1. ATP Oil & Gas Corporation IPAA 2002 Oil & Gas Investment Symposium April 22-24, 2002 ATP Oil & Gas Corporation

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

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. ATP Oil & Gas Corporation Area of Operations Over 50 blocks in Gulf of Mexico 7 blocks in North Sea WC 101 WC 152 ATP Oil & Gas Corporation

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

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

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

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

13. ATP Oil & Gas Corporation 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

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

15. ATP Oil & Gas Corporation 2002 Production Guidance Gulf of Mexico 200125.7 Bcfe (82% gas) 200226.0 Bcfe (75% gas) 1Q02 6.2 Bcfe 2Q02 6.5 Bcfe 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

16. ATP Oil & Gas Corporation 2002 Development Projects Gulf of Mexico South Marsh Island 189PDNP to PDP Projected start dateApril 2002 Actual first productionMarch 18, 2002 Eugene Island 71PUD to PDP Pipeline installation ongoing Projected start date2 nd Quarter West Cameron 101PUD to PDP Projected start date4 th Quarter 13 workoversPDNP to PDP Capital less than $20 million32 Bcfe moved to PDP ATP Oil & Gas Corporation

17. ATP Oil & Gas Corporation 2002 Development Projects UK North Sea Helvellyn (Block 47/10) PUD to PDNP Under development PDP 2003 ATP Oil & Gas Corporation

18. ATP Oil & Gas Corporation Strong Development Track Record Inception (1991) – March 31, 2002 PUD’s taken to production 28 PUD’s in development planning12 Extensive Subsea Expertise Subsea Wells Operated 10 Subsea Development Wells Planned 7 Industry Leader in Long Reach Subsea Tiebacks - Ladybug18 miles 100% of properties under development are operated, allowing control of the timing and amount of capital expenditure ATP Oil & Gas Corporation

19. ATP Oil & Gas Corporation Operational Expertise of Senior Technical Staff NameAge Background Leland E Tate 54 - President, ARCO North Africa - Dir. General, ARCO Joint Ventures Senior Vice President - Dir. Operations, ARCO British Ltd, North Sea Operations - VP Engineering, ARCO International - Vice President, ARCO Gulf of Mexico Adrian Turner 47 - President, ARCO Middle East - Managing Dir, ARCO Asia Pacific Managing Director - Commercial Vice President, BP Amoco ATP Oil & Gas (UK) Ltd. - Commercial Negotiator, ARCO UK and Conoco, North Sea G. Ross Frazer 46 - Operations & Engr. Manager, British-Borneo Exploration, Inc. Vice President - - Chairman, API Houston Chapter Advisory Engineering - Member, APIHouston Chapter–Deep Water Operations Steering Committee Robert M. Shivers 44 - Commercial/Development Manager – Deepwater Gulf of Mexico, Texaco Vice President - - Asset and Project Team Manager – ProjectsUK North Sea, Texaco - Drilling Engr Manager–Gulf of Mexico North Sea, Texaco ATP Oil & Gas Corporation

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

21. ATP Oil & Gas Corporation Property Overview Gulf of Mexico Shelf Program WC 101 WC 152 ATP Oil & Gas Corporation

22. ATP Oil & Gas Corporation Garden Banks 409 (Ladybug) Gulf of Mexico Shallow Deepwater WC 101 WC 152 Ladybug ATP Operated 1 million barrels produced after 135 days ATP Oil & Gas Corporation

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

24. ATP Oil & Gas Corporation Southern Gas Basin of North Sea ATP Acquisition Blocks Other Opportunities The Tors Helvellyn Venture ATP Oil & Gas Corporation

25. ATP Oil & Gas Corporation Investment Considerations  Six straight years of increases of Production Reserves Revenues EBITDA Cash Flow  12 projects, 100% operated by ATP  Per share amounts 2001 cash flow$2.46 2002 cash flow estimates$2.10-$2.50 Proved reserves @12/31/0111.6 Mcfe ATP Oil & Gas Corporation

26. 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