SPE GCS General Meeting Luncheon

March 14, 2002

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.

Company Overview

Founded in 1991

A “D & P” company– Development and Production– Offshore solution provider for exploration-oriented majors and

independents

Geographic Focus– Over 50 offshore blocks acquired in Gulf of Mexico– Acquired 7 offshore blocks in North Sea

Strategy and property overview

Company StrategyAcquire, develop and produce proved reserves

WC 152

WC 101

Company history

ATP was founded in 1991 and completed an initial public offering in February 2001

1995 200220021997 199919961993 1994

ATP forms its first limited partnership to provide funding

for operations

1991

The Company is

incorporated

on August 8th

ATP forms a second

partnership and commences development

activities in the Gulf of Mexico

ATP acquires the third-party

interests from its two partnerships and enters into a

new financing arrangement

The Company 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

The Company completes its initial

public offering in February and

acquires its first properties in the UK

North Sea

ATP becomes one of the first independent development companies 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

1998 2000 2001

ATP awarded UKCS Blocks 42/25a and

43/21a by DTI as an Out of

Round License

Strong development track record

Inception (1991) – December 31, 2001PUD’s taken to production 28PUD’s in development planning 12

Extensive Subsea ExpertiseSubsea Wells Operated 10Subsea Development Wells Planned 7Industry 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

Taking Gulf Technology to the North Sea

SPE Presentation Title

North Sea

UK Southern Gas Basin

North Sea Southern Gas Basin

Garden Banks 409 (Ladybug)

WC 152

WC 101

Ladybug

•ATP Operated

•Two subsea wells

Ladybug Umbilical

Subsea Development

Garden Banks 409 (Ladybug)

WC 152

WC 101

Ladybug

•1 million barrels produced after 135 days

2001 Benchmarks

Production

Reserves

Reserve Replacement

Debt

Revenues

EBITDA

Cash Flow

2001 Benchmarks

Production

Reserves

Reserve Replacement

Debt

Revenues

EBITDA

Cash Flow

ATP Record

From 125 Bcfe in 2000 to 235 Bcfe in 2001

527%

Reduced 14%

Grew by 5+%

64+% of Revenues Over 62% for 6 straight years

Grew by 10+%

Operational Expertise of Senior Officers

Name Age BackgroundLeland E Tate 54 - President, ARCO North Africa Senior Vice President - Director General, ARCO Joint Ventures Operations - Director of Operations, ARCO British Ltd, North Sea

- VP Engineering, ARCO International - Vice President, ARCO Gulf of Mexico

Adrian Turner 47 - President, ARCO Middle East Managing Director - Managing Director, ARCO Asia Pacific ATP Oil & Gas (UK) Ltd. - Commercial Vice President, BP Amoco

- Commercial Negotiator, ARCO UK and Conoco, North Sea

G. Ross Frazer 46 - Operations and Engineering Manager, British-Borneo Exploration, Inc. Vice President - - Chairman, American Petroleum Institute Houston Chapter Advisory Board Engineering - Member, American Petroleum Institute Houston 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 – UK North Sea, Texaco Projects - Drilling Engineering Manager – Gulf of Mexico/North Sea, Texaco

Southern Gas Basin (SGB)

ATP Acquisition Blocks

Investment Considerations

Six straight years of increases inProductionReservesRevenuesEBITDACash flow

ATP UpsideNorth SeaShallow deepwater GOMOuter Continental Shelf

E&P Valuation Table Sorted by Enterprise Value to 2002 EBITDAWachovia Securities Master E&P Valuation Table - Sorted By Enterprise Value To 2002 EBITDA (EV / EBITDA)

Market Enterprise Debt To Debt Price/ Price/ EV / Total Reserve 3-Yr AvgStock 52-Week Cap Value Capital Per Price Performance EPS CFPS EBITDA EV / EV / Reserves % North Life F&D Costs Recycle

As of 2/28/02 (Close) Ticker Price High Low ($MM) ($MM) Ratio Boe YTD WTD 02E 02E 2002E BOE MCFE (MMBOE) Amer. Gas (Years) ($/MCFE) Ratio

