1. All rights reserved. Enterprise Products Partners L.P.1 Why Natural Gas Liquids are Important to the Wyoming Natural Gas Industry or Support Your Local Cryogenic Processing Plant Presented to Wyoming Pipeline Authority August 24, 2004

2. All rights reserved. Enterprise Products Partners L.P.2 Why Natural Gas Liquids are Important to the Wyoming Natural Gas Industry Presentation OverviewPresentation Overview Brief introduction to Enterprise and Mid-America Pipeline (MAPL)Brief introduction to Enterprise and Mid-America Pipeline (MAPL) MAPL’s relationship to Wyoming and the natural gas pipeline industryMAPL’s relationship to Wyoming and the natural gas pipeline industry Comparison of MAPL to natural gas pipelinesComparison of MAPL to natural gas pipelines What MAPL gives WyomingWhat MAPL gives Wyoming What Wyoming gives MAPLWhat Wyoming gives MAPL System operation and expansion opportunitiesSystem operation and expansion opportunities Future of natural gas liquids in the Rockies (Wyoming)Future of natural gas liquids in the Rockies (Wyoming)

3. All rights reserved. Enterprise Products Partners L.P.3 Overview of Enterprise (EPD) 2 nd largest publicly traded energy partnership serving producers and consumers of natural gas and natural gas liquids (NGLs)  IPO in July 1998  Currently ranked 336 th on Fortune 500 and 7 th on Forbes list of America’s 25 Fastest-Growing Big Companies Large platform of assets across the midstream energy value chain  Only integrated natural gas and NGL transportation, fractionation, processing, storage and import/export network in North America  Pending merger with GulfTerra Energy Partners (GTM) adds complementary scale, scope and diversity to existing operations

4. All rights reserved. Enterprise Products Partners L.P.4 SYSTEM MAP OF COMBINED ENTERPRISE (“EPD”) AND GULFTERRA (“GTM”) Combined System Map ROCK SPRINGS ST. PAUL AUX SABLE HOBBS CONWAY MT. BELVIEU HOUSTON SYSTEM MAP OF ENTERPRISE (“EPD”) w/ South Texas Midstream Assets

5. All rights reserved. Enterprise Products Partners L.P.5 Relative Position Across the Value Chain (By Capacity) Leading Business Positions Across Value Chain Gas Gathering Gas Processing Raw Mix Pipeline Fractionation Salt Dome Storage Import Terminal Export Terminal Distribution

6. All rights reserved. Enterprise Products Partners L.P.6 Introduction to Mid-America Pipeline (MAPL) Approximately 7,500 miles of pipelineApproximately 7,500 miles of pipeline Transports approximately 700,000 barrels per dayTransports approximately 700,000 barrels per day Operates in 14 statesOperates in 14 states FERC regulatedFERC regulated

7. All rights reserved. Enterprise Products Partners L.P.7 Mid-America Pipeline Company Wyoming History and Relationship

8. All rights reserved. Enterprise Products Partners L.P.8 Pipeline constructed in 1982Pipeline constructed in 1982 Expanded in 1999Expanded in 1999 Expanded in 2006?Expanded in 2006? Largest of two natural gas liquids pipelines leaving WyomingLargest of two natural gas liquids pipelines leaving Wyoming Transported average 106,000 bpd in 2002Transported average 106,000 bpd in 2002 (4.4 million gallons per day)(4.4 million gallons per day) Connected to 15 gas processing plantsConnected to 15 gas processing plants Served 2.2 BCFD of gas processing in 2003 (46% of total)Served 2.2 BCFD of gas processing in 2003 (46% of total) Transports liquids 1,500 miles to market (Gulf Coast)Transports liquids 1,500 miles to market (Gulf Coast) 1,250 miles as the crow flies1,250 miles as the crow flies Mid-America Pipeline Company Wyoming History and Relationship

9. All rights reserved. Enterprise Products Partners L.P.9 Mid-America Pipeline Company Where Does 1,250 Miles Get You?

10. All rights reserved. Enterprise Products Partners L.P.10 Comparison of MAPL to Natural Gas Pipelines

11. All rights reserved. Enterprise Products Partners L.P.11 Comparison of MAPL to Natural Gas Pipelines Who are the largest natural gas transporters out of Wyoming?Who are the largest natural gas transporters out of Wyoming? 2002 Volumes MMBTU / Day 774,4891,166,000755,477509,180408,298311,520194,226164,357119,946 Kern River Wyoming Interstate TrailblazerNorthwestCIG Kinder Morgan Questar Southern Star Central Williston Basin

