wattenberg field area, a near miss & lessons learned after 35

Stephen A. SonnenbergRobert J. Weimer

Stephen A. SonnenbergRobert J. Weimer

Wattenberg Field Area, A Near Miss &

Lessons Learned After 35 Years of Development History

Wattenberg Field Area, A Near Miss &

Lessons Learned After 35 Years of Development History

WYOMING

NEBRASKA

KANSAS--200

020

00--300

030

00--400

040

00

--500

050

00

-- 600

060

00

--20002000--3000

3000--40004000

--50005000-- 6000

6000

COLORADO

DENVER

Ran

geFr

ont

WATTENBERG

Wattenberg Field – DJ Basin Wattenberg Field – DJ Basin

Pay

Source Rock

Source Rock

TypicalDepth

4300’

4800’

6800’

7100’

7600’

7800’DAKOTA SAND

SKULL CREEK SHALE

J3 SAND J2 SAND

GRANEROS SHALE

GREENHORN LS

CARLILE SHALE

CODELL SANDFT HAYS LIMESTONE

NIOBRARA “C”

NIOBRARA “B”

NIOBRARA “A”

SHANNON (HYGIENE) SS

SUSSEX (TERRY) SS

PIERRE SHALE

PIERRE SHALE

PIERRE SHALE

D Sand

Sonnenberg, 2002

Diagrammatic Cross-SectionDenver Basin

Diagrammatic CrossDiagrammatic Cross--SectionSectionDenver BasinDenver Basin

WATTENBERGFIELD

Source Rock

Sussex

Shannnon

Basement

Basement

Source Rock

A A’

WestWest EastEastBasin Center Accumulation with:Six Potential ReservoirsMain Pays: J Sandstone with Codell commingleSecondary Objectives: Dakota, Niobrara, Sussex, Shannon

Niobrara

Codell

J Sandstone

Dakota

Gustason and Sonnenberg, 2003

Weimer & Ray, 1997

A Near Miss!All DSTs or cores taken in the J indicated shows of gas

Core analyses of the J compared with those of the Dakota in the SJB

Old wells in area remarkably similar

Earlier discovery at Roundup - 1967

Wattenberg discovered - 1970

History of Wattenberg Gas FieldHistory of History of Wattenberg Gas FieldWattenberg Gas Field

Matuszczak, 1973

Original Est. EUR1.3 TCF

Conventional & Unconventional Reservoirs & The Resource Triangle

Conventional & Unconventional Reservoirs & The Resource Triangle

Conventional reservoirsSmall volumes that areeasy to develop

Unconventionallarge volumes difficult to develop

Impr

oved

tech

nolo

gy

Incr

ease

d pr

icin

g

Holditch, 2005

Currently Productive Areas-GWA

Wright, 2005; Modified after Ladd, 2001

J SSDiscovery

Sussex/ShannonDiscovery

CodellDiscovery

DakotaDiscovery

Wright, 2005

Cumulative Production GWACumulative Production GWA

786

1524220

1302

180

Sussex/Shannon

Codell/Niobrara

D SS

J SS

Other

Cum: 4012 BCFe (34%)

Modified from Wright, 2005

GWA Spacing HistoryGWA Spacing History

• 1970: 320 acre units for drilling & spacing of J Sand• 1979: Additional J Sand well allowed per 320 acre unit • 1980: Section 29 tax credit; Tight gas sand designation (exp.

2002)• 1983: Codell spaced on 80 acre• 1984,85: Niobrara added to Codell spacing order• 1991: J Sand wells can be recompleted to C-N & commingling

of all downhole zones allowed• 1998: Rule 318A allows 5 wells per quarter section in GWA for

all Cretaceous age formations (81 townships)• 2005: Rule 318A modified to allow for section line & quarter

section line wells (~ 20 acre spacing 27 townships)

• 1970: 320 acre units for drilling & spacing of J Sand• 1979: Additional J Sand well allowed per 320 acre unit • 1980: Section 29 tax credit; Tight gas sand designation (exp.

