ATP Mississippi Canyon Well Test Successful at 134 Mmcfe/d

ATP Oil & Gas tested the Mississippi Canyon 711 ("MC 711" or "Gomez") #4 ST1 well with a total test rate of 13,610 BOPD and 52.7 MMcf/d or 134 MMcfe/d. The multiple day flow test recorded flowing tubing pressures exceeding 3500 psi with very little reservoir drawdown. The MC 711 #4 ST1 well logged approximately 157 total net feet of oil and gas pay in Lower Pliocene sands.

"This successful test confirmed the location of the original sands and established flow rates and pressures which exceeded our expectations. In addition, the test creates the possibility for additional developmental drilling to more completely exploit the two primary pay sands as well as three other oil and gas sands that exist at shallower depths" said T. Paul Bulmahn, ATP's Chairman and President. "MC 711 should provide a dramatic increase to ATP's production in the fourth quarter of 2005."

ATP's development plans for Gomez include retrofitting a mobile production platform, installing subsea well equipment and laying gas and oil pipelines. In 2005, ATP plans to reenter a second well, located approximately 2100' away from the tested well, which contains the same two zones that were tested in the #4 ST1 well. Anticipated first production from the two wells has been recently accelerated to the fourth quarter of 2005. The same two zones also exist in the #5 well located 9800' north of the tested well. ATP is the operator with a 99% working interest.