ATP Oil Gas Corporation IPAA 2002 Oil

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

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

ATP Oil & Gas Corporation Forward-looking Statement This presentation contains projections and other forward looking statements within the meaning of Section 27 A of the Securities Act of 1933 and Section 21 E 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

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

ATP Oil & Gas Corporation Company Overview • Founded in 1991 • A “D & P” company • Development and Production • Offshore solution provider for explorationoriented 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

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 The Company is incorporated on August 8 th 1991 1995 ATP becomes one of the first independents to utilize horizontal drilling in offshore operations 1996 ATP acquires all properties of Statoil (US) on the outer. Continental Shelf of the Gulf of Mexico 1997 ATP completes its first sub-sea development 1998 ATP awarded UKCS Blocks 42/25 a and 43/21 a 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 1999 ATP wins numerous awards for its outstanding technological achievements and growth record 2000 2001 ATP acquires its first properties in the UK North Sea 2002

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

ATP Oil & Gas Corporation Production Oil/Natural Gas (Bcfe) 24. 5 25. 7 17. 3 9. 9 2. 8 1997 2001 1998 1999 2000 ATP Oil & Gas Corporation

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

ATP Oil & Gas Corporation Proved Reserve Per Share (Mcfe per share) 11. 6 8. 8 7. 3 4. 4 1997 2001 4. 2 1998 1999 2000 ATP Oil & Gas Corporation

ATP Oil & Gas Corporation Reserve Replacement Average Reserve Replacement: 1997 -2000 259% 2001 527% ATP Oil & Gas Corporation

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

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

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

ATP Oil & Gas Corporation 2002 Production Guidance Gulf of Mexico 2001 2002 1 Q 02 25. 7 Bcfe (82% gas) 26. 0 Bcfe (75% gas) 6. 2 Bcfe 6. 5 Bcfe Guidance for future quarterly production will be given during the year. First U. K. North Sea production is scheduled for 2003. Oil & Gas Corporation

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

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

ATP Oil & Gas Corporation Strong Development Track Record Inception (1991) – March 31, 2002 PUD’s taken to production PUD’s in development planning Extensive Subsea Expertise Subsea Wells Operated Subsea Development Wells Planned Industry Leader in Long Reach Subsea Tiebacks - Ladybug 28 12 10 7 18 miles 100% of properties under development are operated, allowing control of the timing and amount of capital expenditure

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

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

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

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

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

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

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 • 2002 cash flow estimates • Proved reserves @12/31/01 $2. 46 $2. 10 -$2. 50 11. 6 Mcfe ATP Oil & Gas Corporation

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