12. All rights reserved. Enterprise Products Partners L.P.12 2002 Volumes MMBTU / Day 774,4891,166,000755,477509,180408,298353,290311,520194,226164,357119,946 Kern River Wyoming Interstate TrailblazerNorthwestCIG Mid-America Pipeline Kinder Morgan Questar Southern Star Central Williston Basin Comparison of MAPL to Natural Gas Pipelines Who are the largest natural gas transporters out of Wyoming?Who are the largest natural gas transporters out of Wyoming?

13. All rights reserved. Enterprise Products Partners L.P.13 2002 Volumes MMBTU / Day 774,4891,166,000755,477509,180353,290408,298311,520194,226164,357119,946 Kern River Wyoming Interstate TrailblazerNorthwest Mid-America Pipeline CIG Kinder Morgan Questar Southern Star Central Williston Basin 2002 Volumes Sales Value / Day $ 4.9 MM $ 7.3 MM $ 4.8 MM $ 3.2 MM $ 2.8 MM $ 2.6 MM $ 2.0 MM $ 1.2 MM $ 1.0 MM $ 0.8 MM Who are the largest natural gas transporters out of Wyoming?Who are the largest natural gas transporters out of Wyoming? Comparison of MAPL to Natural Gas Pipelines

14. All rights reserved. Enterprise Products Partners L.P.14 What MAPL gives Wyoming Processing Economics (Ethane Recovery) Ethane57% $ 0.569 $ 0.024 $ 0.072 $ 0.473 66,369 $ 7.13 $ 5.02 Propane25% $ 0.885 $ 0.024 $ 0.072 $ 0.789 91,599 $ 8.61 $ 5.02 Isobutane5% $ 0.950 $ 0.024 $ 0.072 $ 0.854 99,652 $ 8.57 $ 5.02 Normal Butane 7% $ 0.968 $ 0.024 $ 0.072 $ 0.872 103,724 $ 8.40 $ 5.02 Gasoline6% $ 1.081 $ 0.024 $ 0.072 $ 0.985 110,000 $ 8.96 $ 5.02 Weighted Average $ 0.726 $ 0.024 $ 0.072 $ 0.63 79,606 $ 7.91 $ 5.02 8/16/04 Mont Belvieu Liquid Price $ / gallon Fractionation Cost @ $ 5.94 gas (Houston Ship Channel) Pipeline Transportation Wyoming Liquid Value BTU / gallon Liquid Value $ / MMBTU Kern River Index (8/16/04)

15. All rights reserved. Enterprise Products Partners L.P.15 What MAPL gives Wyoming Processing Economics (Ethane Recovery) By having access to the NGL pipeline (8/16/2004 example):By having access to the NGL pipeline (8/16/2004 example): 353,290 MMBTU is “sold” at $ 7.91 / MMBTU353,290 MMBTU is “sold” at $ 7.91 / MMBTU 2,310,000 MMBTU is “sold” at $ 5.02 / MMBTU2,310,000 MMBTU is “sold” at $ 5.02 / MMBTU 2,663,290 MMBTU is “sold” at $ 5.40 / MMBTU2,663,290 MMBTU is “sold” at $ 5.40 / MMBTU The NGL outlet provided a $ 0.38 / MMBTU upgrade to the gas priceThe NGL outlet provided a $ 0.38 / MMBTU upgrade to the gas price The NGL outlet provides over $ 1 Million / day upgrade to gas ownersThe NGL outlet provides over $ 1 Million / day upgrade to gas owners Approximately $ 370 Million annualizedApproximately $ 370 Million annualized The NGL outlet proves approximately 20% of the value to gas ownersThe NGL outlet proves approximately 20% of the value to gas owners Approximately 70% of this value comes from ethane and propaneApproximately 70% of this value comes from ethane and propane