2002)• 1983: Codell spaced on 80 acre• 1984,85: Niobrara added to Codell spacing order• 1991: J Sand wells can be recompleted to C-N & commingling

of all downhole zones allowed• 1998: Rule 318A allows 5 wells per quarter section in GWA for

all Cretaceous age formations (81 townships)• 2005: Rule 318A modified to allow for section line & quarter

section line wells (~ 20 acre spacing 27 townships)

Modified from Wright, 2005 & Weimer, 2005

Oil & Gas Field GrowthOil & Gas Field Growth

Produced

Reserves

Step outsInfill drilling

New horizonsImproved economics

Improved geologic modelImproved reservoir model

Improved technologiesFracture stimulationDrilling & completion

RecompletionsChanging operatorEnhanced recovery

Level oftechnology

required

Low

High

Resourcequality

Rese

rve

Gro

wth

High

Low

Sonnenberg, 04

The WattenbergGeothermal

Anomaly

Vitrinite ReflectanceValues, %Ro

The WattenbergGeothermal

Anomaly

Vitrinite ReflectanceValues, %Ro

Higley & Cox, 2005

Wattenberg Thermal AnomalyWattenberg Thermal Anomaly

• Related to igneous masses in basement• Located where CMD intersects Denver

Basin• Direct temperature measurements in

wells• Ro values• GORs

• Related to igneous masses in basement• Located where CMD intersects Denver

Basin• Direct temperature measurements in

wells• Ro values• GORs

Modified from Weimer, 1995

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

DEP

TH

0 1000 2000 3000 4000 5000 6000 7000

HYDROSTATIC GRADIENT (0.43 psi/ft)

UNDERPRESSURED

OVERPRESSUREDMigration

Paths

Sussex(Terry)

Shannon(Hygiene)

PierreShale

Muddy J SSBenton Gp.

Sharon Springs MbrNiobraraCodell

SourceRock

Weimer, 1995PRESSURE PSI

Overpressuring in Rockies Basins

INCREASING THERMAL METAMORPHISM

VOLUME OF ORIGINALUNMETAMORPHOSED“IMMATURE ORGANICMATERIAL (KEROGEN)

ASSUMES GENERATED HYDROCARBONS ARERETAINED IN SYSTEM & CONVERT TO

STABLE SPECIES

VOLUME OF METAMORPHOSEDORGANIC MATERIAL

VOLUME OF GENERATEDFLUID HYDROCARBONS

“MATURE”

Modified from Spencer, 1987 and Meissner, 1980SAS, 04

Structural OverviewStructural Structural OverviewOverview Fort

Collins

Greeley

Golden

Denver

7N

5N

1N

3N

1S

3S

5S

64W66W68W

3750

3500

3250

32503000

3000

3000

2500

27.5

275025002000

2500

2500 2750 300

2750

3000

2500150027.510

5

275020

0017

.515

00

2750

2750

3000

2500

3000

3000

J. WFZ

B.H.P.

Longmont

Fault ZoneBe.

RM A

C.G. WFZ

S.L.

W. WFZ

??

N

S

Boulder

Lafayette

Fault Zone

North-trending structural axis

Northeast trending right lateral wrench faults

Antithetic and synthetic horsts and grabens

Contours represent subsea depths to top J SS

Weimer, 2000

T5N

T4N

Codell Faulting Density isGreater than J Sand

Codell Faulting Density isGreater than J Sand

Ladd, 2001

J Sandstone Stratigraphic Nomenclature

J Sandstone Stratigraphic Nomenclature

HuntsmanShale

Mowry Shale

D Sand

8100

8000

7950

7900

Sec 9 2N 67W Sec 31 1N 65W

Skull Creek ‘A’

Skull Creek Marker

Skull Creek Ash

8050

J Sandstone

Skull Creek Shale


LSE/SB

Skull Creek

J SS

TSE / LSE

HuntsmanShale

Horsetooth Member(LST/TST)

8100

8000

7950

7900

Sec 9 2N 67W Sec 31 1N 65W

Skull Creek ‘A’

Skull Creek

Skull Creek Ash

8050

J Sandstone

TSE

LSE

Mowry Shale

Fort CollinsMember

(HST)

D Sand

Sequence Stratigraphy of J Sandstone

Sequence Stratigraphy of J Sandstone

FC1

FC2


T 1

NT

1 S

T 2

NT

3 N

T 4

N

R 68 W R 67 W R 66 W R 65 W R 64 W

EURRed > 15 Bcf / sec.Green 10 - 12 Bcf / sec.Blue < 8 Bcf / sec.

J Sandstone Original Gas in Place

J Sandstone Original Gas in Place

Hu, 2002

A A’

B

B’

Sequence Stratigraphy of Fort Collins Member

Sequence Stratigraphy of Fort Collins Member

0 5000 10000 ft.

