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An Investigation into the Prevention of Vertical Capillary Transport of Salt from Brine Contamination
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An Investigation into the Prevention of Vertical Capillary Transport of Salt from
Brine Contamination
Carla Landrum1, J. Berton Fisher1, Eleanor Jennings2, Shoeb Munshi2, Kerry Sublette2, Bryan Tapp1 and Dan Weber1
1Department of Geoscience; 2 Department of Chemical Engineering
Center for Applied BiogeosciencesUniversity of Tulsa
Introduction• Brine:
– Produced water– Byproduct of oil production – High levels of salt
• Historic disposal occurred on surface– Prior to environmental regulations – Multiple, deliberate exposures at location
• Historic brine scar resulted
Photo Credited to the USGS
• Traditional method of remediation– Addition of amendments (organic matter
and/or gypsum) to improve permeability– Irrigation to mobilize salt
• Problem:– Does not remove salt in deep soil layers– Salt can migrate vertically via capillary
movement– Recontamination of surface soils
TOP SOIL(ROOT ZONE)
UNSATURATED ZONE
(VADOSE ZONE)
PERCHED SATURATED ZONE
TOP SOIL(ROOT ZONE)
UNSATURATED ZONE
(VADOSE ZONE)
PERCHED SATURATED ZONE
Historic wells
LEGEND
PedestalPedestal A
Pedestal CPedestal C
Pedestal BPedestal B
Photo credited to USGSPhoto credited to USGS
Observations
• Brine scar floor– Loss of vegetation– Erosion
• Pedestals– Significant plant life
Photo credited to the USGS
Question?
What allows for the growth of vegetation on top of the pedestals with significant brine contamination at the base of the pedestal?
Hypothesis
Common soil texture within pedestals that prevents vertical migration of salt upwards into plant root zone
Goals
• Define contaminated and uncontaminated zones within each soil pedestal
• Identify interval separating the two zones
Materials and Methods• Soil cores taken
– Approx. 12.5 cm intervals for total depth of pedestal (average of 134 cm)
• Major Soil Analytics– Soil Texture– Na+ and SAR
• SAR= [Na+]/{([Ca+2]+[Mg+2])/2}1/2
– Electrical Conductivity (ECs)– Boron (Weber, et al. 2005)
Photo is not to scalePhoto credited to the USGS
PedestalA1 10 100 1000 10000
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
0% 20% 40% 60% 80% 100%1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Incr
easi
ng D
epth
Fro
m P
edes
tal S
urfa
ce
0 cm
147 cm
% Sand % Silt % Clay
Soil Texture
(μmhos
Boron (ppm) x 5000Na (ppm)Ec /cm)
1 100 10000 1000000
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
0% 20% 40% 60% 80% 100%
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Pedestal BIn
crea
sing
Dep
th F
rom
Ped
esta
l Sur
face
0 cm
157 cm
Increments are as Indicated
% Sand % Silt % Clay
Soil Texture(μmhos
Boron (ppm) x 5000Na (ppm)Ec /cm)
1 10 100 1000 10000
1
2
3
4
5
6
7
8
9
10
11
12
0% 20% 40% 60% 80% 100%1
2
3
4
5
6
7
8
9
10
11
12
Incr
easi
ng D
epth
Fro
m P
edes
tal S
urfa
ce
100 cm
Pedestal C
0 cm
% Sand % Silt % Clay
Soil Texture(μmhos
Boron (ppm) x 5000Na (ppm)Ec /cm)
1 10 100 1000
1
2
3
4
5
6
7
8
0% 20% 40% 60% 80% 100%1
2
3
4
5
6
7
8
Incr
easi
ng D
epth
Fro
m P
edes
tal S
urfa
ce
77 cm
0 cm
ControlIncrements are as Indicated
% Sand % Silt % Clay
Soil Texture(μmhos
Boron (ppm) x 5000Na (ppm)Ec /cm)
Pedestal ECs/% Sand
ECs/% Clay
SAR/% Sand
SAR/% Clay
A -0.84 0.42 -0.81 0.87
B -0.87 0.87 -0.86 0.92
C -0.86 0.89 -0.94 0.97
Correlation coefficients in red are statistically significant at p<0.05
Correlation of ECs and SAR with Soil Texture at Skiatook A
Study Expanded
• Historic brine scars in Tallgrass Prairie Preserve in northern Osage County– S1 and S3– Clearly visible in aerial
photographs from 1937
– Sampled pedestals and erosion bluffs
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
Depth (m)
0
10
20
30
40
50
60
70%
Cla
y
Clay Skia Clay S1 Clay S3
Clay Content Variation with Depth
0 10 20 30 40 50 60 70
% Clay
0
5
10
15
20
25
30
35
40EC
(mm
hos/
cm)
EC-Skia EC S1 EC-S3
ECs Variation with % Clay
0 10 20 30 40 50 60 70 80
% Sand
0
5
10
15
20
25
30
35
40EC
(mm
hos/
cm)
EC-Skia EC S1 EC-S3
EC Variation with % Sand
0 10 20 30 40 50 60 70
% Clay
0
5
10
15
20
25
30
35
40EC
(mm
hos/
cm)
EC-Skia EC S1 EC-S3
ECs Relative to Plant Growth
Negligible effects
Sensitive plants affected
Many plants
affected
Only salt tolerant plants
Only very salt
tolerant plants survive
SAR Variation with % Clay
0 10 20 30 40 50 60 70
% Clay
0
20
40
60
80
100
120
140
SAR
SAR-Skia SAR-S1 SAR-S3
0 10 20 30 40 50 60 70 80
% Sand
0
20
40
60
80
100
120
140SA
R
SAR-Skia SAR-S1 SAR-S3
SAR Variation with % Sand
SAR and Sodicity
0 10 20 30 40 50 60 70
% Clay
0
20
40
60
80
100
120
140
SAR
SAR-Skia SAR-S1 SAR-S3
Sodic
Conclusions
• Relationship between capillary movement of salt and soil texture is somewhat site specific
• These results suggest that significant vertical movement of salt in the soil column is prevented when % Sand > 60% and % Clay is < 10-15%
TOP SOIL
UNSATURATED ZONE
(ROOT ZONE)
VA
DO
SE
ZO
NE
Na+ Na+ Na+ Na+Na+ Na+
Capillary Break
PERCHED SATURATED ZONE
Project Significance
We have identified a common soil texture that inhibits the vertical migration of salt upwards into
a plant root zone.
This is a preliminary step towards a solution that prevents brine recontamination.
Acknowledgements
• Integrated Petroleum Environmental Consortium (IPEC)
• The University of Tulsa – Center for Applied Biogeosciences
• United States Geological Society (USGS)