www.anadarko.com | NYSE: APC

ANADARKO PETROLEUM CORPORATION

INVESTOR RELATIONS CONTACTS: John Colglazier Vice President 832/636-2306 Dean Hennings Doug Lawler Manager 832/636-2462 Vice President, Operations Wayne Rodrigs Manager 832/636-2305 May 25, 2011 www.anadarko.com | NYSE: APC Cautionary Language Regarding Forward-Looking Statements and Other Matters

This presentation contains 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. The words “believe,” “expect,” “plan” or other similar expressions are intended to identify forward-looking statements. These forward-looking statements are based upon Anadarko’s current expectations and beliefs concerning future developments and their potential impact thereon. While Anadarko believes that its expectations are based on reasonable assumptions as and when made, no assurance can be given that such expectations will prove to have been correct. A number of factors could cause actual results to differ materially from the projections, anticipated results or other expectations expressed in this presentation, including the following: Anadarko's ability to successfully drill, complete, test and produce the wells and prospects identified in this presentation; to meet financial and operating guidance; to execute the 2011 capital program and meet the long-term goals identified in this presentation; the outcome of events in the Gulf of Mexico relating to the Deepwater Horizon event and the Company’s ability to successfully defend its stated position under the corresponding Operating Agreement; the legislative and regulatory changes, such as delays in the processing and approval of drilling permits, exploration plans andoil spill response plans, that may impact the Company’s Gulf of Mexico and International offshore operations resulting from the Deepwater Horizon event. Other factors that could impact the forward-looking statements are described in “Risk Factors” in the company’s 2010 Annual Report on Form 10-K, Quarterly Reports on Form 10-Q for the quarter ended March 31,2011 and other public filings and press releases. Readers are cautioned not to place undue reliance on forward-looking statements, which speak as of the date hereof. Anadarko undertakes no obligation to publicly update or revise any forward-looking statements. Please also see our Web site at www.anadarko.com under “Investor Relations” for reconciliations of the differences between any non-GAAP measures used in this presentation and the most directly comparable GAAP financial measures. Cautionary Note to U.S. Investors — Effective January 1, 2010, the U.S. Securities and Exchange Commission (SEC) permits oil and gas companies, in their filings with the SEC, to disclose only proved, probable and possible reserves that meet the SEC’s definitions for such terms. We may use terms in this presentation, such as “resources,” “net resources,” “net discovered resources,” “net risked resources,” “net lower-risked captured resources,” “net risked captured resources,” “gross resources,” “gross resource potential,”

“gross unrisked resource potential,” “gross unrisked resources,” and similar terms that the SEC’s guidelines strictly prohibit us from including in filings with the SEC. U.S. Investors are urged to consider closely the oil and gas disclosures in our Form 10-K for the year ended December 31, 2010, File No. 001-08968, available from us at www.anadarko.com or by writing us at: Anadarko Petroleum

Corporation, 1201 Lake Robbins Drive, The Woodlands, Texas 77380 Attn: Investor Relations. You can also obtain this form from the SEC by calling 1-800-SEC-0330.

2 www.anadarko.com | NYSE: APC Our Premier Balanced Portfolio is Built to Deliver Our Strategy is Working: Identify and Commercialize Resources Explore in High-Potential, Proven Basins Employ a Global Business Development Approach Ensure Financial Discipline and Flexibility

PRODUCTIONPRODUCTION EXPLORATIONEXPLORATION

3 www.anadarko.com | NYSE: APC Built for Sustainable Growth and Value 11+ BBOE 10.5+ BBOE De-Risked ExplorationExploration Mozambique Accelerate Production ExplorationExploration 3.5+3.5+ BBOEBBOE 3.5+3.5+ BBOEBBOE West Africa and Reserves Growth Shales Brazil D e-R Allocate Capital with is ke d S NAV Focus ha les Capitalize Upon DevelopmentDevelopment DevelopmentDevelopment Portfolio Optionality 5+5+ BBOEBBOE 5.5+5.5+ BBOEBBOE

BaseBase AssetsAssets BaseBase AssetsAssets 2.32.3 BBOEBBOE 2.42.4 BBOEBBOE

March 2010 February 2011

4 www.anadarko.com | NYSE: APC Predictable Reserves Generator

Capital-Efficient Base More Than Replaces Production Mega Projects and Shales Accelerate Reserves Growth

