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Mathematical Relations

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This slides shows the proof of new hydraulic flow unit

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Page 1: Mathematical Relations

A New Approach in Hydraulic Flow Unit Determination and its Application

for Prediction of Petrophysical Properties

By: Mohammad Izadi

Supervisor: Dr Ali Ghalambor

Page 2: Mathematical Relations

Contents:

1) Quick Review

2) Mathematical Modeling

3) Future Work

Page 3: Mathematical Relations

Quick Review:

- Reservoir Characterization

- Rock Typing

- Hydraulic Flow Unit

Page 4: Mathematical Relations

Mathematical Modeling

- Poiseuille Equation

Assumptions:

- Steady state flow

- Laminar flow

- One phase flow

- No-slip flow at the wall

- Capillary size tube (micron size

diameter)

1 1p d dr

x r dr dr

υµ

∆ =∆

Page 5: Mathematical Relations

New Assumption:

R r

2 2 2 2

2 2water

wpore

V R L r L R rS

V R L R

π ππ

− −= = = 1 wr R S= −

New Radius and Bundle of capillary tube

Mathematical Modeling (cont.)

Page 6: Mathematical Relations

Mathematical Modeling (cont.)

1 1p d dr

x r dr dr

υµ

∆ =∆

2 21( ) [ (1 ) ]

4 w

pr R S r

µ∆= − −∆

4 21 2 3

0

. . (1 )[ (1 ) ]

2 8

wR Sw

w

p R SprR S r dr

x x

ππµ µ

− ∆ −∆Φ = − − =∆ ∆∫

4 2(1 )

8wp r S

qL

πµ

∆ −=∆

Page 7: Mathematical Relations

ckA pq

Lµ∆=

4 2(1 )

8wn p r S

qL

πµ

∆ −=∆

Coupling of Darcy and Poiseuille Equations

4 2(1 )

8w

c

n r Sk

A

π −=

2p

b c

V n r L

V A L

πφ = =2

c

n rA

πφ

=

Therefore, 2 2(1 )

8wr S

kφ−=

Mathematical Modeling (cont.)

Page 8: Mathematical Relations

Kozeny (1927) defined two following parameters:

2

(2 ) 2

( )P

sV

p

A n rLS

V n r L r

ππ

= = = (internal surface area per unit of pore volume)

2(2 ) 2 1( )

(1 ) (1 )gr

sV

gr c c

A n rL nrS

V A L A r

π πφ φ

= = =− −

(total area exposed within the pore space per unit of grain volume )

Combining equations ( )1gr pV VS S

φφ

=−

Substituting

32

2 2

1(1 )

2 (1 )gr

wV

k SS

φφ

= × × −−

Mathematical Modeling (cont.)

Page 9: Mathematical Relations

Kozeny and Carmen (1937) obtained the following relationship by defining the tortuosity and replacing in Darcy equation:

3

2 2 2

1[ ]

(1 ) 2 gv

kS

φφ τ

=−

The generalized form of Kozeny-Carmen relationship is given by the equation

3

2 2 2

1[ ]

(1 ) s gv

kF S

φφ τ

=−

Fs : Shape Factor, 2 for circular cylinder

2sFτ : Kozeny constant

Mathematical Modeling (cont.)

Page 10: Mathematical Relations

With the analogy to previous equations

32

2 2 2

1(1 )

(1 )gr

ws V

k SF S

φτ φ

= × × −−

To define the HFU model we need to rearrange the equation to:

We propose two approaches and define new terms.

Mathematical Modeling (cont.)

Page 11: Mathematical Relations

Approach 1 1 1

(1 ) (1 ).grw s V

k

S F S

φφ φτ

× = ×− −

Approach 2 (1 )1

(1 ).gr

w

s V

Sk

F S

φφ φτ

−= ×−

1

(1 )w

k

Sφ×

− Modified Reservoir Quality Index (MRQI).

1

.grs VF Sτ

Flow Zone Indicator (FZI)

(1 )

φφ−

Normalized Porosity

k

φReservoir Quality Index (RQI)

(1 )

(1 )wSφ

φ−− Modified Normalized Porosity

Mathematical Modeling (cont.)

Page 12: Mathematical Relations

Future Work

1) Completing Routine and Special Core Analysis

2) Applying available data to proposed models and

comparing to the existing model

3) Up scaling with log analysis

Page 13: Mathematical Relations

Thank you!

Questions?