CO2 Storage in Saline Aquifers

1
CO2 Storage in Saline Aquifers

• Mac Burton
• Representing Dr. Steven L. Bryant
• And
• Geological CO2 Storage Research Program

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Stabilizing Greenhouse Gas Emissions is a
World-Scale Task
INDUSTRY 29
Current annual emission as carbon 7 GT
2050 annual emission (Business As Usual Scenario) 14 GT
Emission cuts/CO2 removal needed for stabilization 7 GT
TRANSPORT 33
ELECTRICITY 38
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Meaningful Mitigation of GHG Emissions will
Require Geologic Sequestration (plus several
other technologies simultaneously)
Option Option Volume
Replace coal-fired electricity generation By gas-fired 1400 GW
Replace coal-fired electricity generation By wind 70 today
Replace coal-fired electricity generation By solar 1000 today
Replace coal-fired electricity generation By nuclear 700 1GW plants (2 today)
Geological storage Geological storage 3500 Sleipner projects
Hydrogen for transport Hydrogen for transport 1 billion cars
Double fuel economy of motor fleet Double fuel economy of motor fleet 2 billion cars _at_ 60 mpg
Biomass fuel from plants Biomass fuel from plants Area size of US agriculture
Each option would remove 1 Gt carbon/year
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Meaningful Geologic Sequestration will Require a
New Industry Comparable in Size to Current Oil
Gas Industry
Conversions between CO2 fluxes Conversions between CO2 fluxes Conversions between CO2 fluxes
1 wedge or Gt Introduced by Pacala and Socolow (2004)
109 Metric tons carbon/y
3.7?109 Metric tons CO2/y
190 BCFD CO2 Billion (109) standard cubic feet per day
105 MMBD CO2 Million barrels per day at typical deep aquifer conditions
Global gas production in 2006 277 BCFD
Global oil production in 2006 81.7 MMBD
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General Overview of Geologic Storage in Deep
Saline Aquifer

• Storage Mechanisms and General Plume Prediction
• Dissolution and Capillary Trapping
• Structural Trapping and Mineral
• Time to Reach Seal and Lateral Extent
• Injection Strategies
• Well Design
• Reservoir Characterization
• Leakage from Natural and Man-Made Features
• Leaking Faults
• Leaking Top Seal
• Leaking Wells

Standard Evaluation Techniques
Standard Evaluation Techniques
Requires New Evaluation Techniques and Science
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Why is Our Work in the Subsurface Important?

• Leakage of CO2 can pose a risk to
• Underground Assets
• Health Safety Environment
• Atmosphere (Emission Credits)

Wells and faults are primary potential leakage
pathways
Two Examples of Importance of Our Work
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Example 1 Active Well Leak and Abandon
Hundreds of Wells are Abandon in the Gulf of
Mexico each Year Wells in the Gulf are Few in
Number Compared to On-shore
5 to 30 of Active Wells per Field in Gulf of
Mexico have Leaks that Run to the Surface
Nicot et al, 2006
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Example 2 Injection Design
Pressure profile in aquifer
DEPTH
Pressure profile in well
PRESSURE
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Surface Dissolution Implementation Costs and
Technical Challenges

• Mac Burton
• Steven Bryant

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Key Findings

• Surface dissolution technology increases the
  available target aquifer space. Where?
• Shallower aquifers
• Aquifers with poor seal quality
• Operational and capital costs for surface
  dissolution are larger but comparable in
  magnitude to those for standard approach.
• Surface dissolution may be attractive where the
  costs of insuring against buoyancy-driven CO2
  leakage exceed these additional costs.
• Adds reasonable technology or options to our
  arsenal.