ATP Oil & Gas Corporation ATPG $1.70 $14.13 $1.47 $34.5 $114.6 59.5% $2.29 (43.0%) 1.2% NM 0.8x 2.2x $3.25 $0.54 35.0 85.0% 8.6 $1.26 1.2xClayton Williams Energy, Inc. CWEI 9.61 22.35 8.10 90.4 147.4 39.0% 3.23 (26.6%) (5.2%) NM 1.9x 2.4x 6.90 1.15 17.6 26.8% 4.7 1.51 1.4xEnergy Partners, Ltd. EPL 8.15 14.00 5.60 219.0 244.5 13.2% 0.71 7.9% 1.2% NM 3.2x 3.5x 6.85 1.14 35.7 22.9% 9.5 0.84 2.6xThe Meridian Resource Corporation TMR 3.43 8.60 2.65 185.3 375.3 50.4% 3.72 (14.0%) (0.6%) 22.9x 2.3x 3.8x 7.16 1.19 51.1 56.3% 5.9 1.94 1.0xDenbury Resources Inc. DNR 7.05 12.30 5.84 374.7 489.3 24.4% 1.14 (3.6%) 2.5% 54.2x 3.8x 3.9x 4.86 0.81 100.6 28.5% 12.9 1.08 1.3xStone Energy Corporation SGY 36.87 59.40 29.66 965.4 1,065.4 11.3% 1.50 (6.7%) 4.9% 20.4x 4.0x 4.3x 15.82 2.64 66.7 68.0% 6.3 1.54 1.4xSouthwestern Energy Company SWN 11.20 16.35 8.77 287.0 643.3 67.0% 5.62 7.7% (0.4%) 24.9x 3.7x 4.2x 6.68 1.11 63.4 87.2% 10.7 1.06 NE Houston Exploration Company THX 31.25 38.00 22.20 961.5 1,121.5 22.1% 1.71 (6.9%) 5.5% 30.0x 3.9x 4.5x 11.87 1.98 93.6 94.3% 7.0 1.43 1.4xComstock Resources, Inc. CRK 6.60 13.15 4.95 224.2 448.2 52.4% 3.07 (5.7%) 3.1% 82.5x 2.9x 4.6x 6.64 1.11 67.1 73.9% 10.6 1.18 1.5xRange Resources Corporation RRC 4.66 6.68 3.93 240.9 650.5 60.6% 4.21 2.4% (0.9%) 29.1x 2.4x 4.9x 6.48 1.08 97.3 73.3% 28.9 2.02 1.3xNuevo Energy Company NEV 13.75 21.56 11.10 232.1 641.6 63.0% 1.65 (8.3%) 0.0% NM 2.9x 5.1x 2.50 0.42 247.6 11.2% 12.4 0.75 0.5xChesapeake Energy Corporation CHK 6.27 11.06 4.50 1,068.3 2,336.7 67.4% 4.35 (5.1%) 6.6% 17.9x 3.2x 5.3x 7.75 1.29 291.7 91.0% 13.0 1.05 1.3xNoble Affiliates, Inc. NBL 36.20 51.09 27.50 2,069.6 2,705.2 38.1% 1.61 2.6% 6.0% NM 4.7x 5.4x 6.56 1.09 394.5 31.8% 11.5 1.28 1.4xKey Production Company, Inc. KP 16.68 24.70 10.85 236.2 271.2 17.4% 1.36 (1.9%) 6.6% 21.4x 5.1x 5.6x 10.57 1.76 25.6 63.8% 6.7 1.60 1.4xVintage Petroleum, Inc. VPI 10.50 22.45 7.85 672.7 1,689.1 58.1% 2.08 (27.3%) 21.1% NM 3.7x 5.8x 3.11 0.52 489.1 14.9% 17.0 0.44 2.8xNewfield Exploration Company NFX 36.29 41.75 26.25 1,770.9 2,164.5 34.1% 2.50 2.2% 2.2% 28.6x 4.7x 5.5x 13.72 2.29 157.2 75.4% 6.8 1.48 1.4xUnocal Corporation UCL 35.95 40.00 29.51 8,792.1 11,642.1 47.1% 1.57 (0.3%) 1.2% 31.3x 5.3x 5.5x 5.62 0.94 1,814.1 19.0% 9.5 1.24 0.9xPogo Producing Company PPP 26.92 34.50 20.45 1,628.1 2,385.1 47.6% 2.54 2.5% 6.8% 41.4x 4.3x 5.9x 7.95 1.33 298.2 32.9% 14.8 1.21 1.0xPatina Oil & Gas Corporation POG 27.20 33.80 20.99 616.7 704.4 24.9% 0.73 (1.1%) 1.9% 14.6x 5.3x 5.8x 5.86 0.98 119.9 73.2% 16.5 0.25 6.7xKerr-McGee Corporation KMG 55.33 74.10 46.94 5,543.2 10,117.4 59.0% 3.05 1.0% 0.7% 33.1x 5.0x 5.7x 4.80 0.80 1,500.0 26.1% 13.8 1.06 1.8xMission Resources Corporation MSSN 2.80 9.55 2.55 66.3 332.1 65.9% 3.38 (20.0%) 2.6% NM 2.2x 5.9x 4.09 0.68 78.5 32.0% 10.4 --- --- Prize Energy Corp. PRZ 23.49 24.50 15.00 313.9 564.7 60.6% 2.25 1.6% 2.8% 12.8x 4.5x 6.1x 5.06 0.84 111.6 48.0% 14.9 0.56 --- XTO Energy Inc. XTO 18.80 21.73 12.30 2,346.2 3,156.2 50.7% 2.16 7.4% 5.5% 13.1x 5.2x 6.2x 8.28 1.38 375.4 78.6% 13.7 0.64 2.0xPure Resources, Inc. PRS 20.00 25.30 15.00 1,032.0 1,567.2 52.3% 2.16 (0.5%) (0.5%) NM 4.8x 6.0x 6.10 1.02 247.7 64.0% 11.0 0.60 2.5xWestport Resources Corporation WRC 18.22 32.09 12.60 948.4 1,406.4 33.7% 2.77 5.0% (3.8%) NM 5.1x 5.9x 7.69 1.28 155.0 55.5% 7.7 1.03 1.5xEncore Acquisition Company EAC 13.05 17.80 11.00 391.9 455.9 19.5% 0.62 (2.0%) (1.5%) 15.7x 5.5x 6.0x 4.42 0.74 102.8 12.2% 21.8 1.08 --- Magnum Hunter Resources, Inc. MHR 7.51 13.90 6.65 276.4 542.5 69.3% 4.35 (9.5%) 1.9% 32.7x 4.2x 6.1x 8.71 1.45 61.2 63.5% 13.4 1.26 2.0x

