linear flow systems

7/28/2019 Linear Flow Systems

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1Linear Flow Systems

For

The RPI Users Group

BJ Services

Conference Room

May 21, 1998

Copyright Performance Sciences, Inc. - 1999. All Rights Reserved


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Types of Systems:

1.Bar Sand Environments

Lake Uintah south shore

2.Channel Sand Environments

Morrow/Springer Channels

Red Fork

D Sand2



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Naturally Fractured Reservoirs3

Sparsely Fractured

Moderately Fractured (Compartmentalized)

Intensely Fractured (approaching Radial Flow)



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Theory:4


ct

khxqt

f

s

s

wi

= )(


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An Example:5

K = .25 mDs. Xe = 200 ft. Xf = 50 ft. Ad = .9183 Ac.


Production History

0

100

200

300

400

500

600

0 10 20 30 40 50 60 70 80 90 100

Elapsed Time (Days)

GasRate(MCF/D)

0

500

1000

1500

2000

2500

3000

BackPressure(PSIA)

Rate

Pressure


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The MDH Plot:

6


RPI - MDH

BaseCase - Linear Flow

0

200

400

600

800

1000

1200

1400

1600

1800

2000

-1.5 -1 -0.5 0 0.5 1 1.5 2 2.5

Log of Elapsed Time (Days)

ReciprocalProductivityIndex

Drawdown

Permeability =

Skin =

0.255

0.52


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The Root Plot

7


Square Root Plot

0

100

200

300

400

500

600

700

800

900

1000

0 1 2 3 4 5 6

Square Root of Elapsed Time

RPI


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The Agarwal Gringarten Type Curve

8


Agarwal - Gringarten Type Curve


0.10

1.00

10.00

100.00

0.10 1.00 10.00 100.00 1000.00

Dimensionless Time

DimensionlessPressure


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A Compartment Response:

9

K=.25 mDs. xe=200 ft. xf=50 ft. Blk Bdry=75 ft. Threshhold Pressure = 200 psi.


Agarwal - Gringarten Type Curve


0.10

1.00

10.00

100.00

0.10 1.00 10.00 100.00 1000.00

Dimensionless Time

DimensionlessPressure


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10Fig. 3 Production Decline Curve for Expl. #3 Boundary



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Fig. 1 Agarwal-Gringarten Type Curve for Expl. #3 Boundary11



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12Fig. 2 RPI-MDH Plot for Expl. #3 Boundary



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Conclusions:

Geologically controlled linear flow regimes can beevaluated

Use the MDH plot at early time to estimatepermeability

Use Root Plot and AGTC to evaluate length offracture face

Expectations created by assumed radial flow cause

frequent disappointing completions13


linear flow systems

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