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Motivations for Alternate CO2 Storage Strategies
in Saline Aquifers

• Cheap Solution
• Simple Solution
• Safe Solution
• We choose to look at a strategy that will
• Lower Risk Option
• Address Technical Subsurface Challenges
• Adds to Current Technology or Expanding our
  Options

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Standard Approach to Sequestration-Retrofitting
Coal-Fired Power Plant
STANDARD APPROACH
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Costs for Standard Approach toAquifer
Sequestration
Costs of Standard Approach in for Carbon Sequestration in Saline Aquifer Costs of Standard Approach in for Carbon Sequestration in Saline Aquifer Costs of Standard Approach in for Carbon Sequestration in Saline Aquifer
Process Operationala Capitalb
Capture 17 500k- 1,000k
Compress and Inject 10 500k- 1,000k
Monitoring Buoyancy 0.5 0
Buoyant CO2 Liability TBD 0
a of Total Power Plant Capacity b per MW of Power Plant Capacity TBD to be determined a of Total Power Plant Capacity b per MW of Power Plant Capacity TBD to be determined a of Total Power Plant Capacity b per MW of Power Plant Capacity TBD to be determined
Sources Dr. Rochelles presentation to Dr.
Bryant research review, and Remediation of
Leakage from CO2 Storage Reservoirs, IEA GHG
Programme
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Standard Approach to Saline AquiferTechnical
Challenges

• Buoyant Migration
• Monitoring for Hundreds of Years
• Interaction with Faults, Seals, and Existing
  Wells
• Liability for Storage Cost and Probability of
• Remediation
• Lost Emission Credit
• Damage to Subsurface Assets
• Injectivity
• Reaching Pressure Limit In Closed Aquifer
• Relative Permeability and Capillary Pressure

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Surface Dissolution Approach to
Sequestration-Retrofitting Coal-Fired Power Plant
SURFACE DISSOLUTION
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Modeling Surface Dissolution Overview

• Solubility of CO2 in Brine (Aquifer Surface)
• Amount of Brine Needed
• Operational and Capital Costs

Ultimate Aquifer Solubility of CO2 in 10,000ppm-120,000ppm NaCl Brine Ultimate Aquifer Solubility of CO2 in 10,000ppm-120,000ppm NaCl Brine
Moles 1.5-2.2 mole
Mass 3.7-5.4 mass
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Modeling Surface Dissolution Solubility in
Brine in the Aquifer
Increasing salinity
Solubility CO2 (mole )
Aquifer Depth (ft)
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Modeling Surface Dissolution Brine Rate
Comparable to Other Plant Usage
Flow rates required for Captured CO2 for Coal-Fired Power Plant Flow rates required for Captured CO2 for Coal-Fired Power Plant Flow rates required for Captured CO2 for Coal-Fired Power Plant
General 500MW
CO2 Emitted 8000 tonne/yr-MW 4 million tonne/yr
Brine needed for Surface Dissolution 2,000-8,000 bbl/d-MW 1-4 million bbl/d
Typical Cooling Water for Coal-Fired Plant Typical Cooling Water for Coal-Fired Plant Typical Cooling Water for Coal-Fired Plant
Water for Once- through Cooling 14,000 bbl/d-MW 7 million bbl/d
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Operational and Capital Costs for Surface
Dissolution

• Operational Costs
• CO2 Compression
• Polytropic Compression
• ?79.6
• 4 stages
• Brine compression
• Incompressible
• 80 efficient

• Capital Costs
• Injection and Extraction wells
• 750,000 per well
• 35,000bbl/d-well
• CO2 Compressors and Brine Pumps
• 900,000 per MW consumed for pumping
• Pressure Mixing Vessel
• 25,000 per MW of power plant