St. Mary Land & Exploration Company MARY 21.70 25.88 14.58 613.1 627.4 4.8% 0.24 2.4% 3.8% 44.3x 6.3x 6.4x 10.65 1.77 58.6 64.3% 6.7 1.11 1.5xApache Corporation APA 52.77 62.27 34.77 7,610.9 10,229.0 39.0% 1.82 5.8% 2.3% 20.9x 5.7x 6.4x 7.40 1.23 1,209.8 39.2% 13.3 0.90 2.2xUnit Corporation UNT 13.75 23.00 7.41 498.2 538.1 12.9% 0.99 6.6% 6.3% 17.9x 6.7x 7.0x 13.41 2.24 40.1 89.6% 10.8 0.85 2.7xPetroQuest Energy, Inc. PQUE 4.98 8.99 3.95 197.7 207.7 15.8% 0.73 (6.4%) (1.8%) NM 6.1x 5.8x 15.04 2.51 13.7 54.9% 16.7 1.33 1.5xRemington Oil & Gas Corporation ROIL 17.71 19.49 10.03 435.5 482.1 26.5% 1.85 2.4% 0.1% 59.0x 6.2x 6.5x 19.17 3.20 25.1 58.8% 7.4 0.95 2.9xBerry Petroleum Company BRY 13.30 17.75 11.00 295.3 328.3 18.1% 0.31 (15.3%) (6.8%) 12.1x 6.0x 6.2x 3.05 0.51 107.4 0.6% 19.6 0.65 1.8xCabot Oil & Gas Corporation COG 20.10 34.35 16.25 623.1 990.1 50.1% 1.86 (16.4%) 1.8% NM 4.9x 6.8x 5.01 0.84 197.5 89.1% 17.7 1.12 1.3xAbraxas Petroleum Corporation ABP 1.05 5.38 0.64 31.7 302.8 NM 6.66 (20.5%) 1.9% NM 8.1x 6.7x 5.96 0.99 40.7 78.3% 9.5 1.91 0.2x3TEC Energy Corporation TTEN 15.03 21.05 11.95 227.5 346.2 38.1% 2.73 7.4% 0.6% 36.7x 5.1x 6.8x 7.89 1.31 43.5 88.5% 10.6 0.74 2.7xSpinnaker Exploration Company SKE 41.02 48.00 30.00 1,162.3 1,162.3 0.0% --- (0.3%) 4.3% 31.8x 7.8x 7.1x 20.61 3.43 51.2 72.7% 10.2 1.69 1.7xPioneer Natural Resources Company PXD 19.82 23.05 12.62 1,972.5 3,527.1 56.8% 2.32 2.9% 4.4% 38.1x 5.2x 6.9x 5.22 0.87 671.4 48.3% 15.4 0.58 1.8xPlains Resources Inc. PLX 22.48 29.50 19.00 589.6 868.3 53.9% 1.17 (8.7%) (6.8%) 13.7x 5.8x 6.4x 3.43 0.57 238.7 6.5% 26.9 0.41 1.3xEOG Resources, Inc. EOG 35.19 50.70 25.80 4,122.2 4,970.7 35.5% 0.99 (10.0%) 3.4% 73.3x 6.4x 7.2x 7.05 1.18 704.9 62.7% 10.4 0.97 1.7xSwift Energy Company SFY 17.81 37.70 15.39 453.4 703.9 39.8% 2.39 (11.8%) 14.0% 52.4x 6.0x 7.8x 6.62 1.10 104.9 66.5% 15.0 1.54 1.4xForest Oil Corporation FST 25.69 37.85 22.75 1,245.3 1,901.1 40.4% 2.85 (8.9%) 3.3% NM 6.2x 7.6x 8.27 1.38 229.9 61.2% 7.6 1.16 1.3xMurphy Oil Corporation MUR 86.18 87.85 60.75 3,937.0 4,466.9 26.2% 1.20 2.5% 4.1% 36.2x 7.4x 7.7x 10.00 1.67 442.3 25.0% 11.7 0.87 2.4xOcean Energy, Inc. OEI 18.35 21.72 14.00 3,287.3 4,624.9 48.1% 2.23 (4.4%) 3.9% 31.6x 6.3x 7.7x 7.42 1.24 600.8 43.8% 12.1 1.03 1.4xCallon Petroleum Company CPE 4.35 13.49 3.96 58.3 232.0 52.9% 3.12 (36.5%) (4.2%) NM 3.7x 7.5x 4.03 0.67 55.6 40.0% 21.8 0.75 2.2xTom Brown, Inc. TMBR 27.56 36.75 19.65 1,104.6 1,202.4 14.4% 0.87 2.0% 4.0% NM 8.8x 8.3x 9.84 1.64 113.0 87.6% 10.9 0.87 1.9xDevon Energy Corporation DVN 43.68 66.75 30.55 7,024.7 14,979.2 64.3% 3.91 13.0% 3.0% 23.7x 4.4x 8.2x 7.06 1.18 2,036.2 55.2% 9.8 0.98 2.2xBurlington Resources, Inc. BR 37.58 51.99 31.69 7,703.9 12,186.9 54.8% 2.28 0.1% 1.4% NM 6.8x 8.6x 5.63 0.94 1,968.1 75.4% 13.1 0.92 1.5xQuicksilver Resources KWK 20.16 20.50 10.00 388.8 628.5 72.0% 2.15 5.8% 5.0% 43.8x 9.4x 9.4x 5.50 0.92 111.5 85.3% 19.8 0.54 1.8xPrima Energy Corporation PENG 21.74 37.00 19.10 286.8 286.8 0.0% --- (0.0%) 8.1% 32.9x 10.8x 10.4x 9.42 1.57 29.4 87.3% 15.6 0.54 4.2xAnadarko Petroleum APC 52.10 73.00 43.00 13,025.0 17,854.0 39.9% 2.05 (8.4%) 2.9% 25.9x 7.9x 10.4x 7.76 1.29 2,132.7 49.9% 11.2 1.05 1.8xEvergreen Resources, Inc. EVG 41.70 50.99 30.65 810.9 981.9 35.7% 0.98 8.0% 2.3% 51.5x 19.0x 19.4x 5.61 0.94 175.0 100.0% 32.0 0.40 3.6xPenn Virginia Corporation PVA 36.10 45.40 26.03 325.2 460.2 39.3% 3.46 5.9% 9.9% NM NE NE 10.46 1.74 39.0 88.4% 19.8 1.08 NE Equitable Resources, Inc. EQT 32.68 40.50 26.00 2,142.6 2,684.8 39.3% 1.47 (4.1%) 1.4% 13.6x NE NE 6.62 1.10 367.6 98.1% 24.5 0.71 NE

