SLB NMR Clay Brine Slides

7/27/2019 SLB NMR Clay Brine Slides

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NMR Relaxation

of Clay-Brine Mixtures

Abigail Matteson, Joseph Tomanic,

Michael Herron, David Allen andWilliam KenyonSchlumberger-Doll Research


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2

T2 (ms)

0.03 3.0 33 30000.3

Small pore water Capillary

bound

water

Free-fluid porosity

Producible fluids

3-ms porosity

Total CMR porosity

Sandstone T2 Distribution

Signaldistribution


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3

Transverse Relaxation Equation

Surface relaxation

Bulk fluid relaxation

Diffusion in field gradient

relaxation

1T2S

=

1

T2B=

1

T2D

=

1

T2

1

T2S

1

T2B T2D= + +

1


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Surface Relaxation Equation

r2 = Surface relaxivityS = Surface area

Vp = Pore volume

1T2S

SVp

=

2r


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T2 Response of

Clay-Bound Water

T2 (ms)

Clay particles

Bound

water

Air

Signaldistribution


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T2 Response of

Clay-Bound Water and Brine

slow Molecular diffusion fast

Clay particlesBoundwater

Brine

Signal

distribution

T2 (ms) T2 (ms)


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Objective of Study

l clay-bound water

l clay type andl pore-size distribution?

Can a T2

distribution be used to

measure


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Experimental Setup

l Maximize the amount of clay-bound water

l Use various clay types

Kaolinite, smectite, illite and glauconite

l Vary pore volume Compact clay-brine mixtures (max 16,000 psi)

l Measure T2

distributions

Clays, clay-brine mixtures


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9

Clay Types and PropertiesClay CEC

(meq/100 g)

Magnetic

susceptibility(micro cgs, 10-6)

Fe2O3(wt%)

Kaolinite

Warren Co., Georgia

17.310.9 0.5 1.0

Illite

Fithian, Illinois

97.816.0 8.6 9.2

Texas

Smectite 62.282.6 1.8 1.2

Glauconite

Birmingham, New Jersey

72.321.4 21.7 22.2

Surface area(m2/g)


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T2 Response of

Clay-Bound Water

T2 (ms)

Clay particles

Bound

water

Air

Signaldistribution


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Clay T2 Distributions at

Room Humidity Conditions

T2 (ms)

0

0.02

0.04

0.06

0.08

0.1 1.0 10 100 1,000 10,000

Smectite

Illite

Glauconite

Kaolinite


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Smectite

0.1 1.0 10 100 1,000 10,000

T2 (ms)

0

0.50

0.70

1.00

1.20

2.50

30

20

20

20

14Slurry

8 psi

27 psi

89 psi)

500 psi

1,000 psi

2,000 psi

4,000 psi

8,000 psi

16,000 psi


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Illite

0.1 1.0 10 100 1,000 10,000

T2 (ms)

0

0.50

10

20

40

60

60

80

80

80

30Slurry

8 psi

23 psi

78 psi)

500 psi

1,000 psi

2,000 psi

4,000 psi

8,000 psi

16,000 psi


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T2 Peak Positions

0.1 1.0 10 100 1,000 10,000

T2 (ms)

8-11 psi

500 psi

16,000 psi

Glauconite

Illiite

Smectite

Kaolinite


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Surface Relaxation Equation

r2 = Surface relaxivityS = Surface area

Vp = Pore volume

1T2S

SVp

=

2r


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4

0

1

2

3

0 5000 10,000 15,000 20,000

Pressure (psi)

r2 (mm/s)

KaolinitePressure Versus Surface Relaxivity (r2)


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Iron Concentration VersusSurface Relaxivity (r2)

Fe2O3 (wt%)

4

0 5 10 15 20 25

Kaolinite

0

1

2

3

Illite

Kaolinite

Smectite Glauconite

r2 (mm/s)


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0

5

10

0 50 100

Cation exchange capacity(meq/g)

Log-mean

T2

(ms)

Kaolinite

Smectite

Illite

Glauconite

CEC Versus Log-Mean T2


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Shale 1

T2 (ms)

0

2

4

6 40% Illite

0% Smectite

21% Kaolinite

0% Chlorite

4% Glauconite

0.1 1.0 10 100 1000 10,000

3 ms


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5

15

25

35

40% Illite

7% Smectite

14% Kaolinite

0% Chlorite

0% Glauconite

Shale 2

T2 (ms)

0.1 1.0 10 100 1000 10,000

3 ms


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Objective of Study

l clay-bound water

l

clay type andl pore-size distribution?

Can a T2 distribution be used to

measure


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Conclusionsl T2 distributions have a single peak.

Cannot measure clay-bound water Implies fast diffusion between clay-bound

and pore waters

l T2 peak position is a function of

Clay type

Compaction and clay concentration (S/Vp)

Surface relaxivity (varies with iron

content).Cannot identify clays

l T2 peak position is not a function of CEC.

SLB NMR Clay Brine Slides

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