16. All rights reserved. Enterprise Products Partners L.P.16 What MAPL gives Wyoming Processing Economics (Ethane Rejection) Ethane40% $ 0.392 $ 0.021 $ 0.072 $ 0.299 66,369 $ 4.51 $ 5.02 Propane32% $ 0.598 $ 0.021 $ 0.072 $ 0.505 91,599 $ 5.51 $ 5.02 Isobutane9% $ 0.660 $ 0.021 $ 0.072 $ 0.567 99,652 $ 5.69 $ 5.02 Normal Butane 10% $ 0.674 $ 0.021 $ 0.072 $ 0.581 103,724 $ 5.60 $ 5.02 Gasoline9% $ 0.798 $ 0.021 $ 0.072 $ 0.705 110,000 $ 6.41 $ 5.02 Weighted Average $ 0.547 $ 0.021 $ 0.072 $ 0.454 85,100 $ 5.33 $ 5.02 2/6/04 Mont Belvieu Liquid Price $ / gallon Fractionation Cost @ $ 5.27 gas (Houston Ship Channel) Pipeline Transportation Wyoming Liquid Value BTU / gallon Liquid Value $ / MMBTU Kern River Index (2/6/04)

17. All rights reserved. Enterprise Products Partners L.P.17 What MAPL gives Wyoming Processing Economics (Ethane Rejection) By having access to the NGL pipeline (8/16/2004 example):By having access to the NGL pipeline (8/16/2004 example): 214,453 MMBTU is “sold” at $ 5.33 / MMBTU214,453 MMBTU is “sold” at $ 5.33 / MMBTU 2,448,837 MMBTU is “sold” at $ 5.02 / MMBTU2,448,837 MMBTU is “sold” at $ 5.02 / MMBTU 2,663,290 MMBTU is “sold” at $ 5.04 / MMBTU2,663,290 MMBTU is “sold” at $ 5.04 / MMBTU The NGL outlet provided a $ 0.02 / MMBTU upgrade to the gas priceThe NGL outlet provided a $ 0.02 / MMBTU upgrade to the gas price The NGL outlet provides over $ 50,000 upgrade to gas ownersThe NGL outlet provides over $ 50,000 upgrade to gas owners Approximately $ 18.5 Million annualizedApproximately $ 18.5 Million annualized The NGL outlet proves approximately 9 % of the value to gas ownersThe NGL outlet proves approximately 9 % of the value to gas owners

18. All rights reserved. Enterprise Products Partners L.P.18 What MAPL gives Wyoming Over the past 5 1/2 years:Over the past 5 1/2 years: NGL pipeline has provided an aggregate $ 725 Million premium to Wyoming gas ownersNGL pipeline has provided an aggregate $ 725 Million premium to Wyoming gas owners NGL pipeline has averaged an $ 130 Million annual premium to Wyoming gas ownersNGL pipeline has averaged an $ 130 Million annual premium to Wyoming gas owners

19. All rights reserved. Enterprise Products Partners L.P.19 What Wyoming Gives MAPL Published tariff (Incentive) from Wyoming to Gulf Coast: $ 0.072 / gallonPublished tariff (Incentive) from Wyoming to Gulf Coast: $ 0.072 / gallon Annual volume moved during 2002: 1,619,875,110 gallonsAnnual volume moved during 2002: 1,619,875,110 gallons Revenue received during 2002: $ 116,631,008Revenue received during 2002: $ 116,631,008 Total MAPL revenue during 2002: $ 269,367,769Total MAPL revenue during 2002: $ 269,367,769 Percentage of MAPL revenue earned from Wyoming43 %Percentage of MAPL revenue earned from Wyoming43 %

20. All rights reserved. Enterprise Products Partners L.P.20 System Operations Wyoming South: Capacity of 125,000 bpdWyoming South: Capacity of 125,000 bpd Transports: 100,000 bpdTransports: 100,000 bpd Grand Junction South: Capacity of 200,000 bpdGrand Junction South: Capacity of 200,000 bpd Transports: 125,000 bpdTransports: 125,000 bpd San Juan Basin South: Capacity of 215,000 bpdSan Juan Basin South: Capacity of 215,000 bpd Transports: 200,000 bpdTransports: 200,000 bpd

21. All rights reserved. Enterprise Products Partners L.P.21 System Operations Rocky Mountain Pipeline System Utilization

