Upload
micheal2
View
17
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Activities Handout
Citation preview
Core Analysis – Reducing Uncertainty
Activities
www.senergyworld.com/training
Activity 1
Porosity and Grain Density
Problem
Porosity and grain density measurements – SE Asian lab
Porosity measurements did not match logs
Test lab in UK repeated measurementsUsing SE Asian lab procedures
Own procedures
Grain volumeBoth labs use twin cell helium porosimeter (grain volume)
SE Asian lab used caliper bulk volume
UK lab used mercury immersion
Problem Data
Sample Sample Sample Dry Helium Caliper Immersion Caliper ImmersionNo. Length Diameter Weight Grain Bulk Bulk Grain Vb Vb
Volume Volume Volume Density Porosity Porosity(cm) (cm) (g) (cm3) (cm3) (cm3) (g/cm3) (%) (%)
1 4.558 3.791 112.720 40.458 50.8642 4.695 3.778 111.208 40.722 52.3693 4.712 3.773 99.014 38.354 50.9294 4.631 3.777 96.058 36.963 49.7425 4.668 3.782 95.640 37.076 50.4616 4.719 3.770 103.461 37.646 51.2857 4.567 3.786 97.667 36.895 49.924
Requirements
Calculate grain density (to 3D)
Calculate porosity based on caliper bulk volume
Calculate porosity based on Hg immersion bulk volume
Compare and comment on results
Length
Diameter
Activity 2
Klinkenberg Permeability Measurements
www.senergyworld.com/training
Activity - Klinkenberg
Data from Klinkenberg analysis
4 samples
Calculate Klinkenberg permeabilityKl
Calculate Ka at Pmean = 1 atm
Calculate Ka(1atm)/Kl
Plot Ka(1atm)/Kl versus Kl
Sample Depth Pmean Ka(m) (atm) (mD)
1 2900.5 1.006 1301.353 1261.647 1241.996 123
2 2901.8 1.083 34.61.427 33.31.721 32.52.075 31.9
3 2903.25 1.179 19.61.524 18.81.818 18.32.160 18
4 2927.57 1.001 2771.348 2711.642 2691.984 266
Sample 1 Chart
Sample 1
100
105
110
115
120
125
130
135
140
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Inverse Mean Pressure (atm-1)
Air
Per
mea
bili
ty (
mD
)
Sample 2 Chart
Sample 2
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Inverse Mean Pressure (atm-1)
Air
Per
mea
bili
ty (
mD
)
Sample 3 Chart
Sample 3
15
15.5
16
16.5
17
17.5
18
18.5
19
19.5
20
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Inverse Mean Pressure (atm-1)
Air
Per
mea
bili
ty (
mD
)
Sample 4 Chart
Sample 4
250
255
260
265
270
275
280
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Inverse Mean Pressure (atm-1)
Air
Per
mea
bili
ty (
mD
)
Activity 3
Stress Calculation for SCAL
www.senergyworld.com/training
Background
It is planned to carry out a SCAL program on plugs from an offshore sandstone reservoir
Tests are to be carried out at representative stress at a depth equivalent to the free water level in the sand – 9000 ft TVDSS (MSL)
Geomechanics data are available including:Average bulk density for principal overburden lithologies to calculate total vertical stress, v
Horizontal stress from mini-frac tests in reservoirh = 0.70*v H = 0.75v
Biot constant from rock mechanics tests = 0.95
Pore pressure from MDT4000 psi at 9000 ft TVDSS
Requirements
Calculate effective stress by two methodsNet effective overburden stress
Effective isostatic stress (Worthington method)
pvNEOB p '
phHv
iso p
3
'
Data
Vertical stress calculation
Calculate total vertical stress increment at base of each zone
