Monell Unit CO2 Flood Patrick Draw Field Sweetwater County, Wyoming

May 29th, 2008

Prepared by: Jason GainesSenior Reservoir Engineer

APC Forward Looking StatementThis presentation contains forwardThis presentation contains forward--looking statements within looking statements within the meaning of Section 27A of the Securities Act of 1933 and the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Anadarko Section 21E of the Securities Exchange Act of 1934. Anadarko believes that its expectations are based on reasonable believes that its expectations are based on reasonable assumptions. No assurance, however, can be given that such assumptions. No assurance, however, can be given that such expectations will prove to have been correct. A number of expectations will prove to have been correct. A number of factors could cause actual results to differ materially from thefactors could cause actual results to differ materially from the projections, anticipated results or other expectations projections, anticipated results or other expectations expressed in this presentation. Anadarko cannot guarantee expressed in this presentation. Anadarko cannot guarantee that it will successfully execute on its exploration, drilling athat it will successfully execute on its exploration, drilling and nd development plans. See development plans. See ““Risk FactorsRisk Factors”” in the companyin the company’’s 2007 s 2007 Annual Report on Form 10Annual Report on Form 10--K and other public filings and press K and other public filings and press releases. Anadarko undertakes no obligation to publicly releases. Anadarko undertakes no obligation to publicly update or revise any forwardupdate or revise any forward--looking statements.looking statements.

Fields– Monell– Salt Creek– Sussex

Pipelines– 33 mile, 8”– 125 mile, 16”

CO2 Supply– XOM Shute

Creek

Anadarko’s Wyoming EOR Assets

Salt Creek

Monell

Sussex

16”

8”

Land GrantGas FieldsOil FieldsThird Party CO2 PipelineAPC CO2 Pipeline

Monell Overview

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31

25262728

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FEET

0 2,963

Active

Ph3

Future

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25262728

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Active

Ph3

Future

General Facts & History– Discovered in 1959– ~115 MMBOOIP (prod 40 MMBO)– 2001: Initiated pilot– 2003: 33 mile PL & 1st CO2 injection– 2006: Ph2 start-up– 2007: NGL plant commissioned– 2008: 9-spot drlg program ( 9 wells )– 2009: Ph3 development– Planned sequestration of 85 Bcf CO2

Current Status– 3,000 BOPD– 48 MMCFD CO2 injection– 39 CO2 injectors– CO2 -EOR cumulative of 3 MMBO

Upper Cretacous Stratigraphy Lance Formation Fox Hills Sandstone Lewis Shale Almond Formation Ericson Sandstone Rock Springs Fm

Upp

er C

reta

ceou

s

Blair Fm

Mes

aver

de G

roup

West-East Cross Section

Fort UnionLanceLewis

Almond

NormalFault

SeaLevel

Patrick Draw Field Table Rock

Wasatchft

2000

mi0 1 2

Monell Unit – Upper Almond Reservoir

UA-5A Pay

UA-5B Pay

Lewis Shale

Lower Almond

MONELL UNIT

49

4500

4550

-90 10SPNORM

500 0CILD

0 100ILD

0 100SN

0 40MINV

0 40MNOR

Monell Unit Type Log

Reservoir HighlightsCretaceous Mesaverde Almond SS stratigraphic trap

Barrier island/tidal channel inlet/shoreface depositional system

Very fine to fine-grained lithic, illitic, kaolinitic, and quartzose sandstones

20% Porosity, 30md Permeability, 40% Swi

5 deg. dip, 25’ Net Pay, 5,000 Acres at 4,500’ depth

Fractures and faulting are minor

Oil zone confined up-dip by the depleted low pressure gas cap and down-dip by permeability pinchout

~115 MMSTB OOIP, 500 GOR, 43 deg. API sweet

20% Primary RF, 14% Waterflood RF

1,800 psi original reservoir pressure at 120 deg.F

CO2 Miscible with Oil (1450# MMP)

Monell Unit – Phase Development

Phase 1Phase 1

Phase 2Phase 2

Development HighlightsPhase 1 implemented adding first 28 patterns of development

“Water curtain” concept proven up as affective pressure barrier– Horizontal 1: MU 43-27H - 5,000’ lateral water injection well

– Horizontal 2: MU 44-27H - 6,800’ lateral water injection well

– Four vertical water injection wells to the north

Flood response seen within 3 months of initial injection

Phase 2 implementation added 12 patterns of development– Applied lessons learned from Phase 1 to Phase 2

• Drilling, Completions, Facilities

NGL plant installed and processing recycled CO2 to recover NGL’s

Monitor/idle wellbores converted to producers to test 9-spot concept

Drilling campaign under way to test 9-spot pattern performance

Future phase development planning currently under way

Operations HighlightsDrilling

– Currently drilling with coiled tubing drill rig

Completions– 50/50 lease crude and diesel frac fluid

Wellbores– Injectors: 5-1/2” casing; 2-3/8” IC tubing; Ni coated packer; inconell tubing hanger

