remediation in fractured by...• varying slurp tube depth affect phc recovery • triton x-100 was...
TRANSCRIPT
Salah SharifParsons
Case Study: Remediation of Crude Oil in Fractured Shale using Multi‐Phase Extraction (MPE) Enhanced by Surfactant
www.vertexenvironmental.ca
SMART RemediationToronto, ON
January 28, 2016
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CASE STUDY: REMEDIATION OF CRUDE OIL IN FRACTURED SHALE USING MULTI-PHASE EXTRACTION (MPE) ENHANCED
BY SURFACTANT INJECTIONS
January 28, 2016Presented by:Salah Sharif, Ph.D., P.Geo.
Background
Conceptual Site Model
2013 Pilot Remediation Study
2015 Pilot Testing
Results
Conclusions
Next Steps
Background
Free Product discovered in 2002
Excavation of PHC impacted soil/rock in 2002 and 2009 up to 5 mbgs
Plastic sheeting placed along excavation walls on N, E, and W
PHC impacts remaining in fractured shale bedrock
2004 Risk Assessment (RA): No unacceptable risks to
human health or ecology, except excavation workers
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Target Area for MPE Pilot Study
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Background
Risk Management Plan (RMP) since 2004
More than 40 multi-level monitoring wells (MLMW) at different depths
Each MLMW comprised individual wells screened in A1 to A5 zones
Monthly product removal from wells
Semi-annual monitoring and sampling of groundwater
Confirm delineation is maintained and monitor for potential migration of PHC impacts
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Background
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Extent of Free Product (2014)
Extent of PHC F2 Plume (2014) Exceeding MOECC Criteria
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Conceptual Site Model
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Bedrock matrix is not impacted
Free Product in fractures in A2 zone
Generally PHC fractions F2-F4
PHC impacts delineated
All data indicated the dissolved plume is stable
No evidence that the free product is migrating horizontally/vertically
PHC F1 PHC F2 PHC F3
PHC F3 + PHC F4
A5
2013 Pilot Remediation Study
Objectives Estimate hydraulic properties of the bedrock including the radius of
influence (ROI) for groundwater extraction
Evaluate the ROI for vapour extraction in the overburden
Evaluate enhancement of free product recovery by injecting surfactants
Estimate design parameters for pilot-scale MPE
Evaluate NA parameters in groundwater to determine if Site conditions are favourable for biodegradation of PHC impact
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2013 Pilot Remediation Study
72-hour Pumping Test Draw-down response was similar to a leaky confined system
No drawdown in A2/A3 zones within 1m from pumping well in A4 zone for 6 hours after pumping started, after which drawdown in A2/A3 observed and continued to increase
Initial drawdown in pumping well (A4) was sharp and with continued pumping, drawdown flattened and stabilized indicating vertical leaking from the upper A2/A3 zones
Hydraulic conductivity values: A1: 5.7 x 10-5 m/s
A2: 7.5 x 10-6 m/s
A3: 3.5 x 10-6 m/s
A4: 2.5 x 10-6 m/s
For A2 zone Groundwater ROI of 15.2 m was calculated
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2013 Pilot Remediation Study
Vapor Extraction Test An ROI of 4.5 m was estimated
An air extraction rate 25 cfm
Surfactant Injection TestTriton X-100 solution (0.25%) with a fluorescent dye injected in BH36 Triton X-100 (Polyethylene glycol octylphenyl ether) - Non-ionic Surfactant
Two weeks later, the surfactant and dye were encountered mostly in the A2 zone up to 17 m N, 60 m S, and <20 m E and W from the injection well
Free product thickness increased in the injection well BH36 (from sheen to 435 mm)
Natural Attenuation (NA) Anaerobic biodegradation is evident in the PHC impacted A2 zone
Manganese/iron/sulfate reduction are likely NA processes
Due to the presence of free product and stable area of impact NA alone is not considered a significant attenuation process
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2013 Pilot Remediation Study
Recommendations Based on the results of the 2013 Pilot Remediation Study conditions are
considered favourable for the application of MPE to remediate PHC impacts, specifically free product and aqueous PHC phases
Surfactant is expected to enhance the performance of a MPE system, specifically the recovery of free product and dissolved PHC phases
Proceed to a pilot-scale surfactant enhanced MPE pilot testing
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Pilot Testing-2015
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Before Pilot Test Potable WaterInjection/Tracer testing To check hydraulic connection between
selected injection and extraction wells
To check capacity of injection wells to deliver surfactants
Injected 2000 L of potable water with fluorescent dye in each injection well (BH38 and BH24) at 20-40 psi and 15-20 L/min
Monitored extraction well (BH36) and surrounding observation wells for dye and groundwater levels including mounding, if any
Injection Well-2
Injection Well-1
Extraction Well
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Pilot Testing-2015
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Results of Potable Water Injection and Tracer tests Injection in BH24-A2 (distant well -15 m from extraction well BH36)
No dye detected in extraction well BH36