H = zone vertical thickness (ft)
0.4335 convert g/cc to psi/ft
Calculate cumulative vv(cum) = v(1) + v(2) +v(3) + etc
Zone Description Top Base Average BaseDepth Depth Zonal Pore
Bulk PressureDensity
(ft TVDSS) (ft TVDSS) (g/cc) (psi)
1 Sea Water 0 300 1.00
2 Overburden 250 1500 1.70
3 Overburden 1500 3000 1.80
4 Overburden 3000 4500 1.90
5 Overburden 4500 6000 2.00
6 Overburden 6000 7500 2.20
7 Overburden 7500 8800 2.30
8 Reservoir 8800 9000 2.35 4000
Hzonev *4335.0)(
Activity 4
Porosity at Stress
www.senergyworld.com/training
Background/Objectives
Measurements of porosity as a function of confining stress on 1 sampleLab provided experimental data
expelled volume versus stressdata provided enables calculation of sleeve conformance pressure (SCP) and sleeve conformance volume
Calculatesleeve conformance pressure and excess volume
Correctexpelled volume data to determine pore volume reduction
Calculateporosity at each stress “station”
Estimate porosity and porosity compaction factorat effective overburden stress (from last example)at effective isostatic stress ((from last example)
Data
Porosity at stress
Vpstress = Vpamb-Vexp
Vbstress = Vpstress+Vgamb
assume constant grain volume
Check “uncorrected” porosity
Pore volume correction
Vpcorr = Vpexp-VSCP
Recalculate porosity based on corrected pore volume
Porosity compaction factor
Ambient PorositySample ID 7ELength, cm 3.85Area, cm2 11.00Pore Vol, cm3 7.657Bulk Vol, cm3 41.56Grain Vol, cm3 33.903Porosity, frac 0.184
Measured Measured Uncorrected Uncorrected UncorrectedSleeve Volume Pore Bulk Porosity
Pressure Expelled Volume Volume(psi) (cc) (ml) (ml) (v/v)40 1.26 6.40 40.30 0.15970 1.44 6.22 40.12 0.155
100 1.60 6.06 39.96 0.152130 1.70 5.96 39.86 0.149160 1.74 5.92 39.82 0.149190 1.78 5.88 39.78 0.148220 1.80 5.86 39.76 0.147250 1.84 5.82 39.72 0.146280 1.86 5.80 39.70 0.146800 1.92 5.74 39.64 0.1451600 2.04 5.62 39.52 0.1422500 2.10 5.56 39.46 0.1415000 2.18 5.48 39.38 0.139
Stressed Porosity Datastress
stressstress Vb
Vp
amb
stressPCF
SCP Chart
Volume Expulsion Chart
0.00
0.50
1.00
1.50
2.00
2.50
0 100 200 300 400 500 600 700 800 900 1000
Pressure (psi)
Vo
lum
e E
xpel
led
(m
l)
Porosity comparison chart
Porosity versus Stress
0.13
0.14
0.15
0.16
0.17
0.18
0.19
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000
Effective Isostatic Stress (psi)
Po
rosi
ty (
v/v)
Corrected porosity chart
Porosity versus Stress
0.170
0.171
0.172
0.173
0.174
0.175
0.176
0.177
0.178
0.179
0.180
0.181
0.182
0.183
0.184
0.185
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000
Effective Isostatic Stress (psi)
Po
rosi
ty (
v/v
)
Activity 5
Stress Corrections
Problem
RCA data from well
SCAL data available to correct data for stress effects
Depth Plug Ambient Grain HorizontalNumber Porosity Density Air
Permeability(ft) (%) (g/cc) (mD)
8472.0 404 19.1 2.64 1598473.0 405 20.5 2.64 2728473.8 406 21.7 2.62 5368475.0 407 22.5 2.638476.0 408 19.4 2.63 2918477.0 409 19.3 2.638478.0 410 17.7 2.648479.0 411 19.4 2.63 1168480.0 412 18.4 2.638481.0 413 19.6 2.63 1728482.0 414 17.2 2.628482.9 415 19 2.63 48
SCAL Data at ambient and NCS
