1 8/14/2012

Effective evaluation for optimal completion

Tom Neville

Shale reservoirs

2 8/14/2012

Gas resource triangle

Holditch, 2006

3 8/14/2012

Continuum of unconventional gas resources

Tight

gas

Gas

shale

Coal seam

gas

Increasing organic content

Increasing adsorbed gas

Increasing pore throat size

Increasing free gas

Increasing matrix permeability

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Shales ≠ shales ≠ shales

Miller et al., 2010

5 8/14/2012

Shales ≠ shales ≠ shales

Based on data from Curtis, 2002

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The one common feature of all shale plays

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Optimising unconventional gas production

Understanding of

■ reservoir quality

― hydrocarbon potential

― hydrocarbon in place and

matrix deliverability

■ completion quality

― stimulation potential

― effectiveness to create and

maintain maximum fracture

surface area

8 8/14/2012

Optimising unconventional gas production

Understanding of

■ reservoir quality

― hydrocarbon potential

― hydrocarbon in place and

matrix deliverability

■ completion quality

― stimulation potential

― effectiveness to create and

maintain maximum fracture

surface area

9 8/14/2012

Reservoir quality

Hydrocarbon potential

■ Hydrocarbon-in-place and deliverability

― Organic content and type

― Thermal maturity

― Effective porosity

― Fluid saturations

― Gas in place

― Permeability

― Reservoir pressure

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Source, reservoir, trap, and seal

11 8/14/2012

Source, reservoir, trap, and seal

12 8/14/2012

Source, reservoir, trap, and seal

Jarvie et al., 2007

13 8/14/2012

Unconventional gas volumetrics

Milner et al., 2010

14 8/14/2012

Unconventional gas volumetrics

Mat

rix

Fre

e ga

s

Fre

e w

ater

Cla

y-bo

und

wat

er

Ash

(mat

rix)

Moi

stur

e

(fre

e w

ater

) (c

lay-

boun

d w

ater

)

Fix

ed c

arbo

n

(ker

ogen

)

Vol

atile

s

(ads

orbe

d ga

s)

Mat

rix

Oil

in la

rge

pore

s

Fre

e ga

s

Fre

e w

ater

Cla

y-bo

und

wat

er

Ker

ogen

Bitu

men

Ads

orbe

d ga

s

15 8/14/2012

Milner et al., 2010

The importance of organic matter

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Gas storage associated with organic matter

Alexander et al., 2011

17 8/14/2012

Reservoir quality associated with organic matter

Lewis, 2010 Passey et al., 2010

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Correlating to TOC

Schmoker, 1979; Schmoker and Hester, 1983; Hester and Schmoker, 1987; Hester et al., 1990; Schmoker, 1993

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Looking for TOC’s “shadow”

Hook et al., 2011 Passey et al., 1990; Passey et al., 2010

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Measuring TOC directly

Water-Based Mud Oil-Based Mud

TOC TOC TOC TOC

Herron, 1986; Herron et al., 2011; Radtke et al., 2012

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Core analysis for reservoir quality

■ Petrographic analysis ― X-ray diffraction

― Thin section microscopy

― Scanning electron microscopy

■ Organic matter characterisation ― TOC

― RockEval pyrolysis

― Vitrinite reflectance

■ Petrophysical measurements ― Bulk and grain density

― Total porosity and gas-filled porosity

― Total water saturation and clay bound water saturation

― Gas and oil saturations

― Permeability

■ Gas-in-place estimation ― Canister desorption

― Adsorption isotherm analysis

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Sampling for representative core analysis

23 8/14/2012

Rock typing for shale evaluation

Suarez-Rivera et al., 2008

24 8/14/2012

Integrated reservoir quality analysis

Boyer et al., 2006

25 8/14/2012

Optimising unconventional gas production

Understanding of

■ reservoir quality

― hydrocarbon potential

― hydrocarbon in place and

matrix deliverability

■ completion quality

― stimulation potential

― effectiveness to create and

maintain maximum fracture

surface area

26 8/14/2012

Completion quality

Stimulation potential

■ Effectiveness to create and maintain maximum fracture surface area

― Vertical hydraulic fracture containment

― Rock fracturability

― Mechanical properties

― Near wellbore and far-field stresses

― Mineralogy, particularly clay type and content

― Fluid sensitivity

― Propensity for solids production

― Presence, orientation, and nature of natural fractures

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Anisotropy at many length scales

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Transverse isotropic media

■ Isotropic media

― Same property in the 3 principal directions of space

■ Transverse isotropic

― Property is the same in 2 principal directions:

TIV same property in horizontal plane

TIH same property in vertical plane

■ Orthotropic

― Property varies in 3 directions

X Y

Z

X Y

Z

X Y

Z

X Y

Z

Isotropic

TIV

TIH

Orthotropic

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Anisotropic mechanical properties