22. All rights reserved. Enterprise Products Partners L.P.22 System Operations Key Observations Since Opal expansion in 2000, MAPL has been operationally full, or declines have matched growth almost exactlySince Opal expansion in 2000, MAPL has been operationally full, or declines have matched growth almost exactly Ethane margins can cut MAPL volumes by 25 %Ethane margins can cut MAPL volumes by 25 % Corresponding gas pipeline increase approximately 6%Corresponding gas pipeline increase approximately 6% Next round of plant expansions will over fill pipeline, and force plants into ethane / propane rejectionNext round of plant expansions will over fill pipeline, and force plants into ethane / propane rejection Without MAPL expansion NGL value enhancement opportunities will shrink or go awayWithout MAPL expansion NGL value enhancement opportunities will shrink or go away

23. All rights reserved. Enterprise Products Partners L.P.23 System Operations Expansion Opportunity MAPL is spending $ 20 Million to permit a 50,000 bpd expansion out of WyomingMAPL is spending $ 20 Million to permit a 50,000 bpd expansion out of Wyoming Permit should be obtained in 4Q 2005Permit should be obtained in 4Q 2005 Pipeline could be in service 3Q 2006Pipeline could be in service 3Q 2006 Completed expansion would cost $ 150 - 170 MillionCompleted expansion would cost $ 150 - 170 Million 200 miles of pipe200 miles of pipe 23 pump stations modified and expanded23 pump stations modified and expanded Further information can be found atFurther information can be found athttp://www.epplp.com/mapl/EPPindex3.htm Unique challenge: Expansion must be full to provide adequate returnUnique challenge: Expansion must be full to provide adequate return

24. All rights reserved. Enterprise Products Partners L.P.24 Future of NGLs in Wyoming Summary and Dilemma San Juan basin has remained flat to slight increases in NGL productionSan Juan basin has remained flat to slight increases in NGL production Piceance / Uintah basin experiencing growthPiceance / Uintah basin experiencing growth Southwest Wyoming experiencing growthSouthwest Wyoming experiencing growth Under current philosophy, MAPL must build expansion on speculative basis, no “Open Season”Under current philosophy, MAPL must build expansion on speculative basis, no “Open Season” As regulated pipeline, difference between cost of capital and maximum allowable return less than 10%As regulated pipeline, difference between cost of capital and maximum allowable return less than 10% Decision to expand is based more on the relative value of NGLs to natural gas, rather than simply natural gas production growth or Wyoming gas pricesDecision to expand is based more on the relative value of NGLs to natural gas, rather than simply natural gas production growth or Wyoming gas prices Without pipeline expansion, value opportunities diminish or disappear as dewpoint control volumes replace discretionary volumesWithout pipeline expansion, value opportunities diminish or disappear as dewpoint control volumes replace discretionary volumes

25. All rights reserved. Enterprise Products Partners L.P.25 Future of NGLs in Wyoming Summary and Dilemma Decision to expand is made based on ratio of NGL prices to Wyoming gas priceDecision to expand is made based on ratio of NGL prices to Wyoming gas price Expansion decision will be made based on ethane and propane marginsExpansion decision will be made based on ethane and propane margins With little or no ethane and propane extraction, expansion is not necessary, or can be delayedWith little or no ethane and propane extraction, expansion is not necessary, or can be delayed All things being equal……Best case scenario….. Wyoming gas price increase NGL Extraction Value, MAPL volumes Profitability of pipeline expansion Wyoming gas price increase NGL Extraction Value, MAPL volumes Profitability of pipeline expansion

26. All rights reserved. Enterprise Products Partners L.P.26 Future of NGLs in Wyoming MAPL is financially 10 - 15% committed to pipeline expansionMAPL is financially 10 - 15% committed to pipeline expansion We are working with producers / processors to build cryogenic plants to preserve the option to extract ethane and propane to enhance valueWe are working with producers / processors to build cryogenic plants to preserve the option to extract ethane and propane to enhance value We can manage some of the ethane / propane margin risks to pipelineWe can manage some of the ethane / propane margin risks to pipeline Pipeline expansion provides growth of pipeline revenue for MAPL and value enhancement for WyomingPipeline expansion provides growth of pipeline revenue for MAPL and value enhancement for Wyoming Cryogenic plants are the key to successful MAPL expansionCryogenic plants are the key to successful MAPL expansion Cryogenic plants provide the necessary volume, and the discretionary ethane and propane to fill an expansionCryogenic plants provide the necessary volume, and the discretionary ethane and propane to fill an expansion

27. All rights reserved. Enterprise Products Partners L.P.27 Support Your Local Cryogenic Processing Plants