depositional facies and petrophysical analysis of the bakken

Depositional Facies and Petrophysical Analysis of the Bakken Formation, Parshall

Field, Mountrail County, North Dakota

Andrea SimensonColorado School of Mines

November 18, 2010

Acknowledgements

Dr. S. A. Sonnenberg Dr. J. F. Sarg Dr. M. Prasad Robert Cluff Discovery Group Fellow Bakken students

Outline Introduction

• Study area, data set, etc. Core Results

• Facies descriptions• Environment of deposition

Well Log Analysis• Model used• Results and mapping

Source-Rock Characteristics• Organic richness & thermal maturity

Conclusions

Lear Pet Expl Parshall SD 1Sec. 3-T152N-R90W

Lodgepole

Ba

kken

Upper Shale

Middle Mbr.

Lower Shale

Three Forks “Sanish”

“Sanish”

“False Bakken”

CSM consortium, Nov 2008

Limit LowerBakken Shale

Limit MiddleBakken

Limit Bakken

1970-80sUpper Bakken Shale Depositional Edge

PlayPost 1987

Horizontal Play

AntelopeField

Sanish & Bakken1953

Elm Coulee2001-P

Horizontal Middle Bakken

Structure Bakken Formation

BakkenSanish

The Bakken Cycles

Robinson Lake & Parshall Field Area

2006-P

CSM consortium, Nov. 2008

Study Area

Modified from LeFever (2008)

Study Area Dataset

T. 147-164N R. 84-99W: 5,700 mi2

Approximately 900 vertical wells with Bakken penetrations, 135 wells with digital logs

10 cores from the NDGS and Fidelity

249 source rock samples, 28 from Parshall Field

Objective and Purpose

Understand the depositional environment of the BakkenFormation in the Parshall Field area

Determine the reservoir quality by applying an integrated petrophysicalanalysis approach

Methods

Detailed core descriptions Lithology, environment of deposition,

reservoir properties, mapping Build petrophysical model using

digital logs available Source rock analysis: organic

richness, thermal maturity, etc.

Core Descriptions

Facies identification and description

Log calibration

Core Locations

Facies C1 & C2(10,102 – 10,119 feet)(3,079.1 – 3,084.3 meters)

Facies A(10,142 – 10,146 feet)(3,091.3 – 3,092.5 meters)

Facies B(10,119 – 10,142 feet)(3,084.3 – 3,091.3 meters)

Facies D1 & D2(10,084 – 10,102 feet)(3,073.6 – 3,079.1 meters)

Facies G(10,146 – 10,192 feet)(3,092.5 – 3,106.5 meters)

Facies G(10,077 – 10,077 feet)(3,071.5 – 3,071.5 meters)

Facies E1, E2 & F(10,077 – 10,084 feet)(3,071.5 – 3,073.6 meters)

L. Bakken

M. Bakken

U. Bakken

Deadwood Canyon Ranch #43-28H

Middle Bakken Facies

Facies A

Muddy lime wackestone Crinoid and brachiopod

shell fragments common Common burrows Absence of waves and

currents Suspension deposition,

deposit-feeder traces

From Long #1-01H9,171.9 ft (2,795.6 m)


Facies B

Bioturbated, argillaceous, calcareous, very fine-grained sandstone/siltstone

Helminthopsis/Sclaritubadominant trace fossils

Possible Planolites Sparse bivalves Local calcareous

concretions Sparse calcite-filled

vertical fractures From N & D #1-05H9,447.0 ft (2,879.4 m)


Facies C1

Planar to undulose and discontinuous laminated, shaly, very fine-grained siltstone/sandstone

Crenulated/irregular bedding surfaces may be influenced by microbial activity

Local calcareous concretions

From Deadwood Canyon Ranch #43-28H10,112.7 ft (3,082.4 m)


Facies C2

symmetrically ripple to undulose laminated, very fine-grained siltstone/sandstone

Local bioturbation Possible hummocky cross

stratification present

From Deadwood Canyon Ranch #43-28H

10,103.8 ft (3,079.6 m)

From Van Hook #1-13H9,470.8 ft (2,886.7 m)


Facies D1

Contorted to massive fine-grained sandstone

Local soft sediment deformation

Common micro-faults and calcite-filled fractures

From Dobrinski #18-448,653.2 ft (2,637.5 m)


Facies D2

Low angle, planar to slightly undulose, cross laminated sandstone with thin discontinuous shale laminations

Highly calcareous Some calcite-filled

fractures



Facies E1

Finely inter-laminated, bioturbated, dolomitic-mudstone and dolomitic siltstone/sandstone

Local contorted bedding and soft sediment deformation

Crenulated/irregular bedding surfaces may be influenced by microbial activity

Local ripples and possible hummocky cross stratification From Long #1-01H

9,146.0 ft (2,787.7 m)


Facies E2

Calcitic, whole fossil, dolomitic-to lime wackestone

Fossil rich beds contain crinoid fragments and brachiopods found as articulated shells, single valves, or shell fragments

Found interspersed with facies E1

From Fertile #1-12H9,372.5 ft (2,856.7 m)



Facies F

Bioturbated, shaly, dolomitic siltstone

Sometimes mottled looking

Local beds of homogeneous/ planar laminated dolomiticsiltstone

From Jensen #12-449,170.1 ft (2,795.0 m)

Upper and Lower Bakken Facies

Facies G

Organic rich, pyritic, brown/black mudstone

Planar laminated Horizontal and

vertical fractures cemented with calcite and pyrite

Local thin sideriticbeds, sparsely burrowed

Upper Bakken

Lower Bakken


10,174.0 ft (3,101.0 m)

From Long #1-01H9,135.0 ft (2,784.3 m)

