Core Analysis

Porosity -permeability correlation (data from Darling, 2005) Core data: Core description

Porosity and permeability from Conventional Core Analysis

Depth in m

Lithology

Depth in m

plug porosity

kh in md

616.0 ... 622.5

shale

622.5 ... 625.0 625.0 ... 626.5 626.5 ... 637.5

sandstone limestone sandstone

0.020 0.020 0.111

0.01 0.02 22

637.5 ... 639.0 639.0 ... 652.0

shale sandstone

620 622 624 626 628 630 632 634 636 638 640 642

plug porosity

0.010 0.095 0.156 0.150 0.075 0.105 0.060 0.179 0.156

10.5 135.6 120 11 15.3 0.8 350 130

Plot permeability versus porosity:

1000

100

   d   m   n    i    h    k

10 sand limes

1

0.1

0.01 0.010

y = 553577.73x4.50 R² = 0.98

0.100 phi

1.000

kh in md

0.03

note: the data point for limestone is eliminated for regression

Derived regression:

k h  5.54  10 5   4.5 where permeability is in md and porosity as fraction

stone tone

Capillary Pressure Curves (data from Darling, 2005) Core data (SCAL):

System: Sample porosity phi permeability k

Air-Brine 1 0.131 67

Pressure Pc in psi 3 10 25 50 125 200

System: Sample porosity phi permeability k

Air-Brine 4 0.179 278

Pressure Pc in psi 3 10 25 50 125 200

Sw 0.861 0.617 0.388 0.290 0.239 0.216

0.730 0.430 0.282 0.214 0.176 0.144

a) Capillary Pressure Curve (laboratory data air-brine) in 200

 .    i   s   p   n    i   c    P

150 100 50 0 0.0

0.5 Sw

c) Water saturation from Capillary Press Curve versus elevation above FWL in  .   m

200.00

  n    i    l   e   v   e    l   r   e    t   a   w   e   e   r    f   e   v   o    b   a

150.00 100.00 50.00 0.00 0.0

0.5 Sw

Conversion from air-brine (laboratory) to kerosene-brine (reservoir) Depth of FWL (m) = 646 Parameter: s cos Q System  Air/Brine 72 Kerosene/Brine 26 Capillary pressure in kPa air-brine 20.68 68.94 172.35 344.70 861.75 1378.80

kerosene/brine 7.47 24.90 62.24 124.48 311.19 497.90

Capillary pressure in kPa air-brine 20.68 68.94 172.35 344.70 861.75 1378.80

kerosene/brine 7.47 24.90 62.24 124.48 311.19 497.90

elevation

depth

above FWL in m 4.39 14.64 36.61 73.22 183.05 292.88

in m 641.61 631.36 609.39 572.78 462.95 353.12

elevation above FWL in m 4.39 14.64 36.61 73.22 183.05 292.88

depth in m 641.61 631.36 609.39 572.78 462.95 353.12

b) Capillary Pressure Curve (converted to kerosene-brine) in kPa

si

1.

500.00   r   r    i  ,   w    S     w    S

400.00

1

 .   a    P    k   n    i   c    P

4

1

300.00

4

200.00 0.

100.00 0.00 0.0

1.0

0.5 Sw

 

ure

d) Water saturation from Capillary Pressure Curve versus depth in m 350.00 400.00

1.0

 .

1

450.00

  m   n    i    l 500.00    h    t   p 550.00   e    d

4

4

600.00

1.0

650.00 0.0

0.5 Sw

1.0

Analyse using Leverett function

 J  ( Sw)   Pc ( Sw ) 

k 

Analyse using Thomeer's equation

1



V b, Pc

  s   cos Q

V b, P  Sw,irr = 0.05 J-function calculated Sw-Sw,irr 0.811 0.567 0.338 0.240 0.189 0.166

e

G   P    log c    P d   

Input parameters

from laboratory data (in kPa) air-brine kerosine-brine 0.94 6.50 3.14 21.65 7.85 54.14 15.71 108.27 39.26 270.68 62.82 433.08

(iterative approximation) sample 1 G -1.5 p d  in psi 1

V b , 

0.12

V b , pc 0.12

0.680 0.380 0.232 0.164 0.126 0.094

1.64 5.47 13.68 27.37 68.42 109.47

1.5

e

log  p c



0.08

V b , pc 0.08

1.

e

log 

6.50 21.65 54.14 108.27 270.68 433.08 b) Thomeer (air-brine system)

a) J-function 300

.000 y = 0.826x-0.440 R² = 0.973

   i   s   p   n    i   c    P

.100 1.00

sample 4 -1.5 1

250

Lab-data sample 1

200

Lab-data sample 4

150 100

10.00

100.00 50

J-function S  w  S  w , irr  

0 . 826

 J 

 0 . 44

0 0.00

0.50 Sw

5  p c



1.00

Variable

Sample 1

Sample 2

 Pc

V b,Pc

V b,Pc

5 10 15 20 25 25 30 40 50 70 100 150 200 250 300

1.026 0.538 0.430 0.380 0.351 0.351 0.331 0.306 0.290 0.271 0.254 0.239 0.230 0.224 0.220

0.684 0.359 0.286 0.253 0.234 0.234 0.221 0.204 0.193 0.180 0.169 0.159 0.154 0.150 0.147

Archie parameter  Part 1: Formation factor (F) vs. Porosity (phi) Scal analyses data For regression with two parameters ( a  and m ) the first table (SCAL data) is used and pl For regression with one parameters ( m ) the second table (logarithms of data) is used a porosity 0.10 0.15 0.17 0.08 0.14 0.13

F 89.3 44.0 33.4 133.4 43.3 58.2

log por -1.000 -0.824 -0.770 -1.097 -0.854 -0.886

log F 1.951 1.643 1.524 2.125 1.636 1.765

a) 1000.0

2.00 1.28x -1.84

y= R² = 0.99

1.80

100.0 1.60

   )    F    (   g   o 1.40    l

   F

10.0 1.20 1.0 0.01

0.10 phi

1.00

1.00 -1.00

Part 2: Resistivity index (IR) vs.water sat

otted in plot a) d plotted in plot b)

Plug 1 Scal analyses data phi = 0.17 Sw 1 0.8 0.6 0.4 0.35 0.3 0.28

I=Rt/Ro 1.000 1.612 2.956 8.056 10.150 12.890 16.200

b) 1000.0

y = -1.958x R² = 0.985 100.0    R    I

10.0

-0.90

-0.80

-0.70

-0.60

-0.50

1.0 0.1

log (phi)

Result: For Log Analysis is a =  m =  n = 

uration (Sw)

y = 1.00x-2.19 R² = 1.00

1 Sw

 

used: 1.00 1.96 2.19

phi 0.02 0.1 1

F 2121.20806 90.782053 1