PlugHelium Air Porosity kg@SwiPorosity Permeability 3900 psi 3900 psi
(%) (mD) (%) (mD)1 4.7 1.17 0.232 7.7 1.2 6.1 0.355 9.3 4.85 8.1 3.36 13.6 21.7 12.3 17.39 19.7 18.0
10 20.0 302 17.9 247.312 20.8 4125 17.5 352314 24.2 1985 21.6 152317 12.8 0.88 11.1 0.2118 11.1 2.68 1.0519 16.6 14.020 21.4 19.5
Ambient Data Stress Data
Requirements
Determine relationship between amb and NCS
Force fit (through 0)Free fit
Determine permeability stress & saturation correction transform
between kg @ Swi at overburden and ka at ambient conditions
For cored interval, calculate average:ambient porositystress corrected porosity (free fit and forced fit)air permeabilitystress-corrected effective endpoint gas permeability
Crossplot porosity versus permeabilityambient datastress-corrected data (forced fit porosity)
Porosity Correction Free Fit
Porosity Correction Forced Fit
Permeability Correction
0.1
1
10
100
1000
10000
0.1 1 10 100 1000 10000
Kair at Ambient (mD)
Eff
ec
tiv
e E
nd
po
int
Ga
s P
erm
eab
ilit
y at
Str
ess
(m
D)
Porosity-Permeability Crossplot
POROPERM PLOT
0.001
0.01
0.1
1
10
100
1000
10000
0 5 10 15 20 25 30
Porosity (%)
Pe
rme
ab
ilit
y (
mD
)
Use Force Fit Porosity
Activity 6
Archie and Waxman Smits Parameters
m and m*
Background
Multiple salinity tests (Co-Cw) carried out on 6 samplesDetermine formation factor to SFW at NCP
Rw = 0.901 ohm-m at 20 CCw = 1/Rw = 1.11 S/m
Multiple salinity tests (at 20 C)200,000 ppm brine Cw = 20.20 S/m150,000 ppm brine Cw = 15.87 S/m100,000 ppm brine Cw = 11.90 S/m50,000 ppm brine Cw = 6.80 S/m
Determine Co for each brineCrossplot Co versus Cw (including SFW)
Results: samples # 1 and #2
Sample Brine Cw Co(ppm) (S/m) (S/m)
1 SFW 1.11 0.135200000 20.20 2.246150000 15.87 1.795100000 11.90 1.34450000 6.80 0.763
Sample 1
y = 0.1112x + 0.0134
R2 = 0.9998
0.0
0.5
1.0
1.5
2.0
2.5
0.0 5.0 10.0 15.0 20.0 25.0
Cw (S/m)
Co
(S/m
)
Sample Brine Cw Co(ppm) (S/m) (S/m)
2 SFW 1.11 0.141200000 20.20 2.351150000 15.87 1.875100000 11.90 1.40650000 6.80 0.797
Sample 2
y = 0.1164x + 0.0131
R2 = 0.9998
0.0
0.5
1.0
1.5
2.0
2.5
0.0 5.0 10.0 15.0 20.0 25.0
Cw (S/m)C
o (S
/m)
Results: samples # 3 and #4
Sample Brine Cw Co(ppm) (S/m) (S/m)
3 SFW 1.11 0.135200000 20.20 1.866150000 15.87 1.492100000 11.90 1.12750000 6.80 0.653
Sample 3
y = 0.0911x + 0.0368
R2 = 0.9999
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0.0 5.0 10.0 15.0 20.0 25.0
Cw (S/m)
Co
(S/m
)
Sample Brine Cw Co(ppm) (S/m) (S/m)
4 SFW 1.11 0.151200000 20.20 2.309150000 15.87 1.843100000 11.90 1.38250000 6.80 0.796
Sample 4
y = 0.1135x + 0.0273
R2 = 0.9999
0.0
0.5
1.0
1.5
2.0
2.5
0.0 5.0 10.0 15.0 20.0 25.0
Cw (S/m)
Co
(S/m
)
Results: samples # 5 and #6
Sample Brine Cw Co(ppm) (S/m) (S/m)
5 SFW 1.11 0.145200000 20.20 1.923150000 15.87 1.535100000 11.90 1.16250000 6.80 0.681
Sample 5
y = 0.0934x + 0.0456
R2 = 0.9999
0.0
0.5
1.0
1.5
2.0
2.5
0.0 5.0 10.0 15.0 20.0 25.0
Cw (S/m)
Co
(S/m
)
Sample Brine Cw Co(ppm) (S/m) (S/m)
6 SFW 1.11 0.120200000 20.20 1.938150000 15.87 1.546100000 11.90 1.17250000 6.80 0.676
Sample 6
y = 0.0955x + 0.0235
R2 = 0.9998
0.0
0.5
1.0
1.5
2.0
2.5
0.0 5.0 10.0 15.0 20.0 25.0
Cw (S/m)
Co
(S/m
)
Requirements
Summary table
Calculate Archie m for each sample
