ATP Ends 2006 With Record Reserves and Production.

HOUSTON -- ATP Oil & Gas Corporation (NASDAQ:ATPG) today announced record reserves in all categories, an annual production increase of 155% and a robust reserves replacement ratio of 315%.

Reserves and Production - ATP reported independent third-party year-end 2006 total proved reserves of 637 Bcfe, an increase of 109 Bcfe (+21%) and proved plus probable reserves of 1,005 Bcfe, an increase of 246 Bcfe (+32%). Equally impressive was the growth in proved developed reserves, increasing 85 Bcfe (+67%) to 214 Bcfe.

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ATP's record production of 50.9 Bcfe includes the Gulf of Mexico, 38.7 Bcfe (+107%) and the North Sea, 12.2 Bcfe (+869%). Even with record production in both areas, ATP achieved a 315% proved reserve replacement ratio for 2006. For the three-year period ending December 31, 2006, ATP achieved a three-year reserve replacement ratio of 459% from production of 93 Bcfe and 427 Bcfe in net reserve additions from all sources during the 2004 - 2006 period. Costs incurred for oil and gas expenditures for the same three-year period were $1.17 billion, which when divided by three-year reserve additions from all sources, results in three-year finding and development costs of $2.75 per Mcfe.

All reserves and hydrocarbons included in this release are shown net to ATP's working interest ("W.I."). On March 5, ATP will make accessible copies of certification letters from its independent third-party reservoir engineers under the Investor Info-Annual/Quarterly Reports section of its website at www.atpog.com.

In addition to third-party proved and probable reserves, ATP estimates logged hydrocarbons for properties that have been recently acquired and for properties that have not yet been evaluated by its third-party reservoir engineers. For example, on August 3, 2006, management estimated 360 Bcfe of logged hydrocarbons not included in ATP's December 31, 2005 reserve report. At December 31, 2006, 297 Bcfe (+83%) of the 360 Bcfe were recognized as proved or probable reserves in the company's third-party engineering reports.

Recoverable hydrocarbons not yet recognized as proved and probable by third-party reservoir engineers include 22 Bcfe at Green Canyon 37 (currently in third-party reservoir engineers' possible reserves) and 38 Bcfe at Cheviot (management's estimate of additional recoverable hydrocarbons). In addition, 16 Bcfe at Garden Banks 388, 12 Bcfe at Ship Shoal 351 and 9 Bcfe at High Island 392 have not yet been evaluated by third parties. Management's estimate of 156 Bcfe shown in the previous table includes these properties as well as year-to-date 2007 acquisitions.

ATP's 1,005 Bcfe of proved and probable reserves are located 47% in the Gulf of Mexico Deepwater, 10% on the Gulf of Mexico Shelf and 43% in the North Sea.

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PV10 and Valuation - At December 31, 2006, ATP's SEC pre-tax PV-10 of proved reserves was $1.3 billion, and the pre-tax PV-10 of proved and probable reserves was $2.4 billion (SEC year-end prices). At December 31, 2006, the pre-tax PV-10 of proved, probable and logged hydrocarbons of 1,161 Bcfe was $4.3 billion (strip prices at December 29, 2006).

Top Properties - Based on proved and probable reserves, ATP's top five properties are listed below. Collectively, the top five properties, all of which are operated by ATP, represent 77% of proved and probable reserves. The Gomez Hub (100% W.I.) and Tors Hub (85% W.I.) are currently producing with additional development planned in 2007. ATP plans major infrastructure development at its Telemark Hub (100% W.I) in 2007 with first production scheduled for late 2008. ATP expects to receive field development plan approval at Cheviot (100% W.I.) in mid-2007, at which time the company will finalize engineering and begin procurement. Development is scheduled for 2008 and 2009 with first production in late 2009. The Canyon Express Hub, which includes King's Peak (55% W.I.), is scheduled for development in 2008 and 2009.

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ATP announced two major acquisitions in January 2007. The first acquisition was at ATP's Canyon Express Hub and included a 50% W.I. at Aconcagua, a 17% W.I. at Camden Hills and an increase to a 45% W.I. in the Canyon Express Pipeline. With King's Peak, ATP now has a working interest in six blocks in its Canyon Express Hub. The second acquisition was at ATP's Gomez Hub and included a 100% W.I. at Anduin and the potential to earn a 50% W.I. at Anduin West and a 25% W.I. at Gladden (following the successful completion of Anduin). ATP began drilling Anduin in January 2007. The drilling rig has encountered the productive reservoir and completion operations are underway. Anduin will be tied back to the ATP Innovator at Mississippi Canyon 711 and is scheduled to be placed on production in mid-2007. These recent acquisitions are not included in ATP's December 2006 reserve report. Management's current estimate of recoverable hydrocarbons is 47 Bcfe at Anduin and 13 Bcfe at Aconcagua.

About ATP Oil & Gas

ATP Oil & Gas is an international offshore oil and gas development and production company with operations in the Gulf of Mexico and the North Sea. The company trades publicly as ATPG on the NASDAQ Global Select Market. For more information about ATP Oil & Gas Corporation, visit www.atpog.com.

Reserve Reports

ATP's 2006 proved and probable reserve reports were prepared by independent third-party reservoir engineers. The proved reserve quantities and classifications contained in the reports prepared by the independent third-party reservoir engineers conform to the definition as set forth in accordance with parameters established by the Securities and Exchange Commission ("SEC") Regulation S-X Part 210.4-10 (a) as clarified by subsequent Commission Staff Accounting Bulletins.

Forward-looking Statements 

Certain statements included in this news release are "forward-looking statements" under the Private Securities Litigation Reform Act of 1995. ATP cautions that assumptions, expectations, projections, intentions, or beliefs about future events may, and often do, vary from actual results and the differences can be material. Some of the key factors which could cause actual results to vary from those ATP expects include changes in natural gas and oil prices, the timing of planned capital expenditures, availability of acquisitions, uncertainties in estimating proved reserves and forecasting production results, operational factors affecting the commencement or maintenance of producing wells, the condition of the capital markets generally, as well as our ability to access them, and uncertainties regarding environmental regulations or litigation and other legal or regulatory developments affecting our business. The SEC has generally permitted oil and gas companies, in filings made with the SEC, to disclose only proved reserves that a company has demonstrated by actual production or conclusive formation tests to be economically and legally producible under existing economic and operating conditions. ATP and its independent third-party reservoir engineers use the terms "probable" and "possible" and ATP uses the term "recoverable hydrocarbons" to describe volumes of reserves potentially recoverable through additional drilling or recovery techniques that the SEC's guidelines may prohibit ATP from including in filings with the SEC. These estimates are by their nature more speculative than estimates of proved reserves. All estimates of probable and possible reserves in this news release have been prepared by ATP's independent third-party reservoir engineers and all estimates of recoverable hydrocarbons have been prepared by management. More information about the risks and uncertainties relating to ATP's forward-looking statements are found in the company's SEC filings.