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Costs for Surface Dissolution Approach
Costs of Surface Dissolution for Carbon Sequestration in Saline Aquifer Costs of Surface Dissolution for Carbon Sequestration in Saline Aquifer Costs of Surface Dissolution for Carbon Sequestration in Saline Aquifer
Process Operationala Capitalb
Capture 17 500k-1,000k 400k-900k
Extract and Inject 10 6-9 500k-1,000k 400k-900k
Monitoring Buoyancy 0 0
Buoyant CO2 Liability 0 0
a of Total Power Plant Capacity b per MW of Power Plant Capacity TBD to be determined a of Total Power Plant Capacity b per MW of Power Plant Capacity TBD to be determined a of Total Power Plant Capacity b per MW of Power Plant Capacity TBD to be determined
Costs of Surface Dissolution for Carbon Sequestration in Saline Aquifer Costs of Surface Dissolution for Carbon Sequestration in Saline Aquifer Costs of Surface Dissolution for Carbon Sequestration in Saline Aquifer
Process Operationala Capitalb
Capture 31 232,000
Extract and Inject 9-16 273,000 - 427,000
Monitoring Buoyancy 0 0
Buoyant CO2 Liability 0 0
a of Total Power Plant Capacity b per MW of Power Plant Capacity TBD to be determined a of Total Power Plant Capacity b per MW of Power Plant Capacity TBD to be determined a of Total Power Plant Capacity b per MW of Power Plant Capacity TBD to be determined
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Surface Dissolution in Saline AquiferTechnical
Challenges

• Surface Challenges
• Strong Temperature Dependence (Shallow is Better)
• Strong Salinity Dependence (Shallow is Better)
• Well Costs Influential (Shallow is Better)
• Dissolving CO2 in short time (less than few
  minutes)
• Carbonic acid might cause corrosion
• Subsurface Challenges
• Large Areal Target and Large Injection Volume
• Can we get the brine in and out?
• What if the CO2 -dense brine shows up at the
  extraction wells?

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Cost Comparison of Approaches
Comparison of Costs for Surface Dissolution vs. Standard Approach Comparison of Costs for Surface Dissolution vs. Standard Approach Comparison of Costs for Surface Dissolution vs. Standard Approach
Standard Surface Dissolution
Operating Costs 39-40a 41-46a
Capital Costs 300,000b 500,000 - 660,000b
Liability of Buoyancy Driven Leakage TBD 0
a of Total Power Plant Capacity b per MW of Power Plant Capacity TBD to be determined a of Total Power Plant Capacity b per MW of Power Plant Capacity TBD to be determined a of Total Power Plant Capacity b per MW of Power Plant Capacity TBD to be determined
Comparison of Costs for Surface Dissolution vs. Standard Approach Comparison of Costs for Surface Dissolution vs. Standard Approach Comparison of Costs for Surface Dissolution vs. Standard Approach
Standard Surface Dissolution
Operating Costs 28a 33-36a
Capital Costs 500k- 1,000kb 850k-1,800kb
Liability of Buoyancy Driven Leakage TBD 0
a of Total Power Plant Capacity b per MW of Power Plant Capacity TBD to be determined a of Total Power Plant Capacity b per MW of Power Plant Capacity TBD to be determined a of Total Power Plant Capacity b per MW of Power Plant Capacity TBD to be determined
5-8 More OPEX
Double CAPEX
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Cost Comparison of Approaches
Comparison of Costs for Surface Dissolution vs. Standard Approach Comparison of Costs for Surface Dissolution vs. Standard Approach Comparison of Costs for Surface Dissolution vs. Standard Approach
Standard Surface Dissolution
Operating Costs 28/tonne 33-36/tonne
Capital Costs 20- 40/tonne 34-72/tonne
Liability of Buoyancy Driven Leakage TBD 0
Totals 50-70/tonne 70-105/tonne
20-35 added / tonne
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ConclusionMotivation Evaluation
?

• Cheap Solution
• Simple Solution
• Safe Solution

• Pros
• Safety Sells
• No Buoyant Migration
• Interaction with Seal, Faults, Wells
• Increases Aquifer Availability

• Cons
• Added Costs
• Additional Fluid Handling
• Added Facilities (Compressors, Wells, etc.)
• Requires More Aquifer Space
• Technical Challenges (Carbonic Acid, Predicting
  Temperature, Predicting Reservoir, etc.)