ATP Oil & Gas Corporation

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

2. A T P Oil & Gas Corporation Taking a business approach to the oil and gas business.

3. A T P ATP Oil & Gas Corporation Forward-looking Statement Oil & Gas Corporation 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.

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

5. A T P ATP Oil & Gas Corporation Company Overview Oil & Gas Corporation • 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

6. A T P ATP Oil & Gas Corporation Company History Oil & Gas Corporation ATP was founded in 1991 and completed an initial public offering in February 2001 ATP acquires the third-party interests from its two partnerships and enters into a new financing arrangement ATP acquires all properties of Statoil (US) on the outer-Continental Shelf of the Gulf of Mexico ATP awarded UKCS Blocks 42/25a and 43/21a by DTI as an Out of Round License ATP opens the U.K. office commencing operations in the Southern Gas Basin of the UK North Sea The Company is incorporated on August 8th 2002 1991 1995 1996 1997 1998 1999 2000 2001 ATP becomes one of the first independents to utilize horizontal drilling in offshore operations ATP completes its first sub-sea development ATP wins numerous awards for its outstanding technological achievements and growth record ATP acquires its first properties in the UK North Sea

7. A T P ATP Oil & Gas Corporation 2001 Benchmarks Oil & Gas Corporation 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

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

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

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

11. A T P ATP Oil & Gas Corporation Reserve Replacement Oil & Gas Corporation • Average Reserve Replacement: • 1997-2000 259% • 2001 527%

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

13. A T P ATP Oil & Gas Corporation Historical Operating Performance Oil & Gas Corporation ($ in millions) $94 EBITDA REVENUES $84 $58 $55 $43 $27 $20 $15 $8 $5 1997 1998 1999 2000 2001 68% 72% 62% 65% 62% Margin

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

15. A T P ATP Oil & Gas Corporation 2002 Production Guidance Oil & Gas Corporation Gulf of Mexico 2001 25.7 Bcfe (82% gas) 2002 26.0 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.

16. A T P ATP Oil & Gas Corporation 2002 Development Projects Oil & Gas Corporation Gulf of Mexico South Marsh Island 189 PDNP to PDP Projected start date April 2002 Actual first production March 18, 2002 Eugene Island 71 PUD to PDP Pipeline installation ongoing Projected start date 2nd Quarter West Cameron 101 PUD to PDP Projected start date 4th Quarter 13 workovers PDNP to PDP Capital less than $20 million 32 Bcfe moved to PDP

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

18. A T P ATP Oil & Gas Corporation Strong Development Track Record Oil & Gas Corporation • Inception (1991) – March 31, 2002 • PUD’s taken to production 28 • PUD’s in development planning 12 • Extensive Subsea Expertise • Subsea Wells Operated 10 • Subsea Development Wells Planned 7 • Industry Leader in Long Reach Subsea Tiebacks • - Ladybug 18 miles 100% of properties under development are operated, allowing control of the timing and amount of capital expenditure

19. A T P ATP Oil & Gas Corporation Operational Expertise of Senior Technical Staff Oil & Gas Corporation Name Age 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 – Projects UK North Sea, Texaco - Drilling Engr Manager–Gulf of Mexico North Sea, Texaco

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

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

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

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

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

25. A T P ATP Oil & Gas Corporation Investment Considerations Oil & Gas Corporation Six straight yearsof 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 @12/31/01 11.6 Mcfe

26. A T P ATP Oil & Gas Corporation Oil & Gas Corporation NASDAQ: ATPGATP Oil & Gas Corporation4600 Post Oak Place, Suite 200Houston, TX 77027-9726713-622-3311www.atpog.com