EvolutionEvolution ofof OilOil ProductionProduction inin thethe BakkenBakken FormationFormation

JulieJulie A.A. LeFeverLeFever NorthNorth DakotaDakota GeologicalGeological SurveySurvey PlaysPlays ofof thethe BakkenBakken FormationFormation ¾¾ ConventionalConventional BakkenBakken (pre(pre--1987)1987) ¾¾ CycleCycle 11 –– AntelopeAntelope StructureStructure (1950s(1950s –– 60s)60s) ¾¾ CycleCycle 22 –– DepositionalDepositional EdgeEdge (1970s(1970s –– 80s)80s) ¾¾ HorizontalHorizontal DrillingDrilling ofof thethe BakkenBakken ShaleShale (post(post--1987)1987) ¾¾ HorizontalHorizontal DrillingDrilling ofof thethe BakkenBakken MiddleMiddle MemberMember (2001(2001 toto present)present) ConventionalConventional BakkenBakken CycleCycle 11 –– AntelopeAntelope FieldField ¾¾DiscoveryDiscovery WellWell ¾¾ StanolindStanolind -- #1#1 WoodrowWoodrow StarrStarr ¾¾ InitialInitial PotentialPotential (536(536 BO;BO; 0.10.1 BW)BW) ¾¾ AntelopeAntelope FieldField ¾¾ 5252 wells;wells; 12.512.5 millionmillion BO;BO; 1010 BCFBCF GasGas ¾¾ ““SanishSanish SandSand”” ¾¾ CompletionCompletion MethodMethod Conventional Bakken Exploration between Cycles

¾¾ElkhornElkhorn RanchRanch ¾¾ ShellShell OilOil Co.Co. -- #41X#41X--55--11 GovernmentGovernment ¾¾NessonNesson AnticlineAnticline ¾¾ #1#1 B.E.B.E. HoveHove ¾¾ IPIP -- 756756 BOPD,BOPD, 33 BWPDBWPD ¾¾ CompletionCompletion MethodMethod ConventionalConventional BakkenBakken CycleCycle 22 –– DepositionalDepositional LimitLimit

¾¾StratigraphyStratigraphy && StructureStructure ¾¾ ThinThin BakkenBakken ¾¾ MultipleMultiple PaysPays ¾¾ Folds,Folds, FaultsFaults oror BothBoth ¾¾ CompletionCompletion MethodsMethods HorizontalHorizontal DrillingDrilling ofof thethe UpperUpper BakkenBakken ShaleShale

¾¾MeridianMeridian -- #33#33--1111 MOIMOI ¾¾DrilledDrilled verticalvertical ¾¾Cored,Cored, Logged,Logged, DrillDrill StemStem TestedTested ¾¾DrilledDrilled HorizontallyHorizontally -- 26032603 ftft ¾¾88 ftft -- upperupper BakkenBakken ShaleShale ¾¾IP:IP: 258258 BOPDBOPD && 299299 MCFMCF gasgas ¾¾Cost:Cost: $2$2 millionmillion LearningLearning CurveCurve z MeridianMeridian --#33#33--1111 MOIMOI ƒ 5757 daysdays toto drilldrill ƒ 27 days to drill vertical borehole ƒ 12 days to drill horizontal section ƒ $2$2 millionmillion z 33 setset ofof 1010 wellswells ƒ 3535 daysdays toto drilldrill atat aa costcost $1.08$1.08 millionmillion z EndEnd ofof PlayPlay ƒƒ $900,000$900,000 (same(same asas aa verticalvertical well)well) HorizontalHorizontal DrillingDrilling ofof thethe UpperUpper BakkenBakken ShaleShale

¾¾ DrillingDrilling MethodsMethods ¾¾ GeneralGeneral ProblemsProblems ¾¾SuccessfulSuccessful wellwell == highhigh volumesvolumes ofof oiloil HorizontalHorizontal DrillingDrilling ofof thethe BakkenBakken MiddleMiddle MemberMember

zz RichlandRichland County,County, MontanaMontana zz NorthNorth DakotaDakota WillistonWilliston BasinBasin

AB SK MB MT

ND SD

R ic h h McK WY la McK n d d e C n o zi .. e C o . MT ND StudyStudy AreaArea RichlandRichland County,County, MTMT StratigraphyStratigraphy SouthSouth NorthNorth MississippianMississippian LodgepoleLodgepole FormationFormation

n Upper Shale Member n

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k ThreeThree ForksForks k

k

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k Transitional Facies - L1 M

Ba Lower Shale Member Ba BalcronBalcron OilOil -- #44#44--2424 VairaVaira SESESESE Sec.Sec. 24,24, T.24N.,T.24N., R.54E.R.54E.

GR Density Porosity Lodgepole Fm.

0

0

upper 0

1 0 Fm. Fm.

middle Bakken Bakken

Three Forks Fm. Neutron Porosity 10604.5 ft. SESWSESW Sec.Sec. 13,13, T.23N.,R.56E.T.23N.,R.56E. AHELAHEL #1#1 H8H8 NevinsNevins RichlandRichland County,County, MTMT

BakkenBakken/Three/Three ForksForks ContactContact SESWSESW Sec.Sec. 13,13, T.23N.,R.56E.T.23N.,R.56E. AHELAHEL #1#1 H8H8 NevinsNevins RichlandRichland County,County, MTMT

MiddleMiddle MemberMember LithofaciesLithofacies 22 SESWSESW Sec.Sec. 13,13, T.23N.,R.56E.T.23N.,R.56E. AHELAHEL #1#1 H8H8 NevinsNevins RichlandRichland County,County, MTMT