Calculate composite mAverage and regression of log F and log data pairs
Calculate F* and Qv for each sample
Calculate Archie m* for each sample
Calculate composite m*Average and regression of log F* and log data pairs
Sample Stressed SFW SFW B Formation Slope Intercept BQv Qv Intrinsic m m*Porosity Rw Ro Factor F*
(v/v) (ohm-m) (ohm-m) (meqml-1/Sm-1) F (1/F*) (BQv/F*) (meq/ml)1 0.301 0.901 7.41 1.968 8.22 0.1112 0.01342 0.310 0.901 7.09 1.968 7.87 0.1164 0.01313 0.237 0.901 7.41 1.968 8.22 0.0911 0.03684 0.286 0.901 6.62 1.968 7.35 0.1135 0.02735 0.286 0.901 6.90 1.968 7.65 0.0934 0.04566 0.288 0.901 8.33 1.968 9.25 0.0955 0.0235
m m*MeanComposite
Chart
1
10
1 10
Stressed Porosity (v/v)
Intr
insi
c F
orm
ati
on
Fac
tor
or
Fo
rma
tio
n F
acto
r (-
)
Calculation
Y on X regressionSlope = 1/F*
Intercept = BQv/F*
B = 1.968
Sample 5
y = 0.0934x + 0.0456
R2 = 0.9999
0.0
0.5
1.0
1.5
2.0
2.5
0.0 5.0 10.0 15.0 20.0 25.0
Cw (S/m)
Co
(S/m
)
BT T
R Tw
128 0 225 0 0004059
1 0 045 0 27
2
1 23. . .
( . . ).
Activity 7
Archie and Waxman Smits Parameters
n and n*
Background
Resistivity index tests carried out on 1 sample
Qv also determined:by wet chemistry tests (CEC Qv)
by multiple salinity tests (Co-Cw Qv)
Calculate:Archie saturation exponent
For each Sw point
By regression analysis (log I versus Log Sw)
Intrinsic saturation exponentFor each Sw point
By regression analysis (log I versus Log Sw)
For both CEC Qv and Co-Cw Qv
Data
Wet Chemistry Qv
Sample Grain Porosity Wet Co-Cw SFW SFW n* SFW Water Resistivity Intrinsic Archie IntrinsicDensity Chemistry Qv Rw Temp Qv B Saturation Index Resistivity Saturation Saturation
CEC Sw I Index Exponent Exponent
(g/cc) (frac) (meq/100g) (meq/ml) (ohm.m) (Deg C) (meq/ml) (meqml-1/Sm-1) (frac) (frac) I* n n*1 2.65 0.301 2.86 0.061 0.901 20.0 1.967 1.000 1.00
0.820 1.520.370 6.670.322 8.650.256 13.320.235 15.830.211 18.950.193 24.09
n n*Composite
Co-Cw Qv
Sample Grain Porosity Wet Co-Cw SFW SFW n* SFW Water Resistivity Intrinsic Archie IntrinsicDensity Chemistry Qv Rw Temp Qv B Saturation Index Resistivity Saturation Saturation
CEC Sw I Index Exponent Exponent
(g/cc) (frac) (meq/100g) (meq/ml) (ohm.m) (Deg C) (meq/ml) (meqml-1/Sm-1) (frac) (frac) I* n n*1 2.65 0.301 2.86 0.061 0.901 20.0 1.967 1.000 1.00
0.820 1.520.370 6.670.322 8.650.256 13.320.235 15.830.211 18.950.193 24.09
n n*Composite
Charts
1
10
100
0.1 1
Water Saturation (v/v)
Intr
insi
c R
esis
tiv
ity
Ind
ex o
r R
esi
stiv
ity
Ind
ex(-
)
Calculations
Saturation exponent, nRegression analysis of log(I) and log(Sw)
Qv (from CEC)
Intrinsic saturation exponent, n*Calculate I*
Regression analysis of log(I) and log(Sw)
res
resgres
CECQv
100
1
)log(
)log(
Sw
In
)1(
)1(
*w
w
w
BQvR
SBQvR
II
)log(
*)log(*
Sw
In
Activity 8
Saturation Exponent from Dean Stark
Dean-Stark and Rt
Well drilled with OBMNo SCAL dataDean-Stark available
in oil leg above transition zonecorrected for stress
Pickett plot in water legm = 1.81Rw = 0.0413 ohm-m at 79 C
Dean-Stark matched to logsRt versus Dean-Stark Sw
Calculate saturation exponent ‘n’
amb
ambPCFSwSw
1
1
*
Sw and Rt versus depth
9840
9845
9850
9855
9860
9865
9870
9875
0 5 10 15 20 25 30 35
RT (ohm-m)
De
pth
(ft
)
