Evolution of Oil ProductionEvolution of Oil Production in the Bakken Formationin the Bakken Formation

Julie A. LeFeverJulie A. LeFeverNorth Dakota Geological SurveyNorth Dakota Geological Survey

Conventional Bakken (pre-1987)Conventional Bakken (pre-1987) Cycle 1 – Antelope Structure (1950s – 60s)Cycle 1 – Antelope Structure (1950s – 60s) Cycle 2 – Depositional Edge (1970s – 80s)Cycle 2 – Depositional Edge (1970s – 80s)

Horizontal Drilling of the Bakken Shale (post-1987)Horizontal Drilling of the Bakken Shale (post-1987) Horizontal Drilling of the Bakken Middle Member Horizontal Drilling of the Bakken Middle Member (2001 to present)(2001 to present)

Plays of thePlays of theBakken FormationBakken Formation

Conventional Bakken Conventional Bakken Cycle 1 – Antelope FieldCycle 1 – Antelope Field

Discovery Well Discovery Well Stanolind - #1 Woodrow StarrStanolind - #1 Woodrow Starr

Initial Potential (536 BO; 0.1 BW)Initial Potential (536 BO; 0.1 BW)

Antelope FieldAntelope Field 52 wells; 12.5 million BO; 10 BCF Gas52 wells; 12.5 million BO; 10 BCF Gas “ “Sanish Sand”Sanish Sand” Completion MethodCompletion Method

Conventional BakkenExploration between Cycles

Elkhorn RanchElkhorn Ranch Shell Oil Co. - #41X-5-1 GovernmentShell Oil Co. - #41X-5-1 Government

Nesson Anticline Nesson Anticline #1 B.E. Hove#1 B.E. Hove

IP - 756 BOPD, 3 BWPDIP - 756 BOPD, 3 BWPD Completion MethodCompletion Method

Conventional Bakken Conventional Bakken Cycle 2 – Depositional LimitCycle 2 – Depositional Limit

Stratigraphy & StructureStratigraphy & Structure Thin BakkenThin Bakken Multiple PaysMultiple Pays Folds, Faults or BothFolds, Faults or Both Completion MethodsCompletion Methods

Horizontal Drilling of the Horizontal Drilling of the Upper Bakken ShaleUpper Bakken Shale

Meridian - #33-11 MOIMeridian - #33-11 MOI Drilled verticalDrilled vertical

Cored, Logged, Drill Stem TestedCored, Logged, Drill Stem Tested

Drilled Horizontally - 2603 ftDrilled Horizontally - 2603 ft 8 ft - upper Bakken Shale 8 ft - upper Bakken Shale

IP: 258 BOPD & 299 MCF gasIP: 258 BOPD & 299 MCF gasCost: $2 millionCost: $2 million

Learning CurveLearning Curve

Meridian -#33-11 MOIMeridian -#33-11 MOI 57 days to drill57 days to drill

27 days to drill vertical borehole27 days to drill vertical borehole 12 days to drill horizontal section12 days to drill horizontal section

$2 million$2 million

3 set of 10 wells 3 set of 10 wells 35 days to drill at a cost $1.08 million35 days to drill at a cost $1.08 million

End of Play End of Play $900,000 (same as a vertical well)$900,000 (same as a vertical well)

Horizontal Drilling of the Horizontal Drilling of the Upper Bakken ShaleUpper Bakken Shale

Drilling Methods Drilling Methods General ProblemsGeneral Problems

Successful well = high volumes of oilSuccessful well = high volumes of oil

Horizontal Drilling of the Horizontal Drilling of the Bakken Middle MemberBakken Middle Member

Richland County, MontanaRichland County, MontanaNorth DakotaNorth Dakota

MTMT

WYWY

SDSD

NDND

MBMBSKSKABAB

Richland

Richland Co. Co.

McKenzie Co.

McKenzie Co.