MiddleMiddle MemberMember LithofaciesLithofacies 22 (producing(producing faciesfacies)) 10582 ft SESWSESW Sec.Sec. 13,13, T.23N.,R.56E.T.23N.,R.56E. AHELAHEL #1#1 H8H8 NevinsNevins RichlandRichland County,County, MTMT

UpperUpper Shale/MiddleShale/Middle MbrMbr ContactContact BLCSBLCS StructureStructure MapMap

-5700 ft -5800 -5900 -6000

-6100 l

l -6200

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t -6400

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C -6800 -6900 -7000 -7100 -7200 -7300 -7400 -7500 Montana North Dakota FormationFormation LimitsLimits

Bakken Formation

Upper

Middle

Lower

Prairie Salt Edge

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Montana North Dakota IsopachIsopach ofof thethe BakkenBakken FormationFormation

140ft 130

120 l

l 110

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80

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o C C 50 40 30 20 10 0 Montana North Dakota IsopachIsopach ofof thethe UpperUpper MemberMember BakkenBakken FormationFormation

32

28 ft

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0 Montana North Dakota IsopachIsopach ofof thethe MiddleMiddle MemberMember BakkenBakken FormationFormation 70 65 60 55 50 45 40 ft 35

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20

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o C C 10 5 0 Montana North Dakota MiddleMiddle MemberMember PorosityPorosity ZoneZone

12 %

l 10

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0 Contour Interval: 2 ft. BakkenBakken MiddleMiddle MemberMember PrairiePrairie SaltSalt 70 65 60 55 Prairie Salt Edge50 45 40 ft 35

30

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o C C 10 5 0 Montana North Dakota BakkenBakken MiddleMiddle MemberMember PrairiePrairie SaltSalt 70 65 60 Prairie Salt 55 50 45 40 35 ft

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o C C 10 5 0 Montana North Dakota RichlandRichland CountyCounty

8080 ProducingProducing FieldsFields 1.1. RedRed RiverRiver FmFm 2.2. MadisonMadison FmFm 3.3. BakkenBakken FmFm 4.4. DuperowDuperow FmFm 5.5. InterlakeInterlake FmFm 2020 FieldsFields produce(d)produce(d) fromfrom thethe BakkenBakken FormationFormation

08/2004 BakkenBakken FormationFormation RichlandRichland County,County, MTMT

¾ HistoricallyHistorically –– ¾ 4242 BakkenBakken wellswells ++ 88 commingledcommingled wellswells ¾ CurrentlyCurrently –– ¾ 127127 BakkenBakken ProducersProducers ¾ Horizontals – 92 producers, 1 PNA, 1 Dry ¾ TotalTotal productionproduction ¾ 2000 – 2,618,982 BO ¾ 2003 – 5,284,378 BO ¾ 2004 – 3,275,061 BO (thru August, 2004) ¾ 8686 ProducingProducing Fields,Fields, 2323 -- BakkenBakken ProductionProduction 08/2004 DrillingDrilling && CompletionCompletion BakkenBakken HorizontalsHorizontals

¾¾ TwoTwo lateralslaterals toto aa 12801280 spacingspacing unitunit ¾¾ WellWell isis stimulatedstimulated withwith largelarge fracturefracture treatmenttreatment (~920,000#,(~920,000#, gelledgelled water/sandwater/sand fracfrac)) ¾¾ CostCost $2.2$2.2 millionmillion ¾¾500500--700700 BOPDBOPD initiallyinitially ¾¾VirtuallyVirtually nono waterwater HorizontalHorizontal DrillingDrilling ofof thethe BakkenBakken MiddleMiddle MemberMember

zz RichlandRichland County,County, MontanaMontana zz NorthNorth DakotaDakota LithofaciesLithofacies ofof thethe MiddleMiddle MemberMember

Upper Shale Lithofacies 5 - Siltstone

Lithofacies 4 – Interbedded Dark Grey Shale and Buff Silty Sandstone

Lithofacies 3 - Sandstone Productive Lithofacies 2 – Interbedded Dark Grey Shale and Buff Silty Sandstone Productive in MT

Lithofacies 1 - Siltstone

Lower Shale (From LeFever and others, 1991) LithofaciesLithofacies 33 SENWSENW Sec.Sec. 11,11, T160N,T160N, R95WR95W ConocoConoco,, Inc.Inc. -- #17#17 WatterudWatterud ““AA””

GR Res

Producing Zone

Upper L2 Facies JoiletteJoilette OilOil (USA),(USA), LLC.LLC. #1#1--17R17R RobertRobert HeuerHeuer

¾¾ SadlerSadler FieldField ¾¾ ReRe--entryentry ofof aa MadisonMadison TestTest (02/13/1981) ¾¾ BakkenBakken CompletionCompletion ¾¾03/05/200403/05/2004 ¾¾IPIP –– 8787 BOPD,BOPD, 150150 MCF,MCF, 142142 BWPDBWPD ¾¾FractureFracture StimulatedStimulated ¾¾ ProducingProducing ZoneZone –– LithofaciesLithofacies 33 WhatWhat DoDo WeWe Know?Know?

¾¾ RocksRocks TypesTypes (Montana=North(Montana=North Dakota)Dakota) ¾¾AdditionalAdditional ProductiveProductive SectionSection ¾Lithofacies 3, “Sanish”, lower Lodgepole Limestone ¾¾ SaltSalt CollapseCollapse ¾¾ CompletionCompletion MethodsMethods ¾¾ HighHigh ProductionProduction RatesRates ConclusionsConclusions

¾¾ HorizontalHorizontal DrillingDrilling MiddleMiddle MemberMember == SuccessSuccess