3+ BBOE of Proved Reserves by Year-End 2014 4 3+ BBOE

2.4 BBOE

2 BBOE

0 YE 2010 Production Base Mega Shales YE 2014E Projects

5 www.anadarko.com | NYSE: APC Line-of-Sight Production Growth

7 - 9% Five-Year Production CAGR Moving Toward Equalized Product Mix

1,000 50%

R CCAAGGR 800 77 -- 99%%

45% 600 Percent Liquids Sales Volumes (MBOE/d) Volumes Sales

400 40% 2010 2011E 2012E 2013E 2014E

Base Shales Megas Percent Liquids

6 www.anadarko.com | NYSE: APC Mega Projects Deliver Differentiating Value 400 Estimates Based on $90/Bbl and $4.50/Mcf Significant Oil Volumes and Reserves Robust Economics and Margins

World-Class Projects with Optionality (MBOE/d) Volumes Sales 0 2011E 2012E 2013E 2014E 2015E 2016E 2017E 2018E 10 CAPEX EBITDAX Megas Emerging Megas Megas Emerging Megas

AX 5 ITD EB nal otio

$ Billions $ N

Notional CAPEX 0 2008 2009 2010 2011E 2012E 201 3E 2014E 2015E 2016E 2017E 2018E Notional Estimates Assume No Monetizations 7 www.anadarko.com | NYSE: APC 2011 Expectations Guidance Sales Volumes (MMBOE) 244 - 248 Capital* (Billions) $6.2 - $6.6 Reserve Replacement 150+%

By Area By Type

Midstream/ Midstream/ Other Other 20% 20% Near-Term Base 35% GOM U.S. Onshore 10% 45% Exploration 20% Int’l/Frontier Mega Shales 25% Projects 10% 15%

2011 Capital *Excludes Western Gas Partners, LP (WES)

8 www.anadarko.com | NYSE: APC Strength of Balance Sheet

Ended 1Q11 with ~$3.5 Billion of Cash on Hand

Access to 5-Year $5 Billion Undrawn Credit Facility

Generated Free Cash Flow in 1Q11

9 www.anadarko.com | NYSE: APC Capital-Efficient U.S. Onshore Portfolio

Base Assets Accelerating Value From Shales 25+ Tcfe Resource Base Premier Acreage Position Scaleable Programs Production and Reserves Enhancing Margins and Growth Engine Efficiencies

MARCELLUS 6+ Tcf Net Risked Resources Net Acreage: ~15 Million POWDER RIVER GREEN RIVER NIOBRARA WATTENBERG HAYNESVILLE GNB HBP Acreage BOSSIER CARTHAGE PERMIAN CHALK SHALE PLAY NATURAL GAS EAGLEFORD/PEARSALL ~350 MMBOE Net Risked Resources OIL AND GAS

10 www.anadarko.com | NYSE: APC Tremendous Shales Growth

~10% of Total Company Sales Volumes at Year-End 2011 Significant Reserves Growth Engine Robust Economics Shales and Growth Plays 80 ST CA RE FO 60 GR CA % C 0+ EAGLEFORD 10 40

MARCELLUS 20 Sales Volumes (MBOE/d) HAYNESVILLE 0 BONE SPRING 2010 2011E 11 www.anadarko.com | NYSE: APC Eagleford: Stellar Growth

450+ MBOE Average EUR Gross Acreage: ~400,000 2,000+ Identified Drill Sites TXTX Net Acreage: ~200,000 Infrastructure Backbone in Place

2011 Planned Activity Concentrated in Drill 200+ Wells Condensate-Rich Window Prudently Paced Development with Joint Venture

Sales-Volumes Mix

27% Oil 46% 0 10 Gas Miles 27% NGLs APC ACREAGE ACTIVE APC DEVELOPMENT

12 www.anadarko.com | NYSE: APC Marcellus Shale Growth Engine

MarcellusMarcellus ShaleShale PlayPlay Significant Outperformance 1+ BBOE Net Risked Resources NEW YORK Gross Acreage: ~760,000 PENNSYLVANIA Improving Average EURs PENNSYLVANIA Net Acreage: ~260,000 PENNSYLVANIA 2011 Planned Activity 10+ Operated Rigs Infrastructure Expansion

CHESAPEAKE OPERATED 8 Average Marcellus Production 7 (~80 Wells) 6 6 Bcf EUR 5 ANADARKO OPERATED 4 APC Average