9840
9845
9850
9855
9860
9865
9870
9875
0.0 0.1 0.2 0.3 0.4 0.5
Dean-Stark Sw (v/v)
Dep
th (
ft)
Dean-Stark and Rt crossplot
Dean Stark Sw and RT
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50
Dean-Stark Sw (v/v)
RT
(o
hm
-m)
Dean-Stark Data
Stressed Corrected Log Estimated Estimated Resitivity Log RI Log Sw SaturationShifted Core Dean Stark Rt F Ro Index Exponent
Sample Depth Porosity Sw (1/m) I nNumber Feet (v/v) (v/v) (ohm-m) (ohm-m)1HDS 9843.6 0.155 0.207 22.1672VDS 9844.8 0.145 0.237 21.7193HDS 9845.5 0.168 0.209 21.7194HDS 9846.6 0.151 0.216 24.3185HDS 9847.5 0.179 0.167 24.0886VDS 9848.5 0.165 0.178 25.1447HDS 9849.6 0.163 0.183 26.019
10HDS 9852.3 0.163 0.177 28.45314HDS 9856.5 0.132 0.203 31.63121HDS 9863.5 0.149 0.258 17.30622HDS 9864.5 0.126 0.328 15.35523HDS 9865.5 0.169 0.220 17.33326HDS 9868.5 0.150 0.248 16.47527HDS 9869.5 0.159 0.219 17.19528HDS 9870.5 0.159 0.224 17.63129HDS 9871.5 0.152 0.215 19.573
Tasks
For each datapointcalculate formation factor, F
calculate Ro
calculate resistivity index, I, based on log Rt and calculated Ro
calculate saturation exponent, ‘n’
Calculate composite ‘n’Crossplot I versus Dean-Stark Sw
Saturation exponent plot
1
10
100
0.1 1
Stress-Corrected Dean-Stark Sw (v/v)
Re
sis
tiv
ity
Ind
ex
(R
t/R
o)
Log I versus log Sw
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
2.00
-1 -0.9 -0.8 -0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0
Log Sw
Lo
g I
Activity 9
Mercury Injection Capillary Pressure
Closure Correction
Background
High pressure MICP test on chip sampleInject mercury to fill pore volume (58000 psi)
Lab interpretationClosure correction (entry pressure, Pce)
Pore volume filled with mercury
Mercury saturation (fraction pore volume)
Sw versus Pc curve
Raw data providedCumulative volume of mercury versus injection pressure
Allows alternative interpretationPce
Sw versus Pc
Data
Pore volume
Vp = total injection volume – closure volume
Total injection volume = 0.6768 ml
Closure pressure = 11.1 psi
Closure volume = 0.0155 ml
Pore volume = 0.6613 ml
Sample Depth, feet: 7889.97Plug Kair, mD: 2.3 Entry Pressure 11.1 psia
Plug Porosity, fraction: 0.216 Closure Volume 0.0155 mlInjection Sample Porosity, fraction: 0.212 Pore Volume 0.6613 ml
Injection Sample Pore Volume, cm3: 0.661Injection Sample Bulk Volume, cm3: 3.115
LAB DATA RAW DATAInjection Mercury Equivalent Pore Normalized Comments CumulativePressure Saturation Water Throat Pore Injection
Saturation Radius, Size VolumeDistribution
(psia) (v/v) (v/v) (microns) Function (ml)0.5 0.000 1.000 221.392 0.000 Closure 0.00000.8 0.000 1.000 133.364 0.000 Closure 0.00651.1 0.000 1.000 94.482 0.000 Closure 0.01041.4 0.000 1.000 79.199 0.000 Closure 0.01171.5 0.000 1.000 71.061 0.000 Closure 0.01231.7 0.000 1.000 62.055 0.000 Closure 0.01302.0 0.000 1.000 55.257 0.000 Closure 0.01302.2 0.000 1.000 48.260 0.000 Closure 0.01362.5 0.000 1.000 42.891 0.000 Closure 0.01362.9 0.000 1.000 37.835 0.000 Closure 0.01363.3 0.000 1.000 33.209 0.000 Closure 0.01363.6 0.000 1.000 29.656 0.000 Closure 0.01364.0 0.000 1.000 26.995 0.000 Closure 0.01424.3 0.000 1.000 25.352 0.000 Closure 0.01424.6 0.000 1.000 23.620 0.000 Closure 