– Producers:

• Pumping: 5-1/2” csg; 2-7/8” CS tubing; continuous sucker rod; 456 PU

• Flowing: 5-1/2” csg; 2-3/8” IC tubing; Ni coated packer; inconell tubing hanger;

H20 slip-stream line at wellhead

Flowlines– Injection/Production: Continuous HDPE

Headers– Latest design (A2) includes central injection/production manifolds in common facility

Operations Highlights

Operations Highlights

Operations Highlights

Operations Highlights

Operations Highlights

Operations Highlights

Operations Highlights

Operations Highlights

Monell Unit Performance

PATRICK DRAW FIELD, MONELL UNITCO2 FLOOD PROJECT PERFORMANCE

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Sep-

59

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BPD

, MC

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Oil Gas CO2 Inj

Monell Unit – Production History

Primary Secondary Tertiary CO2 Flood

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10

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1,000

10,000

100,000

Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08 Jan-09

BPD

, MC

FD

Oil Production History

CO2 Inj History

Monell Unit Performance

3,000 bopd3,000 bopd

48 MMcfdi48 MMcfdi

Pilot 2001-02

1st CO2 Inj Sept.03

Pilot 2001-02

1st CO2 Inj Sept.03

Monell 9-Spot Review

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50

100

150

200

250

1 135 269 403 537 671 805 939 1073 1207 1341 1475 1609 1743

Normalized Time (days)

BOPD

#6Well#7 Well#14 Well#17 Well#18 Well#121Well#157WellType Well

Monell Unit – 9-Spot Type Well

Oil Production

Monell Unit – 9-Spot Drilling - 2008

Monell Unit – Future Development

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Ph3

Future

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0 2,963

Active

Ph3

Future

Ph1

Ph2

Monell Unit – Applied ToolsField/Pattern surveillance (OFM)

Dimensionless curves developed to help forecast performance– Allows pattern comparison and balancing

– Will help identify problem patterns

Bottom Hole Pressure Tool – Surface Injection Pressure– Calculates BHIP from SIP using phase envelope P & T segments

– Assures that we remain below fracture pressure at all times

CO2 Injection Schedule – Developed to aid in balancing patterns and CO2 utilization

– Automated system that can be controlled by volume and/or pressure

Production Allocation Tool– Ensure that production is allocated correctly from well test data

Reservoir Simulation – History Matching

RF_for_PI_II PATTERN: Phase 1&2 Patt_11-35PATTERN: Phase 1&2 Patt_13-25PATTERN: Phase 1&2 Patt_13-35PATTERN: Phase 1&2 Patt_15-25PATTERN: Phase 1&2 Patt_22-2PATTERN: Phase 1&2 Patt_22-25PATTERN: Phase 1&2 Patt_22-26PATTERN: Phase 1&2 Patt_22-3PATTERN: Phase 1&2 Patt_22-35PATTERN: Phase 1&2 Patt_22-36PATTERN: Phase 1&2 Patt_24-25PATTERN: Phase 1&2 Patt_24-26PATTERN: Phase 1&2 Patt_24-3PATTERN: Phase 1&2 Patt_24-35PATTERN: Phase 1&2 Patt_31-3PATTERN: Phase 1&2 Patt_31-35PATTERN: Phase 1&2 Patt_33-25PATTERN: Phase 1&2 Patt_33-26PATTERN: Phase 1&2 Patt_33-3PATTERN: Phase 1&2 Patt_33-34PATTERN: Phase 1&2 Patt_33-35PATTERN: Phase 1&2 Patt_35-25PATTERN: Phase 1&2 Patt_35-3PATTERN: Phase 1&2 Patt_35-35PATTERN: Phase 1&2 Patt_42-25PATTERN: Phase 1&2 Patt_42-26PATTERN: Phase 1&2 Patt_42-3PATTERN: Phase 1&2 Patt_42-34PATTERN: Phase 1&2 Patt_42-35PATTERN: Phase 1&2 Patt_44-25PATTERN: Phase 1&2 Patt_44-26PATTERN: Phase 1&2 Patt_44-3PATTERN: Phase 1&2 Patt_44-34PATTERN: Phase 1&2 Patt_44-35PATTERN: Phase 1&2 Patt_51-3PATTERN: Phase 1&2 Patt_53-25PATTERN: Phase 1&2 Patt_53-27PATTERN: Phase 1&2 Patt_53-3PATTERN: Phase 1&2 Patt_53-35

Monell Unit – Applied ToolsR

ecov

ery

Fact

or

Rec

over

y Fa

ctor

HCPVinjHCPVinj2003 04 05 06 07 08

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Patt_24-26Daily Oil Rate ( bbl/d ) Daily Gas Rate ( Mcf/d ) Daily Water Rate ( bbl/d ) Daily CO2 Volume ( Mcf ) PDB Daily Prd CO2 Volume ( Mcf/d ) RatioGORCO2d ( Mcf/bbl )