MMcf/d 3 Gu idance Type C 2 4 Bcf EUR urve

1 0 20 Miles 0 0 50 100 150 200 250 300 APC ACREAGE 2011 FOCUS AREA Days 13 www.anadarko.com | NYSE: APC Jubilee: First Oil Achieved in 3.5 Years World-Class Development in Record Time

Gross Acreage: ~0.6 Million Unit WI: 23.5%

JUBILEE Operator Resource Range of 600 - 1,500 MMBOE First Oil December 2010 On Time, On Budget Ramping to 120,000 BOPD DEEPWATER TANO MAHOGANY EAST (WI 18%) High-Quality Development Outstanding Reservoir Characteristics 0 5 WEST CAPE THREE POINTS MILES (WI 31%) Light Oil

ANADARKO WI BLOCKS WATER INJECTOR High Flow Rates DISCOVERY FIELD GAS INJECTOR OIL PRODUCER SUCCESSFUL WELLS

May 2007 June 2008 1st Half 2009 Q3 2009 2009 - 2010 Q4 2010 Discovery Appraisal Successful Project Construction, Installation, First Drilling Flow Tests Sanction Drilling and Completions Production 14 www.anadarko.com | NYSE: APC Our Big Boys are BIG

1+ BBOE Net Risked Resources

Gross Resource Potential in MMBOE Itaipu Wahoo 200+200+ 300+300+ Moz. Gas Vito 200+200+ Jubilee Heidelberg 200+200+ 300+300+ El Merk 6+6+ TcfTcf 600-1,500600-1,500 Lucius 500-600500-600 Tweneboa 300+300+ 300+300+ Enyenra Caesar/Tonga 200-400200-400 Dev Cost / BOE

Prior 2007 2008 2009 2010 Discovery Year

15 www.anadarko.com | NYSE: APC Creating Value Through Exploration 2004 - 2010 Net Risked Resources Discovered: 3.5 BBOE

Exploration Capital Spent: ~$6 Billion Exploration Monetization: ~$8 Billion

TransitionedTransitioned toto ToTo BeBe AppraisedAppraised AppraisingAppraising SanctionedSanctioned ProducingProducing DevelopmentDevelopment Heidelberg Vito Shenandoah Wahoo Lucius Caesar/ Shales Itauna Itaipu Mahogany E. Tonga Jubilee Mercury Tweneboa El Merk Badik Enyenra Teak Moz. Gas

GULF OF MEXICO INTERNATIONAL U.S. ONSHORE

16 www.anadarko.com | NYSE: APC Focused Exploration in High-Potential Basins Deliver 500+ MMBOE of Net Risked Resources ~25 High-Impact Deepwater Exploration / Appraisal Wells Deep, Multi-Year Inventory of Identified Prospects

SOUTHEAST ASIA WEST AFRICA •~6MM Gross Acres •~7MM Gross Acres •1 Exploration Well •12-15 Exploration & Appraisal Wells

GULF OF MEXICO NEW ZEALAND •~3MM Gross Acres •~17MM Gross Acres •3-6 Exploration & Appraisal Wells •~1 Exploration Well

EAST AFRICA BRAZIL •~14MM Gross Acres •~1MM Gross Acres •3-5 Exploration & Appraisal Wells •3 Appraisal Wells

Planned 2011 Activity 17 www.anadarko.com | NYSE: APC Ghana: Line of Sight to Next Development

Jubilee Producing Gross Acreage: ~0.6 MM 4 Additional Major Discoveries TWENEBOA #2 OWO & TEAK #2 Mahogany East Successful DST Discovery BANDA #1 Sidetrack TEAK #1 Tweneboa TWENEBOA #4 TWENEBOA #3 Discovery Drilling Successful Successful Teak Appraisal Appraisal Assin Enyenra Odum ENYENRA #2A Teak Successful Jubilee Banda & Appraisal Banda Deep

Tweneboa Transition Discoveries Turonian Mahogany Deep East Dahoma Updip Makore to Development DEEPWATER TANO (APC WI 18%) 2011 Planned Activity WEST CAPE THREE PROSPECT POINTS Drill 4+ Exploration Wells DISCOVERY (APC WI 31%) SUCCESSFUL WELL 0 10 Drill 4+ Appraisal Wells 2011 PLANNED DRILLING Miles Conduct DSTs

