1. 1 ATP Oil & Gas Corporation The Seventh Oil & Gas Conference August 5-8, 2002 ATP Oil & Gas Corporation

2. 2 Taking a business approach to the oil and gas business. ATP Oil & Gas Corporation

3. 3 ATP Oil & Gas Corporation Forward-looking Statement This presentation contains projections and other forward looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. These projections and statements reflect the Company’s current view with respect to future events and financial performance. No assurances can be given, however, that these events will occur or that these projections will be achieved, and actual results could differ materially from those projected as result of certain factors. A discussion of these factors is included in the Company documents filed with the Securities and Exchange Commission. This presentation does not constitute an offer to sell, or a solicitation of an offer to buy, any securities, or the solicitation of a proxy or an attempt to influence any voting of securities, by any person. ATP Oil & Gas Corporation

4. 4 ATP Oil & Gas Corporation Area of Operations Over 50 blocks in Gulf of Mexico 7 blocks in North Sea ATP Oil & Gas Corporation

5. 5 ATP Oil & Gas Corporation Company Overview Founded in 1991 A “D & P” company Development and Production Offshore solution provider for exploration-oriented majors and independents ATP technical staff average 21 years industry experience Win-Win Solution Provider Seller eliminates future capital expenditures on non-core assets, but receives cash flow ATP eliminates exploration risk, cost and time ATP Oil & Gas Corporation

6. 6 ATP Oil & Gas Corporation Company History ATP was founded in 1991 and completed an initial public offering in February 2001 1995 2002 199719991996 1991 The Company is incorporated on August 8th ATP acquires the third-party interests from its two partnerships and enters into a new financing arrangement ATP completes its first sub-sea development ATP wins numerous awards for its outstanding technological achievements and growth record ATP acquires all properties of Statoil (US) on the outer- Continental Shelf of the Gulf of Mexico ATP acquires its first properties in the UK North Sea ATP becomes one of the first independents to utilize horizontal drilling in offshore operations ATP opens the U.K. office commencing operations in the Southern Gas Basin of the UK North Sea 199820002001 ATP awarded UKCS Blocks 42/25a and 43/21a by DTI as an Out of Round License ATP Oil & Gas Corporation

7. 7 ATP Oil & Gas Corporation 2001 Benchmarks Production Reserves Reserve Replacement Oil & Gas Revenues EBITDA Debt ATP Record Almost Doubled 527% Grew by 7% Over 62% of revenues for 6 straight years Reduced by 14% ATP Oil & Gas Corporation

8. 8 ATP Oil & Gas Corporation Production Oil/Natural Gas (Bcfe) 25.7 24.5 17.3 9.9 2.8 1997 1998 1999 2000 2001 ATP Oil & Gas Corporation

9. 9 ATP Oil & Gas Corporation Proved Reserves (Bcfe) 235 125 104 50 46 1997 1998 1999 2000 2001 ATP Oil & Gas Corporation

10. 10 ATP Oil & Gas Corporation Proved Reserves Per Share ATP Oil & Gas Corporation 1997 1998 1999 2000 2001 11.6 8.8 7.3 4.2 4.4 (Mcfe per share)

11. 11 ATP Oil & Gas Corporation Reserve Replacement Average Reserve Replacement: 1997-2000 259% 2001527% ATP Oil & Gas Corporation

12. 12 ATP Oil & Gas Corporation Five Year Historical Operating Performance ($ in millions) 1997 1998 1999 2000 2001 68% 72% 62% 65% 62% $94 $84 $55 $43 $27 $20 $15 $8$5 EBITDAREVENU ES $58 Margin ATP Oil & Gas Corporation Note: Revenues reflect the effects of settled hedging activity

13. 13 ATP Oil & Gas Corporation Discretionary Cash Flow ATP Oil & Gas Corporation $17 $43 $47 1999 2000 2001 ($ in millions) Cash flow is EBITDA less interest expense

14. 14 ATP Oil & Gas Corporation Debt Reduction ATP Oil & Gas Corporation 2000 2001 $100 Million $116 Million

15. 15 ATP Oil & Gas Corporation ATP Oil & Gas Corporation 2002 Actual First Half Results and Updated Guidance