MEAN: 40.1% 2.17 (4.2%) 2.7% 32.1x 5.4x 6.4x $7.73 $1.29 57.9% 13.3x $1.02 1.9xMEDIAN: 39.8% 2.11 (0.8%) 2.4% 30.0x 5.1x 6.1x $6.87 $1.15 63.1% 11.9x $1.04 1.5x

Wachovia Securities coverage and ratings include TTEN (1), APC (3), APA (2), BR (1), DVN (3), EOG (2), EVG (1), PXD (1), PRS (1) and UCL (3).Source: Bloomberg, First Call, company data and Wachovia Securities estimates. First Call Consensus numbers are used for all EPS and CFPS estimates.

E&P Valuation Table by YTD Stock Price Performance

Wachovia Securities Master E&P Valuation Table - Sorted By YTD Stock Price PerformanceMarket Enterprise Debt To Debt Price/ Price/ EV / Total Reserve 3-Yr Avg

Stock 52-Week Cap Value Capital Per Price Performance EPS CFPS EBITDA EV / EV / Reserves % North Life F&D Costs RecycleAs of 2/28/02 (Close) Ticker Price High Low ($MM) ($MM) Ratio Boe YTD WTD 02E 02E 2002E BOE MCFE (MMBOE) Amer. Gas (Years) ($/MCFE) Ratio