18 www.anadarko.com | NYSE: APC Actively Evaluating Sierra Leone and Liberia

ANADARKO WI BLOCK 2011 Planned Activity SUCCESSFUL WELL DISCOVERY Drill 2 Exploration Wells 2011 PLANNED DRILLING CAMPANIAN Drill Mercury Appraisal Well Gross Acreage: ~5 MM LOWER CAMPANIAN-TURONIAN SIERRA JUBILEE Perform DST VENUS B #1 LEONE GHANA JUBILEE Discovery UNUNITIT MERCURY #1 Discovery LIBERIA SL-07B-10 LB-17 DEEPWATER TANO WEST CAPE JUPITER LB-16 THREE POINTS MERCURY #2 LB-15 (To Scale)

MONTSERRADO/ KEBAWANA IO JUPITER MERCURY STRONTIUM YEKEPA MONTSERRADO #1 MONTSERRADO DEEP Sierra Leone Liberia

~900 mi223D ~900 mi 3D LB-10 inin ProgressProgress

Source Rock 0 40 110 Miles Miles

19 www.anadarko.com | NYSE: APC Offshore Mozambique Success Story Gross Acreage: ~2.6 MM 4 Major Discoveries Lagosta Barquentine WINDJAMMER BARQUENTINE Discovery Discovery Windjammer Tubarão

LAGOSTA #1 2011 Planned Activity Dedicated Rig for Appraisals LAGOSTA Add Second Rig in Q4 Discovery Expand 3D Seismic TUBARÃO Discovery Robust Exploration Inventory

APC Operator OFFSHORE AREA 1 (APC WI 36.5%) ANADARKO WI BLOCK GAS DISCOVERY PROSPECTS AND LEADS 0 15 EXISTING 3D SEISMIC Miles 2011 3D SEISMIC

20 www.anadarko.com | NYSE: APC Brazil: Appraising Success Gross Acreage: ~1 MM Miles Discoveries Wahoo – Pre-Salt

BM-C-32 33% WI Itaipu – Pre-Salt

COALHO Espírito ITAIPU Itauna – Post-Salt Discovery Santo Basin Discovery Coalho – Post-Salt

BM-C-30 30% WI 2011 Planned Activity ITAIPU WAHOO #2 Drill 3+ Appraisal Wells Jubarte Discovery

ITAUNA Discovery WAHOO Discovery ITAUNA DISCOVERY 0 5 ITAUNA Linguado Miles Discovery Tertiary Pay Campos Basin ANADARKO WI BLOCK BM-C-29 SUCCESSFUL WELL 50% WI Santos Basin 2011 PLANNED DRILLING COMPETITOR ACTIVITY 0 250 DISCOVERY Albian Miles PROSPECT Pay Salt

Pre-Salt Show 21 www.anadarko.com | NYSE: APC Gulf of Mexico Exploration Gross Acreage: ~3 Million ExplorationExploration TrackTrack Record:Record: DiscoveredDiscovered 3232 FieldsFields 10+10+ BBOEBBOE GrossGross UnriskedUnrisked ResourceResource PotentialPotential IdentifiedIdentified ~130~130 ProspectsProspects andand LeadsLeads TargetingTargeting 100+100+ MMBOEMMBOE GrossGross ResourcesResources

REFUGIOREFUGIO RAPTORRAPTOR

VITO

HALEAKALAHALEAKALA BLACKTAILBLACKTAIL FLINTFLINT CREEKCREEK

SILVERTON KAKUNAKAKUNA SILVERTON MAUNA KEA TORREYSTORREYS MAUNA KEA DEEP NANSEN DEEP NANSEN ARCADIUSARCADIUS SAMURAI

SHENANDOAH HEIDELBERG CORONADO CORONADO RECENT DISCOVERY YUCATANYUCATAN SPARTACUSSPARTACUS MIOCENE/PLIOCENE PROSPECT LUCIUS LOWER TERTIARY PROSPECT PHOBOSPHOBOS APC ACREAGE

22 www.anadarko.com | NYSE: APC Positioned for the Future Accelerating Value from Capital-Efficient Base Realizing Tremendous Growth from Shale Plays Developing Sanctioned Mega Projects Advancing Next-Generation Mega Projects Continuing World-Class Exploration Program

PRODUCTIONPRODUCTION EXPLORATIONEXPLORATION

23