0.01424.8 0.000 1.000 22.701 0.000 Closure 0.01425.1 0.000 1.000 21.350 0.000 Closure 0.01425.4 0.000 1.000 20.084 0.000 Closure 0.01425.6 0.000 1.000 19.194 0.000 Closure 0.01425.9 0.000 1.000 18.194 0.000 Closure 0.01426.1 0.000 1.000 17.588 0.000 Closure 0.01426.4 0.000 1.000 16.741 0.000 Closure 0.01426.8 0.000 1.000 15.949 0.000 Closure 0.01427.0 0.000 1.000 15.337 0.000 Closure 0.01427.4 0.000 1.000 14.669 0.000 Closure 0.01427.7 0.000 1.000 13.958 0.000 Closure 0.01427.9 0.000 1.000 13.599 0.000 Closure 0.01428.4 0.000 1.000 12.900 0.000 Closure 0.01428.8 0.000 1.000 12.257 0.000 Closure 0.01429.0 0.000 1.000 11.973 0.000 Closure 0.01499.5 0.000 1.000 11.291 0.000 Closure 0.0149
10.2 0.000 1.000 10.618 0.000 Closure 0.015510.3 0.000 1.000 10.467 0.000 Closure 0.015511.1 0.000 1.000 9.749 0.000 Entry Pressure 0.015511.7 0.002 0.998 9.250 0.045 0.016812.5 0.004 0.996 8.649 0.039 0.018113.3 0.004 0.996 8.132 0.033 0.018114.4 0.005 0.995 7.475 0.059 0.018815.1 0.008 0.992 7.124 0.073 0.020716.4 0.010 0.990 6.572 0.059 0.0220
Laboratory Interpretation
Vp
VhgSHg Hgwet SS 1
Lab Pc Curve
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00
Wetting Phase Saturation (v/v)
Inje
ctio
n P
ress
ure
(p
sia)
Lab
Closure (Lab)
Pce underestimated?
0
20
40
60
80
100
120
140
160
180
200
0.00 0.05 0.10 0.15 0.20 0.25 0.30
Volume Injected (ml)
Inje
ctio
n P
ress
ure
(p
sia)
Lab entry pressure 11.1psiShglab = 0 : Swetlab = 1
Requirements
Review “raw” dataPlot injected volume versus pressure
Linear scale ( 0 – 200 psi)
Logarithmic scale
Make alternative interpretationPce
closure volume
Correct and calculatemercury filled pore volume (ml)
mercury saturation
wetting phase saturation
Charts – Injected Volume
0
20
40
60
80
100
120
140
160
180
200
0.00 0.05 0.10 0.15 0.20 0.25 0.30
Volume Injected (ml)
Inje
ctio
n P
ress
ure
(p
sia)
Charts – Pc versus Swet
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00
Wetting Phase Saturation (v/v)
Inje
ctio
n P
ress
ure
(p
sia)
Activity 10
Capillary Pressure Comparison
Problem
Cap pressure data measured on 2 samplesair-brine (porous plate)
air-mercury (mercury injection)
Requirementsconvert both datasets to lab equivalent oil-brine
compare and comment on data
Data
Support Desk Help
To avoid tedious calculations
calculate every second point for air-mercury data (but
calculate last point)
Air-Brine Data Air-Mercury Data
2B Plug 2C Plug12.5 Air Permeability (mD) 5.2 Air Permeability (mD)19.8 Porosity (%) 19.7 Porosity (%)
Water Capillary Air CapillarySaturation Pressure Saturation Pressure
(%) (psig) (%) (psia)100.0 0 100.0 191.1 1 100.0 290.8 2 100.0 389.7 4 100.0 675.0 8 100.0 965.6 16 100.0 1259.5 32 99.2 1553.4 75 96.7 1850.4 200 94.4 21
91.0 2487.5 2784.7 3077.2 4069.5 6065.0 8061.8 10052.5 20049.2 30044.9 50039.8 75036.0 100032.5 125029.3 150026.7 175025.6 2000
Capillary Pressure Chart
Capillary Pressure
0
50
100
150
200
250
0 10 20 30 40 50 60 70 80 90 100
Wetting Phase Saturation (%)
Oil-
Bri
ne C
apill
ary
Pre
ssur
e (p
si)
Activity 13
Relative Permeability Endpoints
Waterflood Test
Test ProceduresMeasure plug Ka and Saturate in water (SFW)
Reduce to Swircentrifuge or porous plate at maximum Pc