Devon Energy Corporation DVN $43.68 $66.75 $30.55 $7,024.7 $14,979.2 64.3% $3.91 13.0% 3.0% 23.7x 4.4x 8.2x $7.06 $1.18 2,036.2 55.2% 9.8 $0.98 2.2xWestport Resources Corporation WRC 18.22 32.09 12.60 948.4 1,406.4 33.7% 2.77 5.0% (3.8%) NM 5.1x 5.9x 7.69 1.28 155.0 55.5% 7.7 1.03 1.5xSouthwestern Energy Company SWN 11.20 16.35 8.77 287.0 643.3 67.0% 5.62 7.7% (0.4%) 24.9x 3.7x 4.2x 6.68 1.11 63.4 87.2% 10.7 1.06 NE 3TEC Energy Corporation TTEN 15.03 21.05 11.95 227.5 346.2 38.1% 2.73 7.4% 0.6% 36.7x 5.1x 6.8x 7.89 1.31 43.5 88.5% 10.6 0.74 2.7xEnergy Partners, Ltd. EPL 8.15 14.00 5.60 219.0 244.5 13.2% 0.71 7.9% 1.2% NM 3.2x 3.5x 6.85 1.14 35.7 22.9% 9.5 0.84 2.6xEvergreen Resources, Inc. EVG 41.70 50.99 30.65 810.9 981.9 35.7% 0.98 8.0% 2.3% 51.5x 19.0x 19.4x 5.61 0.94 175.0 100.0% 32.0 0.40 3.6xApache Corporation APA 52.77 62.27 34.77 7,610.9 10,229.0 39.0% 1.82 5.8% 2.3% 20.9x 5.7x 6.4x 7.40 1.23 1,209.8 39.2% 13.3 0.90 2.2xRange Resources Corporation RRC 4.66 6.68 3.93 240.9 650.5 60.6% 4.21 2.4% (0.9%) 29.1x 2.4x 4.9x 6.48 1.08 97.3 73.3% 28.9 2.02 1.3xRemington Oil & Gas Corporation ROIL 17.71 19.49 10.03 435.5 482.1 26.5% 1.85 2.4% 0.1% 59.0x 6.2x 6.5x 19.17 3.20 25.1 58.8% 7.4 0.95 2.9xXTO Energy Inc. XTO 18.80 21.73 12.30 2,346.2 3,156.2 50.7% 2.16 7.4% 5.5% 13.1x 5.2x 6.2x 8.28 1.38 375.4 78.6% 13.7 0.64 2.0xQuicksilver Resources KWK 20.16 20.50 10.00 388.8 628.5 72.0% 2.15 5.8% 5.0% 43.8x 9.4x 9.4x 5.50 0.92 111.5 85.3% 19.8 0.54 1.8xUnit Corporation UNT 13.75 23.00 7.41 498.2 538.1 12.9% 0.99 6.6% 6.3% 17.9x 6.7x 7.0x 13.41 2.24 40.1 89.6% 10.8 0.85 2.7xKerr-McGee Corporation KMG 55.33 74.10 46.94 5,543.2 10,117.4 59.0% 3.05 1.0% 0.7% 33.1x 5.0x 5.7x 4.80 0.80 1,500.0 26.1% 13.8 1.06 1.8xPure Resources, Inc. PRS 20.00 25.30 15.00 1,032.0 1,567.2 52.3% 2.16 (0.5%) (0.5%) NM 4.8x 6.0x 6.10 1.02 247.7 64.0% 11.0 0.60 2.5xNewfield Exploration Company NFX 36.29 41.75 26.25 1,770.9 2,164.5 34.1% 2.50 2.2% 2.2% 28.6x 4.7x 5.5x 13.72 2.29 157.2 75.4% 6.8 1.48 1.4xEncore Acquisition Company EAC 13.05 17.80 11.00 391.9 455.9 19.5% 0.62 (2.0%) (1.5%) 15.7x 5.5x 6.0x 4.42 0.74 102.8 12.2% 21.8 1.08 --- Prize Energy Corp. PRZ 23.49 24.50 15.00 313.9 564.7 60.6% 2.25 1.6% 2.8% 12.8x 4.5x 6.1x 5.06 0.84 111.6 48.0% 14.9 0.56 --- Burlington Resources, Inc. BR 37.58 51.99 31.69 7,703.9 12,186.9 54.8% 2.28 0.1% 1.4% NM 6.8x 8.6x 5.63 0.94 1,968.1 75.4% 13.1 0.92 1.5xSt. Mary Land & Exploration Company MARY 21.70 25.88 14.58 613.1 627.4 4.8% 0.24 2.4% 3.8% 44.3x 6.3x 6.4x 10.65 1.77 58.6 64.3% 6.7 1.11 1.5xPioneer Natural Resources Company PXD 19.82 23.05 12.62 1,972.5 3,527.1 56.8% 2.32 2.9% 4.4% 38.1x 5.2x 6.9x 5.22 0.87 671.4 48.3% 15.4 0.58 1.8xUnocal Corporation UCL 35.95 40.00 29.51 8,792.1 11,642.1 47.1% 1.57 (0.3%) 1.2% 31.3x 5.3x 5.5x 5.62 0.94 1,814.1 19.0% 9.5 1.24 0.9xMurphy Oil Corporation MUR 86.18 87.85 60.75 3,937.0 4,466.9 26.2% 1.20 2.5% 4.1% 36.2x 7.4x 7.7x 10.00 1.67 442.3 25.0% 11.7 0.87 2.4xTom Brown, Inc. TMBR 27.56 36.75 19.65 1,104.6 1,202.4 14.4% 0.87 2.0% 4.0% NM 8.8x 8.3x 9.84 1.64 113.0 87.6% 10.9 0.87 1.9xPlains Resources Inc. PLX 22.48 29.50 19.00 589.6 868.3 53.9% 1.17 (8.7%) (6.8%) 13.7x 5.8x 6.4x 3.43 0.57 238.7 6.5% 26.9 0.41 1.3xPatina Oil & Gas Corporation POG 27.20 33.80 20.99 616.7 704.4 24.9% 0.73 (1.1%) 1.9% 14.6x 5.3x 5.8x 5.86 0.98 119.9 73.2% 16.5 0.25 6.7xNoble Affiliates, Inc. NBL 36.20 51.09 27.50 2,069.6 2,705.2 38.1% 1.61 2.6% 6.0% NM 4.7x 5.4x 6.56 1.09 394.5 31.8% 11.5 1.28 1.4xPenn Virginia Corporation PVA 36.10 45.40 26.03 325.2 460.2 39.3% 3.46 5.9% 9.9% NM NE NE 10.46 1.74 39.0 88.4% 19.8 1.08 NE