Environment of Deposition

A

B

C D

E

F

Modified from Smith and Bustin (1996)

HST

LST

TST

Deadwood Canyon Ranch #43-28H

Upper Bakkenmfs

mfs

E and Fts

SBD

TST

LST

HST

C

B

A

Lower Bakken

Stratigraphic cross section grid shown on the Middle Bakken isopach map

West to east stratigraphic section with the Upper Bakken as the datum

Lower Bakken and Facies C,B,A thinning to the east

Facies D not present in all of the wells

Facies A and B

From Long #1-01H9,171.9 ft (2,795.6 m)

A

B

From N & D #1-05H9,447.0 ft (2,879.4 m)

Facies C


C1

C2


10,103.8 ft (3,079.6 m)


Facies D

D1

D2

From Dobrinski #18-448,653.2 ft (2,637.5 m)


10,094.7 ft (3,076.9 m)

Facies E and F

From Jensen #12-449,170.1 ft (2,795.0 m)

From Fertile #1-12H

9,372.5 ft (2,856.7 m)

From Long #1-01H

9,146.0 ft (2,787.7 m)

E2

F

E1

Well Log Analysis

Logs• GR• Resistivity• Acoustic Compressional

and Shear• Density• Neutron

Formation Tops

Core Data• Porosity• Grain density• Gas permeability• Permeability to air• Water saturation• Oil saturation

Deadwood Canyon Ranch #43-28H Type Well

Calculate Sw and BVW

Archie’s Water Saturation equation• a=1; n=1.74;

m=varied by facies• Rw = 0.02• Rt = Deep Resistivity

n

tm

w

RaRSwφ

=

Bulk Volume Water• Used Total Method wT SPHIXBVW *=

Calculate Permeability

Used a generalized form of the Timur Model for permeability calibrated with core data

KSWIEXP

KPHIEXP

coef SWIPHIXKK =log

62500=coefK

VariedKKPHIEXP =

0.2=KSWIEXPK

by facies

Facies E & F

Facies D

Facies C

Facies B

Facies A

m=1.75 KPHIEXP = 4.8





For all faciesa=1 ; n=1.74

Average Sw for the Middle Bakken

Net pay determination

Net feet of pay for the Middle Bakken

Source Rock Richness

Determination of total organic carbon (TOC)

Schmoker and Hester (1983) method using formation density

Passey et al. (1990) method using formation density

261.574.154−

=

ρTOC

( ) ( )LOMRTOC ×−×∆= 1688.0297.210log

TOC ComparisonSanish Field Parshall Field

Upper Bakkenaverage TOCusing the Schmoker and Hester equation

Lower Bakkenaverage TOCusing the Schmoker and Hester equation

Source Rock Type

Published data from Webster (1984) and Price et al. (1984), Parshall data from NDGS

Source Rock Maturity

Published data from Webster (1984) and Price et al. (1984), Parshall data from NDGS

Conclusions Middle Bakken has 9 distinct facies representing a

offshore to tidally influenced inner shelf environment

Good correlation between core facies identified and their corresponding log characteristics

Good correlation between core and log porosity Well log analysis suggest that a variable m works

for a better water saturation model Variable KPHIEXP gets a better permeability

model

Conclusions Water saturations are low in Parshall Field and

increase along the eastern and southern edges of the field

Middle Bakken net pay interval averages 25 feet thick in Parshall and mainly consists of facies E1, C2, C1, and B

Calculated TOC values show an average of 12% in the Upper Bakken and 13% in the Lower Bakken

Rock-Eval data indicates the Bakken is mainly a Type II kerogen in Parshall

Questions?

References

LeFever, J., 2008, What’s Happening at Parshall, North Dakota: North Dakota Geological Survey Newsletter, v. 35, no. 1, p. 1-2.

Nordeng, S. H., and J. LeFever, 2008, The Bakken: A question of maturity: 16th Annual Williston Basin Petroleum Conference, North Dakota Geological Survey, PowerPoint presentation.

Nordeng, S. H., 2010, The Bakken source system: Emphasis on the Three Forks Formation: 18th

Williston Basin Petroleum Conference and Expo, North Dakota Geological Survey, PowerPoint presentation.

Passey, Q. R., S. Creaney, J. B. Kulla, F. J. Moretti, and J. D. Stroud, 1990, A practical model for organic richness from porosity and resistivity logs: AAPG Bulletin, v. 74, no. 12, p. 1777-1794.

Price, L. C., T. Ging, T.Daws, A. Love, M. Pawlewicz, and D. Anders, 1984, Organic metamorphism in the Mississippian - Devonian Bakken shale, North Dakota portion of the Williston Basin inWoodward J., F. F. Meissner, J. L. Clayton, eds., Hydrocarbon Source Rocks of the Greater Rocky Mountain Region, Denver, Colorado, Rocky Mountain Association of Geologists, p. 83-134.

Schmoker, J. W., and T. C. Hester, 1983, Organic carbon in the Bakken Formation, United States portion of Williston basin: AAPG Bulletin, v. 67, no. 12, p. 2165–2174.

Smith, M. G., and R. M. Bustin, 1996, Lithofacies and paleoenvironments of the Upper Devonian and Lower Mississippian Bakken Formation, Williston Basin: Bulletin of Canadian Petroleum Geology, v. 44, p. 495-507.

Webster, R. L., 1984, Petroleum source rocks and stratigraphy of the Bakken Formation in North Dakota in Woodward J., F. F. Meissner, J. L. Clayton, eds., Hydrocarbon source rocks of the greater Rocky Mountain region, Rocky Mountain Association of Geologists, p. 57 - 82.

depositional facies and petrophysical analysis of the bakken

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