16. 16 ATP Oil & Gas Corporation 2002 Operating Performance ATP Oil & Gas Corporation ($ in millions) EBITDA Margin 69% for first six months Note: Revenues reflect the effects of settled hedging activity

17. 17 ATP Oil & Gas Corporation 2002 Operating Performance ATP Oil & Gas Corporation ($ in millions)

18. 18 ATP Oil & Gas Corporation Debt Reduction Program ATP Oil & Gas Corporation ($ in millions)

19. 19 ATP Oil & Gas Corporation Debt Per Proved Mcfe ATP Oil & Gas Corporation

20. 20 ATP Oil & Gas Corporation First Half 2002 Capital Liquidity Improvement ATP Oil & Gas Corporation Working Capital (1) Increased $12.2 million Bank and Subordinated DebtDecreased $10.0 million Overall Capital Liquidity Improvement$22.2 million ATP has positive working capital as of June 30, 2002 (1) (1) Excludes current maturities and mark-to-market of hedges and derivatives

21. 21 ATP Oil & Gas Corporation 2002 Development Projects Gulf of Mexico With capital of less than $20 million ATP is moving 32 Bcfe to proved developed producing properties (PDP) ATP Oil & Gas Corporation

22. 22 ATP Oil & Gas Corporation 2002 Development Projects North Sea ATP is presently developing the Helvellyn project (Block 47/10) with production scheduled for 2003 ATP Oil & Gas Corporation

23. 23 ATP Oil & Gas Corporation Offshore Expertise ATP has extensive subsea expertise Subsea wells operated 10 Subsea development wells planned 7 Industry leader in long reach subsea tiebacks - Ladybug18 miles ATP Oil & Gas Corporation

24. 24 ATP Oil & Gas Corporation Operating Control 100% of properties under development are operated, allowing control of the timing and amount of capital expenditure ATP Oil & Gas Corporation

25. 25 ATP Oil & Gas Corporation 2002 Updated Production Guidance Gulf of Mexico Production: Original full year guidance 26.0 Bcfe (75% gas) Revised full year guidance 26.5 Bcfe (70% gas) Original first half guidance 12.7 Bcfe (65% gas) Actual first half performance 14.9 Bcfe (67% gas) 3Q02 6.5 Bcfe (74% gas) Guidance for future quarterly production will be given during the year. First U.K. North Sea production is scheduled for 2003. ATP Oil & Gas Corporation

26. 26 ATP Oil & Gas Corporation 2002 Updated Expense Guidance Gulf of Mexico LOE: Original full year guidance$0.70/Mcfe Revised full year guidance$0.54/Mcfe Actual first half$0.49/Mcfe ATP Oil & Gas Corporation

27. 27 ATP Oil & Gas Corporation ATP Upside Outer Continental Shelf Shallow Deepwater Gulf North Sea ATP Oil & Gas Corporation

28. 28 ATP Oil & Gas Corporation Property Overview ATP Oil & Gas Corporation Gulf of Mexico Shelf Program Future developments on the shelf

29. 29 ATP Oil & Gas Corporation Garden Banks 409 (Ladybug) Gulf of Mexico Shallow Deepwater Ladybug ATP Operated 2 million barrels produced after 300 days ATP Oil & Gas Corporation Future developments in deep water

30. 30 ATP Oil & Gas Corporation Southern Gas Basin of North Sea ATP Oil & Gas Corporation

31. 31 ATP Oil & Gas Corporation Southern Gas Basin of North Sea ATP Acquisition Blocks The Tors Helvellyn 2002 Development Venture ATP Oil & Gas Corporation 49/12a

32. 32 ATP Oil & Gas Corporation Investment Considerations  Six straight years of increases of Production Reserves Revenues EBITDA Cash Flow  12 undeveloped projects with over 150 Bcfe of proved reserves to be developed in 2002 – 2004 100% operated by ATP  Proved reserves per share @12/31/01 11.6 Mcfe ATP Oil & Gas Corporation  Significantly improved liquidity

33. 33 ATP Oil & Gas Corporation NASDAQ: ATPG ATP Oil & Gas Corporation 4600 Post Oak Place, Suite 200 Houston, TX 77027-9726 713-622-3311 www.atpog.com ATP Oil & Gas Corporation