MTMT NDND Study AreaStudy Area

Williston BasinWilliston Basin

Richland County, MTRichland County, MTStratigraphyStratigraphy

NorthNorthSouthSouth

DevonianDevonianThree ForksThree Forks

Mississippian Lodgepole FormationMississippian Lodgepole Formation

Mis

siss

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Lower Shale MemberLower Shale Member

Transitional Facies – L7Transitional Facies – L7

Transitional Facies - L1Transitional Facies - L1

Lithofacies 2

Lithofacies 2

Upper (Productive)Upper (Productive)

LowerLower

Balcron Oil - #44-24 VairaBalcron Oil - #44-24 VairaSESE Sec. 24, T.24N., R.54E.SESE Sec. 24, T.24N., R.54E.

Neutron PorosityNeutron Porosity

DensityDensity PorosityPorosity

GRGR

Lodgepole Fm.Lodgepole Fm.

Three Forks Fm.Three Forks Fm.

Bakken

Fm

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akken

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middle

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10604.5 ft.10604.5 ft.

Bakken/Three ForksBakken/Three ForksContactContact

SESW Sec. 13, T.23N.,R.56E.SESW Sec. 13, T.23N.,R.56E.AHEL #1 H8 NevinsAHEL #1 H8 NevinsRichland County, MTRichland County, MT

Middle MemberMiddle MemberLithofacies 2Lithofacies 2

SESW Sec. 13, T.23N.,R.56E.SESW Sec. 13, T.23N.,R.56E.

AHEL #1 H8 NevinsAHEL #1 H8 Nevins

Richland County, MTRichland County, MT

Middle MemberMiddle MemberLithofacies 2Lithofacies 2

(producing facies)(producing facies)

SESW Sec. 13, T.23N.,R.56E.SESW Sec. 13, T.23N.,R.56E.

AHEL #1 H8 NevinsAHEL #1 H8 Nevins

Richland County, MTRichland County, MT

SESW Sec. 13, T.23N.,R.56E.SESW Sec. 13, T.23N.,R.56E.

AHEL #1 H8 NevinsAHEL #1 H8 Nevins

Richland County, MTRichland County, MT

Upper Shale/Middle MbrUpper Shale/Middle MbrContactContact

10582 ft10582 ft

- 7500- 7400- 7300- 7200- 7100- 7000- 6900- 6800- 6700- 6600- 6500- 6400- 6300- 6200- 6100- 6000- 5900- 5800- 5700

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MontanaMontana North DakotaNorth Dakota

BLCS Structure MapBLCS Structure Map

Formation LimitsFormation Limits

?

MontanaMontana North DakotaNorth Dakota

Bakken FormationBakken Formation

UpperUpper

MiddleMiddle

LowerLower

Prairie Salt EdgePrairie Salt Edge

ft

0102030405060708090100110120130140

Isopach of the Bakken FormationIsopach of the Bakken Formation

MontanMontanaa

North DakotaNorth Dakota

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Isopach of the Upper MemberIsopach of the Upper MemberBakken FormationBakken Formation

MontanaMontana North DakotaNorth Dakota

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North DakotaNorth DakotaMontanaMontana

Isopach of the Middle MemberIsopach of the Middle MemberBakken FormationBakken Formation

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McKenzie Co.

McKenzie Co.

Richland Co.

Richland Co.

Middle MemberMiddle MemberPorosity ZonePorosity Zone

Contour Interval: 2 ft.Contour Interval: 2 ft.