100 Ft.

SE11

2N

67W

SW12

2N

67W

SE12

2N

67W

SW7

2N 6

6W

SE7

2N 6

6W

SW8

2N 6

6W

SE8

2N 6

6W

SW9

2N 6

6W

SE9

2N 6

6W

SW10

2N

66W

SE10

2N

66W

SW11

2N

66W

SE11

2N

66W

SW12

2N

66W

SE12

2N

66W

W E

FC 3FC 3FC2FC2

FC 2AFC 2ASkull Creek A

Skull Creek

Mowry Shale

FC 1FC 1

Huntsman Shale(Graneros)

Fort Collins 1

SW10

2N

67W


Kugel 21-18Kugel 21-18

Horsetooth Valley Cross SectionHorsetooth Valley Cross Section

NE2

5 1N

67W

SW19

1N

67W

NE1

9 1N

66W

SW17

1N

66W

NE1

7 1N

66W

NE8

1N

66W

SW4

1N 6

6W

NE4

1N

66W

SE33

1N

66W

NE3

3 2N

66W

SE27

2N

66W

NE2

7 2N

66W

SW NE

0 5000 10000 ft.

100 Ft.

Huntsman Shale(Graneros)

Mowry Shale

Fort CollinsMember

FC3FC3FC2FC2

FC1FC1

FC2AFC2A

Skull Creek A

Skull Creek


R 68 W R 67 W R 66 W R 65 W R 64 W

J Gas Trap Is Stratigraphic(Facies Pinch-out & Muddy Valley-fill)

J Gas Trap Is Stratigraphic(Facies Pinch-out & Muddy Valley-fill)

T 1

NT

1 S

T 2

NT

3 N

T 4

N

A A’

Stacked Stacked FC 1 and FC 2FC 1 and FC 2

B

B’FC

1 str

andli

ne

FC 1

stran

dline

StackedFC 2 & 3

Paleovalley

Paleovalley

Paleovalley

Paleovalley

Paleovalley

Paleovalley

Paleovalleymodified from Hu, 2002; Gustason and Sonnenberg, 2003

J %Ro > 1(blue lineafter Higley& Cox,2005)

Pertinent Data – Muddy J Sandstone, Wattenberg Field

Pertinent Data – Muddy J Sandstone, Wattenberg Field

• Depth 7,600 – 8,400 ft• BHT, oF 260• BHP, psig 2,900• Gross sand, ft 50 to 100• Net pay, ft 10 to 50• Porosity, % 8 to 12• Permeability, md 0.05 – 0.005• Original spacing 320• Est. original reserves 1.3 TCF• Current Est. Cum 1.3 TCF

• Depth 7,600 – 8,400 ft• BHT, oF 260• BHP, psig 2,900• Gross sand, ft 50 to 100• Net pay, ft 10 to 50• Porosity, % 8 to 12• Permeability, md 0.05 – 0.005• Original spacing 320• Est. original reserves 1.3 TCF• Current Est. Cum 1.3 TCF

modified from Matuszczak, 1976

Production“Sweet Spot”

Dome # 1-13 FrankSec. 13-T4N-R65WDome # 1-13 FrankSec. 13-T4N-R65W

Niobrara &Codell Type Log Niobrara &Niobrara &CodellCodell Type Log Type Log

30

30 -10

Dens.Neut.G.R. Resis.

6900

7000

7100

7200

10%

NIOBRARA

FT. HAYES

CODELL

CARLILE

C CHALK

B CHALK

A CHALK

NW SE NW NW SE NW Sec. 8, T3NSec. 8, T3N--R67WR67W


Codell Pressure GradientCodell Pressure Gradient

••Based upon PBased upon P--buildupsbuildups

••Range: 0.366Range: 0.366--0.669 psi/ft.0.669 psi/ft.

••Coincident with basin axisCoincident with basin axis

••Most north of Most north of ““Wattenberg Wattenberg HighHigh””

••Follows J Ro =1% outline Follows J Ro =1% outline (blue)(blue)

••High GOR, sweet spot (gray High GOR, sweet spot (gray area) coincident with area) coincident with temperature anomalytemperature anomaly

Birmingham, 2000

Pertinent Data – CodellSandstone, Wattenberg Field

Pertinent Data – CodellSandstone, Wattenberg Field

• Depth 7,100 – 7,300 ft• BHT, oF 220• BHP, psig 4,600• Gross sand, ft 10-15• Net pay, ft 5-12• Porosity, % 8 to 12• Permeability, md 0.05 – 0.005• Original spacing 80• Est. original reserves NA

• Depth 7,100 – 7,300 ft• BHT, oF 220• BHP, psig 4,600• Gross sand, ft 10-15• Net pay, ft 5-12• Porosity, % 8 to 12• Permeability, md 0.05 – 0.005• Original spacing 80• Est. original reserves NA

Lessons LearnedLessons Learned

• Bypassed pay• Technology• Field growth • Long range migration• Reservoir compartmentalization• LRLC pays• Geothermal anomalies

• Bypassed pay• Technology• Field growth • Long range migration• Reservoir compartmentalization• LRLC pays• Geothermal anomalies

wattenberg field area, a near miss & lessons learned after 35

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