Pogo Producing Company PPP 26.92 34.50 20.45 1,628.1 2,385.1 47.6% 2.54 2.5% 6.8% 41.4x 4.3x 5.9x 7.95 1.33 298.2 32.9% 14.8 1.21 1.0xSpinnaker Exploration Company SKE 41.02 48.00 30.00 1,162.3 1,162.3 0.0% --- (0.3%) 4.3% 31.8x 7.8x 7.1x 20.61 3.43 51.2 72.7% 10.2 1.69 1.7xPetroQuest Energy, Inc. PQUE 4.98 8.99 3.95 197.7 207.7 15.8% 0.73 (6.4%) (1.8%) NM 6.1x 5.8x 15.04 2.51 13.7 54.9% 16.7 1.33 1.5xEquitable Resources, Inc. EQT 32.68 40.50 26.00 2,142.6 2,684.8 39.3% 1.47 (4.1%) 1.4% 13.6x NE NE 6.62 1.10 367.6 98.1% 24.5 0.71 NE Denbury Resources Inc. DNR 7.05 12.30 5.84 374.7 489.3 24.4% 1.14 (3.6%) 2.5% 54.2x 3.8x 3.9x 4.86 0.81 100.6 28.5% 12.9 1.08 1.3xPrima Energy Corporation PENG 21.74 37.00 19.10 286.8 286.8 0.0% --- (0.0%) 8.1% 32.9x 10.8x 10.4x 9.42 1.57 29.4 87.3% 15.6 0.54 4.2xKey Production Company, Inc. KP 16.68 24.70 10.85 236.2 271.2 17.4% 1.36 (1.9%) 6.6% 21.4x 5.1x 5.6x 10.57 1.76 25.6 63.8% 6.7 1.60 1.4xOcean Energy, Inc. OEI 18.35 21.72 14.00 3,287.3 4,624.9 48.1% 2.23 (4.4%) 3.9% 31.6x 6.3x 7.7x 7.42 1.24 600.8 43.8% 12.1 1.03 1.4xNuevo Energy Company NEV 13.75 21.56 11.10 232.1 641.6 63.0% 1.65 (8.3%) 0.0% NM 2.9x 5.1x 2.50 0.42 247.6 11.2% 12.4 0.75 0.5xComstock Resources, Inc. CRK 6.60 13.15 4.95 224.2 448.2 52.4% 3.07 (5.7%) 3.1% 82.5x 2.9x 4.6x 6.64 1.11 67.1 73.9% 10.6 1.18 1.5xBerry Petroleum Company BRY 13.30 17.75 11.00 295.3 328.3 18.1% 0.31 (15.3%) (6.8%) 12.1x 6.0x 6.2x 3.05 0.51 107.4 0.6% 19.6 0.65 1.8xAnadarko Petroleum APC 52.10 73.00 43.00 13,025.0 17,854.0 39.9% 2.05 (8.4%) 2.9% 25.9x 7.9x 10.4x 7.76 1.29 2,132.7 49.9% 11.2 1.05 1.8xStone Energy Corporation SGY 36.87 59.40 29.66 965.4 1,065.4 11.3% 1.50 (6.7%) 4.9% 20.4x 4.0x 4.3x 15.82 2.64 66.7 68.0% 6.3 1.54 1.4xChesapeake Energy Corporation CHK 6.27 11.06 4.50 1,068.3 2,336.7 67.4% 4.35 (5.1%) 6.6% 17.9x 3.2x 5.3x 7.75 1.29 291.7 91.0% 13.0 1.05 1.3xMagnum Hunter Resources, Inc. MHR 7.51 13.90 6.65 276.4 542.5 69.3% 4.35 (9.5%) 1.9% 32.7x 4.2x 6.1x 8.71 1.45 61.2 63.5% 13.4 1.26 2.0xHouston Exploration Company THX 31.25 38.00 22.20 961.5 1,121.5 22.1% 1.71 (6.9%) 5.5% 30.0x 3.9x 4.5x 11.87 1.98 93.6 94.3% 7.0 1.43 1.4xForest Oil Corporation FST 25.69 37.85 22.75 1,245.3 1,901.1 40.4% 2.85 (8.9%) 3.3% NM 6.2x 7.6x 8.27 1.38 229.9 61.2% 7.6 1.16 1.3xEOG Resources, Inc. EOG 35.19 50.70 25.80 4,122.2 4,970.7 35.5% 0.99 (10.0%) 3.4% 73.3x 6.4x 7.2x 7.05 1.18 704.9 62.7% 10.4 0.97 1.7xThe Meridian Resource Corporation TMR 3.43 8.60 2.65 185.3 375.3 50.4% 3.72 (14.0%) (0.6%) 22.9x 2.3x 3.8x 7.16 1.19 51.1 56.3% 5.9 1.94 1.0xCabot Oil & Gas Corporation COG 20.10 34.35 16.25 623.1 990.1 50.1% 1.86 (16.4%) 1.8% NM 4.9x 6.8x 5.01 0.84 197.5 89.1% 17.7 1.12 1.3xAbraxas Petroleum Corporation ABP 1.05 5.38 0.64 31.7 302.8 NM 6.66 (20.5%) 1.9% NM 8.1x 6.7x 5.96 0.99 40.7 78.3% 9.5 1.91 0.2xMission Resources Corporation MSSN 2.80 9.55 2.55 66.3 332.1 65.9% 3.38 (20.0%) 2.6% NM 2.2x 5.9x 4.09 0.68 78.5 32.0% 10.4 --- --- Clayton Williams Energy, Inc. CWEI 9.61 22.35 8.10 90.4 147.4 39.0% 3.23 (26.6%) (5.2%) NM 1.9x 2.4x 6.90 1.15 17.6 26.8% 4.7 1.51 1.4xSwift Energy Company SFY 17.81 37.70 15.39 453.4 703.9 39.8% 2.39 (11.8%) 14.0% 52.4x 6.0x 7.8x 6.62 1.10 104.9 66.5% 15.0 1.54 1.4xCallon Petroleum Company CPE 4.35 13.49 3.96 58.3 232.0 52.9% 3.12 (36.5%) (4.2%) NM 3.7x 7.5x 4.03 0.67 55.6 40.0% 21.8 0.75 2.2xVintage Petroleum, Inc. VPI 10.50 22.45 7.85 672.7 1,689.1 58.1% 2.08 (27.3%) 21.1% NM 3.7x 5.8x 3.11 0.52 489.1 14.9% 17.0 0.44 2.8xATP Oil & Gas Corporation ATPG 1.70 14.13 1.47 34.5 114.6 59.5% 2.29 (43.0%) 1.2% NM 0.8x 2.2x 3.25 0.54 35.0 85.0% 8.6 1.26 1.2x