Suarez-Rivera et al., 2011

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11 12 13

12 11 13

13 13 33

44

44

66

0 0 0

0 0 0

0 0 0

0 0 0 0 0

0 0 0 0 0

0 0 0 0 0

xx xx

yy yy

zz zz

xz xz

yz yz

xy xy

C C C

C C C

C C C

C

C

C

Core Testing Advanced acoustics

661112

2

stoneley_shear

h

hh66

2

s_fast

2

s_slow

v

vv5544

2

p

vv

vvv33

C2CC

V)1(2

EGC

VV)1(2

EGCC

V)21)(1(

)1(EMC

Anisotropic geomechanics

Higgins et al., 2008

31 8/14/2012

Anisotropic model closure stress estimate

Isotropic model closure stress estimate

Litho-static

component

Pore-elastic

component Tectonic component

Litho-static

component

Pore-elastic

component Tectonic component Anisotropy

component

Anisotropic geomechanics

Thiercelin & Plumb, 1994

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Impact of anisotropy on completion design

Isotropic stress model

Fracture length &

height

Stress

profile Fracture

width

2000’

Anisotropic stress model

Fracture length &

height

Stress

profile Fracture

width

1500’

Waters et al., 2011

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Impact of anisotropy on completion design

Goodwin et al., 2010

34 8/14/2012

Relationship between stress and fracture orientation

min

max

PFP

35 8/14/2012

Relationship between stress and fracture orientation

Tensile Shear

max

PFP

36 8/14/2012

Core analysis for completion quality

■ Petrographic analysis

― X-ray diffraction

― Thin section microscopy

― Scanning electron microscopy

■ Mechanical properties determination

― Multistress compression testing

■ Rock-fluid interaction

― Proppant embedment

― Permeability reduction

― Fluid compatibility

■ Core fracture analysis

37 8/14/2012

Integrated completion quality analysis

Tollefsen et al., 2010

38 8/14/2012

Optimising unconventional gas production

Understanding of

■ reservoir quality

― hydrocarbon potential

― hydrocarbon in place and

matrix deliverability

■ completion quality

― stimulation potential

― effectiveness to create and

maintain maximum fracture

surface area

39 8/14/2012

Sub-optimal completions

Miller et al., 2011, SPE

40 8/14/2012

Optimal completions

Miller et al., 2011, SPE

41 8/14/2012

Effective evaluation for optimal completion

Geology

Reservoir

engineering

Petrophysics Geomechanics

Reservoir quality

Completion quality

42 8/14/2012

References

■ Alexander, T.; Baihly, J.; Boyer, C.; Clark, B.; Waters, G.; Jochen, V.; Le Calvez, J.; Lewis, R.; Miller, C. K.; Thaeler, J. & Toelle, B. E., 2011: Shale gas revolution. Oilfield Review, 23, 3, p 40-55.

■ Boyer, C.; Kieschnick, J.; Suarez-Rivera, R.; Lewis, R. E. & Waters, G., 2006: Producing gas from its source. Oilfield Review, 18, 3, p 36-49.

■ Curtis, J. B., 2002: Fractured shale-gas systems. American Association of Petroleum Geologists Bulletin, 86, 11, p 1921-1938.

■ Goodwin, S.; Higgins, S.; Bratton, T.; Donald, A.; Tracy, G. & Yuen, F., 2010: Anisotropy key for Baxter Shale wells. The American Oil & Gas Reporter, 4 p.

■ Herron, S., 1986: A total organic carbon log for source rock evaluation. 27th Annual Logging Symposium, paper HH, 12 p.

■ Herron, M. M.; Grau, J. A.; Herron, S. L.; Kleiberg, R. L.; Machlus, M.; Reeder, S. L.; Vissapragada, B.; Burnham, A. K.; Day, R. L. & Allix, P., 2011: Total organic carbon and formation evaluation with wireline logs in the Green River oil shale. SPE Annual Technical Conference and Exhibition, paper SPE 147184-MS, 19 p.

■ Hester, T. C. & Schmoker, J. W., 1987: Determination of organic content from formation-density logs, Devonian-Mississippian Woodford Shale, Anadarko Basin, Oklahoma. United States Geological Survey Open-file report, 87-20.

■ Hester, T. C.; Schmoker, J. W. & Sahl, H. L., 1990: Log-derived regional source-rock characteristics of the Woodford Sahel, Anadarko Basin, Oklahoma. D Evolution of sedimentary basins--Anadarko Basin, United States Geological Survey, U.S. Geological Survey Bulletin, 1866D, 38 p.

■ Higgins, S.; Goodwin, S.; Donald, A.; Bratton, T. & Tracy, G., 2008: Anisotropic stress models improve completion design in the Baxter Shale. 2008 SPE Annual Technical Conference and Exhibition, paper SPE 115736-MS, 10 p.

■ Holditch, S. A., 2006: Tight gas sands. Journal of Petroleum Technology, p 84-90, paper SPE 103356-PA.