0

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Bakken Middle MemberBakken Middle MemberPrairie SaltPrairie Salt

MontanaMontana North DakotaNorth Dakota

Prairie Salt Prairie Salt EdgeEdge

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Prairie Salt Prairie Salt

Bakken Middle MemberBakken Middle MemberPrairie SaltPrairie Salt

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MontanaMontana NorthNorth DakotaDakota

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80 Producing Fields80 Producing Fields1. Red River Fm1. Red River Fm2. Madison Fm 2. Madison Fm 3. Bakken Fm3. Bakken Fm4. Duperow Fm4. Duperow Fm5. Interlake Fm5. Interlake Fm

20 Fields produce(d) from the 20 Fields produce(d) from the Bakken FormationBakken Formation

Richland CountyRichland County

08/2004

Bakken FormationBakken FormationRichland County, MTRichland County, MT

Historically –Historically – 42 Bakken wells + 8 commingled wells42 Bakken wells + 8 commingled wells

Currently –Currently – 127 Bakken Producers127 Bakken Producers

Horizontals – 92 producers, 1 PNA, 1 DryHorizontals – 92 producers, 1 PNA, 1 Dry

Total production Total production 2000 – 2,618,982 BO2000 – 2,618,982 BO 2003 – 5,284,378 BO2003 – 5,284,378 BO 2004 – 3,275,061 BO (thru August, 2004)2004 – 3,275,061 BO (thru August, 2004)

86 Producing Fields, 23 - Bakken Production86 Producing Fields, 23 - Bakken Production

08/2004

Drilling & CompletionDrilling & CompletionBakken HorizontalsBakken Horizontals

Two laterals to a 1280 spacing unit Two laterals to a 1280 spacing unit Well is stimulated with large fracture Well is stimulated with large fracture

treatment treatment (~920,000#, gelled water/sand frac)(~920,000#, gelled water/sand frac)

Cost $2.2 millionCost $2.2 million 500-700 BOPD initially500-700 BOPD initiallyVirtually no waterVirtually no water

Horizontal Drilling of the Horizontal Drilling of the Bakken Middle MemberBakken Middle Member

Richland County, MontanaRichland County, MontanaNorth DakotaNorth Dakota

Lithofacies 5 - SiltstoneLithofacies 5 - Siltstone

Lithofacies 4 – Interbedded Dark Grey ShaleLithofacies 4 – Interbedded Dark Grey Shale and Buff Silty Sandstone and Buff Silty Sandstone

Lithofacies 3 - SandstoneLithofacies 3 - Sandstone

Lithofacies 2 – Interbedded Dark Grey ShaleLithofacies 2 – Interbedded Dark Grey Shale and Buff Silty Sandstoneand Buff Silty Sandstone

Lithofacies 1 - SiltstoneLithofacies 1 - Siltstone

(From LeFever and others, 1991)Lower Shale

Upper Shale

Lithofacies of the Middle MemberLithofacies of the Middle Member

Productive in MTProductive in MT

ProductiveProductive

Lithofacies 3Lithofacies 3

Producing ZoneProducing Zone

SENW Sec. 11, T160N, R95W SENW Sec. 11, T160N, R95W Conoco, Inc. - #17 Watterud “A”Conoco, Inc. - #17 Watterud “A”

Upper L2 FaciesUpper L2 Facies

GRGR ResRes

Joilette Oil (USA), LLC.Joilette Oil (USA), LLC.#1-17R Robert Heuer#1-17R Robert Heuer

Sadler FieldSadler Field Re-entry of a Madison Test Re-entry of a Madison Test (02/13/1981)(02/13/1981)

Bakken Completion Bakken Completion 03/05/200403/05/2004 IP – 87 BOPD, 150 MCF, 142 BWPDIP – 87 BOPD, 150 MCF, 142 BWPDFracture StimulatedFracture Stimulated

Producing Zone – Lithofacies 3Producing Zone – Lithofacies 3

What Do We Know?What Do We Know?

Rocks Types (Montana=North Dakota)Rocks Types (Montana=North Dakota)Additional Productive SectionAdditional Productive Section

Lithofacies 3, “Sanish”, lower Lodgepole LimestoneLithofacies 3, “Sanish”, lower Lodgepole Limestone

Salt CollapseSalt Collapse Completion MethodsCompletion Methods High Production RatesHigh Production Rates

ConclusionsConclusions

Horizontal Drilling Horizontal Drilling

Middle Member = SuccessMiddle Member = Success