment, and 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 reserves which had not been included in ATP's year-end report of proved reserves. The company's wholly-owned subsidiary, ATP Oil & Gas (U.K.) Limited, is the operator and owns a 100% working interest.

With first production scheduled for winter 2007, Wenlock is expected to add production of approximately 50-60 MMcf/d to current company production levels. 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 to the development scenario exists at the Wenlock hub with two additional drilling opportunities currently being evaluated.

T. Paul Bulmahn, Chairman and President of ATP stated, "Wenlock will significantly contribute to ATP's ramp in production in the North Sea. Not only does the second fault block provide increased production, it also contributes additional oil and gas reserves to the proved category. I commend our outstanding team effort for achieving this accomplishment."