Anadarko Petroleum CompanyPATTERN: Patt_24-26

Monell Unit – Applied Tools

2003 04 05 06 07 080.1

0.5

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MONELL UN 31-35 Daily Inj Water Volume ( bbl ) Daily CO2 Volume ( Mcf )

Anadarko Petroleum CorporationMONELL UN 31-35

Well Name:

Well Depth SIP SIT4,597 1,698 75

Tgrad0.00 F/ft

Depth Temp Davg Depth Pressure0 75 0 0 1,698

460 75 229.85 460 1,870919 75 689.55 919 2,044

1379 75 1149.25 1,379 2,2201839 75 1608.95 1,839 2,3992299 75 2068.65 2,299 2,5792758 75 2528.35 2,758 2,7613218 75 2988.05 3,218 2,9453678 75 3447.75 3,678 3,1304137 75 3907.45 4,137 3,3164597 75 4367.15 4,597 3,5035057 4826.85

0.76 psi/ft

Rate1,749 mcfd

Date Stamp02.04.08

Monell Unit 31-35

Bottom Hole Pressure

3,503

0

500

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1,500

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5,000

0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000Monell Unit 31-35

Monell Unit 31-35

Well Name:

Well Depth SIP SIT4,597 750 75

Tgrad0.00 F/ft

Depth Temp Davg Depth Pressure0 75 0 0 750

460 75 229.85 460 780919 75 689.55 919 813

1379 75 1149.25 1,379 8501839 75 1608.95 1,839 9502299 75 2068.65 2,299 1,1022758 75 2528.35 2,758 1,2623218 75 2988.05 3,218 1,4253678 75 3447.75 3,678 1,5934137 75 3907.45 4,137 1,7634597 75 4367.15 4,597 1,9335057 4826.85

0.42 psi/ft

Rate

Date Stamp

Monell Unit 31-35

Bottom Hole Pressure

1,933

0

500

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2,500

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3,500

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4,500

5,000

0 500 1,000 1,500 2,000 2,500Monell Unit 31-35

Monell Unit 31-35

Monell Unit – CO2 In ActionPATRICK DRAW FIELD, MONELL UNIT

CO2 FLOOD PROJECT PERFORMANCE

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10

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100000

Sep-

59

Sep-

61

Sep-

63

Sep-

65

Sep-

67

Sep-

69

Sep-

71

Sep-

73

Sep-

75

Sep-

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Oil Gas CO2 Inj

Primary Secondary Tertiary CO2 Flood

Salt Creek OverviewGeneral Facts & History– Discovered in late 1800’s– ~1.7 Bbbl OOIP (0.7 Bbbl cum prod)– 9 productive intervals & 4,400 total wells– 2003: Completed pilot, Ph1 & 125 mile PL– 2004: 1st CO2 injection– 2005: Ph2 start-up– 2007: Ph3-4 start-up– 2008: 2Q Ph5 start-up– Flowing producers – identical inj/prod set-up– Planned sequestration of 660 Bcf CO2

Current Status– 7,000 BOPD from CO2 ( 8,500 BOPD total )– 320 MMCFD CO2 injection– 153 CO2 WAG injectors ( 20-acre 5-spots )– CO2 -EOR cumulative of 5.5 MMBO

161718

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282930

456

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131415

2

22 23 24

252627

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161718

19 20 21

282930

31 32 33

78 910 11 12

131415

22 23 24

252627

34 35 36

SALT CREEKLIGHT OIL UNIT

SALT CREEKSOUTH UNIT

Town ofMidwestTown ofMidwest

Ph1-2

Ph3-4

Ph5

Ph6

Ph7

Scale = 1 mile

Future Development

161718

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282930

456

7 8 9

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131415

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22 23 24

252627

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19 20 21

282930

31 32 33

78 910 11 12

131415

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252627

34 35 36

SALT CREEKLIGHT OIL UNIT

SALT CREEKSOUTH UNIT

Town ofMidwestTown ofMidwest

Ph1-2

Ph3-4

Ph5

Ph6

Ph7

Scale = 1 mile

Future Development

Phase 1-4 CO2 Flood Performance

Salt Creek Phases 1-4 CO2 Flood Performance

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9,000

Jan-04 Jul-04 Jan-05 Jul-05 Jan-06 Jul-06 Jan-07 Jul-07 Jan-08

Gro

ss O

il P

rodu

ctio

n (B

OP

D)

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Tota

l CO

2 In

ject

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(MM

CFD

)

Oil Production

CO2 Injection

Anadarko’s Rockies EORCurrent ActivityMonell Unit 3,000 BOPD 50% Developed (based on area)

Improved sweep via 9-spot pilotFive years of continuous injection without major breakthrough

Salt Creek 7,000 BOPD 20% Developed (based on area)Unique CO2 flood pushing technological envelopePhase development allows flexibility to apply lessons learned

Future Development1) Significant undeveloped resources at Monell and Salt Creek2) Linch Fields ~ 15 miles north of Salt Creek3) Apply lessons learned to future developments

Discussion?