■ Hook, P.; Fairhurst, D.; Rylander, E.; Badry, R.; Bachman, N.; Crary, S.; Chatawanich, K. & Taylor, T., 2011: Improved precision magnetic resonance acquisition: application to shale evaluation. SPE Annual Technical Conference and Exhibition, paper SPE 146883-MS, 8 p.

■ Jarvie, D. M.; Hill, R. J.; Ruble, T. E. & Pollastro, R. M., 2007: Unconventional shale-gas systems: the Mississippian Barnett Shale of north-central Texas as one model for thermogenic shale-gas assessment. American Association of Petroleum Geologists Bulletin, 91, 4, p 475-499.

■ Lewis, R., 2010: What makes a good gas shale? Presentation given to the Mid-Continent Section of the Society of Petroleum Engineers.

■ Miller, C.; Rylander, E. & Le Calvez, J., 2010: Detailed rock evaluation and strategic reservoir stimulation planning for optimal production in horizontal gas shale wells. Search and Discovery, article 90108.

■ Miller, C.; Waters, G. & Rylander, E., 2011: Evaluation of production log data from horizontal wells drilled in organic shales. SPE North American Unconventional Gas Conference and Exhibition, paper SPE 144326-MS, 23 p.

■ Milner, M.; McLin, R. & Petriello, J., 2010: Imaging texture and porosity in mudstones and shales: comparison of secondary and ion-milled backscatter SEM methods. Canadian Unconventional Resources \& International Petroleum Conference, paper CSUG/SPE 138975-MS, 10 p.

■ Passey, Q.; Creaney, S.; Kulla, J.; Moretti, F. & Stroud, J., 1990: A practical model for organic richness from porosity and resistivity logs. American Association of Petroleum Geologists Bulletin, 74, 12, p 1777-1794.

■ Passey, Q.; Bohacs, K.; Esch, W.; Klimentidis, R. & Sinha, S., 2010: From oil-prone source rock to gas producing shale reservoir - geological and petrophysical characterization of unconventional shale-gas reservoirs. CPS/SPE International Oil & Gas Conference and Exhibition in China, paper SPE 131350-MS, 29 p.

■ Radtke, R.; Lorente, M.; Adolph, B.; Berheide, M.; Fricke, S.; Grau, J.; Herron, S.; Horkowitz, J.; Jorion, B.; Madio, D.; May, D.; Miles, J.; Perkins, L.; Philip, O.; Roscoe, B.; Rose, D. & Stoller, C., 2012: A new capture and inelastic spectroscopy tool takes geochemical logging to the next level. SPWLA 53rd Annual Logging Symposium, paper AAA, 16 p.

■ Schmoker, J. W., 1979: Determination of organic content of Appalachian Devonian Shales from formation-density logs. American Association of Petroleum Geologists Bulletin, 63, 9, p 1504-1537.

■ Schmoker, J. W., 1993: Use of formation-density logs to determine organic-carbon content in Devonian shales of the western Appalachian Basin and an additional example based on the Bakken Formation of the Williston Basin. Chapter J in Roen, J. B. & Kepferle, R. C. (Eds.) Petroleum geology of the Devonian and Mississippian black shale of eastern North America, United States Geological Survey, U.S.Geological Survey Bulletin, 1909, 14 p.

■ Schmoker, J. W. & Hester, T. C., 1983: Organic carbon in Bakken Formation, United States portion of Williston Basin. American Association of Petroleum Geologists Bulletin, 67, 12, p 2165-2174.

■ Suarez-Rivera, R.; Handwerger, D. A.; Sodergren, T. L. & Green, S. J., 2008: Method and apparatus for multi-dimensional data analysis to identify rock heterogeneity. Patent application US 2008/0162098 A1.

■ Suarez-Rivera, R.; Deenadayalu, C.; Chertov, M.; Hartanto, R. N.; Gathogo, P. & Kunjir, R., 2011: Improving horizontal completions on heterogeneous tight shales. Canadian Unconventional Resources Conference, paper CSUG/SPE 146998-MS, 21 p.

■ Thiercelin, M. and Plumb, R., 1994: Core-based prediction of lithologic stress contrasts in east Texas formations. SPE Formation Evaluation, 9, 4, 251-258, paper SPE 21847-PA.

■ Tollefsen, E.; Perry, A.; Kok, J.; Alford, J.; Han, S. Y.; Malpani, R. & Baihly, J., 2010: Unlocking the secrets for viable and sustainable shale gas development. SPE Eastern Regional Meeting, paper SPE 139007-MS, 21 p.

■ Waters, G. A.; Lewis, R. E.; Bentley, D. C. & Kelley, J., 2010: The effect of mechanical properties anisotropy on the generation of hydraulic fractures in organic shales. SPE Annual Technical Conference and Exhibition, paper SPE 135626-MS, 24 p.

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Milner et al., 2010