MEAN: 40.1% 2.17 (4.2%) 2.7% 32.1x 5.4x 6.4x $7.73 $1.29 57.9% 13.3x $1.02 1.9xMEDIAN: 39.8% 2.11 (0.8%) 2.4% 30.0x 5.1x 6.1x $6.87 $1.15 63.1% 11.9x $1.04 1.5x

Wachovia Securities coverage and ratings include TTEN (1), APC (3), APA (2), BR (1), DVN (3), EOG (2), EVG (1), PXD (1), PRS (1) and UCL (3). S&P 500 Index performance is 0.0% YTD and 0.0% WOW.Source: Bloomberg, First Call, company data and Wachovia Securities estimates. First Call Consensus numbers are used for all EPS and CFPS estimates.

Investment Considerations

Stock price February 22, 2002 $1.68

Stock price to cash flow 0 .7X

Stock price to proved reserves $0.14 / mcfe

Recipient of numerous oil & gas industry and business awards

Oil & Gas World 1999 Best Field Improvement

Gulf of Mexico

T. Paul BulmahnEntrepreneur of Year 2000Energy & Energy Services

Ernst & Young

Financial Times of London2000 Finalist: Best Oil and Gas Company

2000 Inc./CiscoGrowing with Technology Award

Inc. 5003 Consecutive Years

1999-2001Fastest Growing Energy Company

Each Year

NASDAQ: ATPGATP Oil & Gas Corporation

4600 Post Oak Place, Suite 200Houston, TX 77027-9726

713-622-3311www.atpog.com