Poor connectivity between the injection well BH24(A2) and the selected MPE well BH36
Potable water with dye did not break-through to BH36
Injection in BH38-A2 (nearby well - 5 m from extraction well BH36) Dye detected in extraction well BH36 after 1 hr of injection
Injection capacity of both wells are sufficient to proceed with MPE test
Hydraulic control would be required for distant well BH24(A2) by creating a gradient towards the extraction well BH36
Pilot Testing-2015
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Combined Surfactant Injectionand MPE Week 1- extraction using mobile MPE
system from BH36 to collect baseline data
Week 2- Injection of 3000 L of 0.25% Surfactant (Triton X-100) with green dye in BH24A2 (distant)
Week 3- Injection of 4000 L of 0.25% Triton X-100 with pink dye into BH38A2 (nearby)
Week 4- Continued extraction with varying slurp tube depths Surfactant injected at a wellhead pressure
of <2-5 psi and a flow rate of 16-25 L/min
Water Extraction rate was 2 L/min
Daily monitoring and sampling (groundwater/vapors)
Injection Well- Week 2
Injection Well- Week 3
Extraction Well
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Pilot Testing-2015
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Diagram of the Mobile MPE Trailer
Pilot Testing-2015
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Extraction WellNearby Injection Well
Containment for Diesel AST & Generator
Carbon Filter TrailerMPE Trailer
Baker TankGenerator
Study Area Fenced
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Pilot Testing-2015
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Oil-Water Separator
Isolation Tank
Inside View of MPE Trailer
Results of Pilot Testing 2015
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Pilot and Post-Injection (4-week) Concentrations of PHC F3-F4 in BH-36
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Results of Pilot Testing 2015
Pilot and Post-Injection Concentrations of PHC F2-F4 in BH-36
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WEEK 1 WEEK 2 WEEK 3 WEEK 4 Post InjectionLOCATIONS BH 36 BH36 BH36 BH36 BH 36 BH 36 BH36 BH36 BH 36 BH36 BH36 BH36 BH36 BH36 BH36 BH36 BH36
Date Sampled 2015/05/26 2015/05/28 2015/06/01 2015/06/01 2015/06/04 2015/06/08 2015/06/09 2015/06/10 2015/06/11 2015/06/12 2015/06/15 2015/06/16 2015/06/17 2015/06/18 2015/06/19 2015/07/23 2015/10/30
Parameters
PHC F1 150 97 190 2200 31 40 7800 920 930 790 860 <25 <25 <25 <25 230 240
PHC F2 6000 2400 10 000 29 000 310 620 170 000 8400 23 000 18 000 1100 60 000 190 160 270 2800 <100
PHC F3 27 000 13000 51 000 130 000 3800 5100 540 000 47 000 120 000 74 000 4600 200 000 870 330 1400 1400 <100PHC F4 3300 2000 5400 18 000 1400 790 54 000 5200 15 000 6500 690 21 000 180 <100 210 140 <100
1 Month after Injection
4 Months after Injection
MPE & Surfactant Injection in Distant
Well BH24A2
MPE & Surfactant Injection in Nearby
Well BH38A2
Baseline: MPE and NO Surfactant Injection
MPE & Varying Slurp Tube Depth; No
Surfactant Injection
Results of Pilot Testing 2015
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DATE (yyyy/mm/dd)
2013/01/28
2013/02/20
2013/03/18
2013/04/12
2013/05/06
2013/06/14
2013/07/10
2013/08/09
2013/09/13
2013/10/09
2013/10/28
2013/11/06
2013/12/03
2014/01/27
2014/02/24
2014/03/27
2014/04/25
2014/05/20
2014/06/13
2014/07/16
2014/08/18
2014/09/25
2014/10/31
2014/11/24
2014/12/16
2015/01/26
2015/02/24
2015/03/23
2015/04/24
2015/05/25
2015/07/20
2015/08/27
2015/09/25
2015/10/26
2015/11/30
2015/12/17
FREE PRODUCT THICKNESSES(mm)
Sheen
Sheen
Sheen
Sheen
ND
Sheen
Sheen
10
Sheen
11
435
325
315
168
107
180
38
30
62
832
53
162
18
45
38
68
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33 3 3
Sheen
Sheen
ND
Sheen
ND
ND
Free Product in Extraction Well BH36
Surfactant Injection in 2013 increased free
product
During MPE & Surfactant Injection in June 2015
Recovery: 4 L of free product, 9 kg of dissolved PHC
Background free product
occurrences
After MPE & Surfactant Injection in 2015 (July-December)
No Free Product
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Conclusions
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• Pumping water without surfactant injection yielded little PHC recovery
• Maintaining hydraulic gradient ensures surfactant flow from distant injection well and increased ROI
• Surfactant increased dissolved PHC (F2-F4) recovery for short duration
• Surfactant mobilized LNAPL to extraction well
• Insignificant vapor-phase PHC recovery
• Varying slurp tube depth affect PHC recovery
• Triton X-100 was tested for positive bias of PHCs and was insignificant
• Approximately 13 kg of PHC removed in 3 weeks (4 L of free product, 9 kg of aqueous phase) from one extraction well
• MPE enhanced by surfactant injection is suitable for full-scale application
Next Step
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Full Scale Remediation Detailed design
Drilling
Treatability study for activated carbon consumption by surfactant and PHC mixed groundwater
During/process/post-remediation monitoring and sampling program
Expectation 2016-2019
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Thank You!
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Questions…
ACKNOWLEDGEMENTS
PARSONSJohn Halstead, M.Sc., P.Geo.Tom Li, P.Eng., M.A.Sc., M.B.A.
VERTEXBruce Tunnicliffe, M.A.Sc., P.Eng.Nathan Lichti, B.A.Sc., P.Eng.