Saturate in test oil (15 cp)
Measure endpoint oil permeability, Ko’ at Swirat 1000 psi NCS
Waterflood (SFW)flow until 99.9% water cut (fw = 0.995)
measure TOTAL volume oil produced – at Sro
Measure endpoint water permeability, Kw’ at Sro
Endpoints
Measure base parameterska = 150 mD, = 0.23
Saturate core in water (brine)
Desaturate to SwirCentrifuge or porous plate
Swir = 0.xx
Measure oil permeability Ko’ @ Swir – endpointKo’ = xx mD
Waterflood – collect oilSro = 0.xx
Swr = 1-0.xx = 0.xx
Measure water permeability Kw’ @Sro – endpointKw’ = xx mD
So = 1-Swir
Swirr
Oil = Sro
Sw = 1-Sro
Data Input
D
4
2DA
pA
LQk
1 atm = 14.7 psi
Sample DataConfining Pressure 1000 psiAir Permeability (Ka) 150 mD 1 atm 14.7 psiPorosity 0.23 v/vPore Volume 12.63 cm3Length (L) 4.79 cmDiameter 3.82 cmArea (A) 11.46 cm2 Relative PermeabilityOil Viscosity (mu) 15 cp Sw kro' krw'Water Viscosity (mu) 1 cp (v/v) (Ref Ko') (Ref Ko')
0.20 1.00 0Initial water volume 2.53 cm3 0.75 0 0.30Swir 0.20 v/v Sw kro' krw'
(v/v) (Ref Ka) (Ref Ka)Oil produced 6.94 cm3 0.20 0.53 0Final water volume 9.47 cm3 0.75 0 0.16Final water saturation 0.75 v/vResidual Oil, Sro 0.25 v/vRecovery Factor 68.8 %OIP
Endpoint Differential Vol, Time, Viscosity Q dP PermeabilityPressure(psi) (cm3) (sec) (cp) (cm3/sec) (atm) (mD)
Ko' Endpoint 23.05 20 1000 15 0.0200 1.568 80.0Kw' Endpoint 17.07 20 300 1 0.0667 1.161 24.0
Ko' Endpoint
Kw' Endpoint
Endpoints - Tasks
CalculateSwir (fraction)
Ko’ at Swir from Darcy’s Law
Sro (fraction) from oil recovery and material balance
Recovery factor (% OIP)
Kw’ at Sro from Darcy’s Law
Relative permeabilityEndpoint kro’ and krw’ based on Ko’ reference
Endpoint kro’ and krw’ based on Ka reference
PlotEndpoint relative permeabilities versus Sw
Relative permeability chart
Relative Permeability Chart
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
Water Saturation (v/v)
Re
lati
ve
Pe
rme
ab
ilit
y,
kr
Syndicate Exercise
SCAL Programme Design
Oil Reservoir - Background
Appraisal well – consolidated sandstone reservoir10000 ft (3300 m) TVDSS
Core drilled with OBM Air Permeability – 10 mD to 500 mDHelium Porosity – 15% to 25%Formation has trace to 10% clays (mainly illite/smectite)RCA completed - ~ 15 preserved samples available
only 3 off 1.5” plugs possible per sample
Water injection planned – facilities design is an issueNo gas cap, produce above Pb
Data Available
RFT data
Welltest kh
Good log suite – density, resistivity etc but local bad hole conditions
PVT properties
Routine core analysis data (total porosity, ka, no Dean-Stark)
Petrographic data
Objectives - Petrophysics
Oil Initially In Placedensity log requires calibration
resistivity logs require calibration (Archie and Waxman-Smits)
FWSalinity ~ 50000 ppm
Saturation-height model.Validate log Sw-height as concerns over bad hole conditions
Validate welltest kh
Objectives – Reservoir Engineering
Establish recovery factor
Waterflood design data
Validate welltest kh
Design SCAL Programme
What tests do you need to do?
How would you do these tests (which method)?
What do you need to consider ?Other data?
Core preparation ?
Core damage?
Test methods ?
Pragmatism
Must have data for FDP in 6 months