Geologic Storage of CO2
Next Generation Coal
Howard Herzog
MIT Laboratory for Energy and Environment
October 6, 2005
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IPCC Special Report
• Intergovernmental Panel on Climate Change
(IPCC)
• Working Group III
• Special Report on Carbon Dioxide Capture
and Storage
• Accepted September 26, 2005
• Summary for Policymakers on-line at
www.ipcc.ch
Howard Herzog / MIT Laboratory for Energy and the Environment
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IPCC Special Report
Overview
Storage of CO2 in deep, onshore or offshore, geological formations uses
many of the same technologies that have been developed by the oil and
gas industry and has been proven to be economically feasible under
specific conditions for oil and gas fields and saline formations, but not
yet for storage in unminable coal beds.
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Carbon dioxide can be stored in several geological
targets, usually as a supercritical phase
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Experience and Evolution from Oil &
Gas Operations
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Acid Gas Injection
Enhanced Oil Recovery (EOR)
Natural Gas Storage
CO2 Transport
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Acid Gas Injection
• First began: Acheson Field, 1989
• In 2001, nearly 6.5 Billion cubic
feet (360,000 tonnes) of acid gas
injected at > 30 locations.
• Between 50 thousand and 5
million scf per day. Compositions
vary but many over 90% CO2.
• Largest: Westcoast Energy injects
28 million scf per day (Sleipner:
50 million scf of CO2 per day)
Acid Gas Disposal sites in Alberta, Canada. Map
provided by Nickle’s New Technology Magazine,
September 13, 2002
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Enhanced Oil Recovery
• First began: Scurry County, Texas, 1972
• In 2000, 84 commercial or research-level CO2-EOR
projects operational worldwide (72 in US)
• Rangely Field (Colorado)
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Started CO2 injection in 1986
346 producers, 235 injectors
Injection rate of about 150 million scf/day (8300 t/d)
Estimated leak rate of <170 tons/yr out of 23 million tonnes
purchased (<0.001%/yr)
 Source: Applied Geochemistry, vol. 18, pp.1825-1838 (2003).
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Natural Gas Storage
• First began: 1915 in a partially
depleted gas field.
• Total storage 1955: 2.1 Tcf
• Total storage 1985: 8 Tcf
•
Volume of 8 Tcf will store one year of
all US power plant CO2 emissions
• Since 1980’s, storage capacity has
stabilized at around 8 Tcf while
capacity to deliver has increased
Natural Gas Storage by Type available at
http://www.fetc.doe.gov/scng/trans-dist/ngs/storage-ov.html
• Total US consumption 2000 > 22
Tcf
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CO2 Transport
• Extensive network of CO2 pipeline
stretching nearly 2000 miles, mostly
in the United States
• 49CFR195 addresses transport of
hazardous liquids and CO2
 CO2 pipelines classified as High Volatile
Low Hazard and Low Risk.
• Canyon Reef Carriers (CRC) pipeline, 1972
 Relatively few failures (with no injuries)
 Extends 140 miles from McCarney, Texas, to Kinder Morgan’s SACROC field
 Size: 16 inches in diameter with capacity to deliver up to 240 MMscf of CO2
per day
Howard Herzog / MIT Laboratory for Energy and the Environment
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IPCC Special Report
Overview
Storage of CO2 in deep, onshore or offshore, geological formations uses
many of the same technologies that have been developed by the oil and
gas industry and has been proven to be economically feasible under
specific conditions for oil and gas fields and saline formations, but not
yet for storage in unminable coal beds.
…
Three industrial-scale storage projects are in operation: the Sleipner
project in an offshore saline formation in Norway, the Weyburn EOR
project in Canada, and the In Salah project in a gas field in Algeria.
Others are planned.
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CO2 Injection Projects
Million Tonne per Year Scale
Project
Sleipner
Weyburn
In Salah
Snovit
Leader
Location
CO2 Source
North Sea
Gas
Statoil
Norway
Processing
Pan
Saskatchewan
Coal
Canadian
Canada
Gasification
BP
Algeria
Gas
Processing
Statoil
Barents Sea
Norway
Gas
Processing
Howard Herzog / MIT Laboratory for Energy and the Environment
CO2 Sink
Deep Brine
Formation
EOR
Depleted Gas
Reservoir
Deep Brine
Formation
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IPCC Special Report
Capacity
Available evidence suggests that worldwide, it is likely that there is a
technical potential of at least about 2,000 GtCO2 (545 GtC) of
storage capacity in geological formations.
There could be a much larger potential for geological storage in
saline formations, but the upper limit estimates are uncertain due to
lack of information and an agreed methodology. The capacity of oil
and gas reservoirs is better known. Technical storage capacity in coal
beds is much smaller and less well known.
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Site Selection
• Reservoir Characteristics
 Injectivity
 Accessible pore volume
 Containment
• Reachable from CO2 Source
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IPCC Special Report
Regulation
Some regulations for operations in the subsurface exist that may be
relevant or in some cases directly applicable to geological storage,
but few countries have specifically developed legal or regulatory
frameworks for long-term CO2 storage.
Existing laws and regulations regarding inter alia mining, oil and gas
operations, pollution control, waste disposal, drinking water,
treatment of high-pressure gases, and subsurface property rights may
be relevant to geological CO2 storage. Long-term liability issues
associated with the leakage of CO2 to the atmosphere and local
environmental impacts are generally unresolved. Some States take on
long-term responsibility in situations comparable to CO2 storage,
such as underground mining operations.
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Howard Herzog / MIT Laboratory for Energy and the Environment
Permitting - Current
• EPA Underground Injection Control (UIC) Program
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Created under the Safe Drinking Water Act (1974)
Almost all underground injections must be authorized by permit
Exemption for natural gas storage
States may receive primacy for permitting – some states currently
do allow injection into deep saline aquifers
• Five classes of UIC injection wells
 Relaxed standards for injection wells related to enhanced oil
recovery (CO2-EOR)
 No class specific to carbon sequestration
 Pilot projects have been permitted under the Class V experimental
well category
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Measurement, Monitoring, and
Verification
• Role of MMV
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Understand key features, effects, & processes
Injection management
Delineate and identify leakage risk and leakage
Provide early warnings of failure
Verify storage for accounting and crediting
• Currently, there are abundant viable tools and
methods, but MMV systems still need to be
developed
Howard Herzog / MIT Laboratory for Energy and the Environment
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IPCC Special Report
Leakage
Observations from engineered and natural analogues as well as
models suggest that the fraction retained in appropriately selected
and managed geological reservoirs is very likely to exceed 99% over
100 years, and is likely to exceed 99% over 1,000 years.
For well-selected, designed and managed geological storage sites, the
vast majority of the CO2 will gradually be immobilized by various
trapping mechanisms and, in that case, could be retained for up to
millions of years. Because of these mechanisms, storage could
become more secure over longer timeframes.
Howard Herzog / MIT Laboratory for Energy and the Environment
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Storage Mechanisms
• Physical trapping
 Impermeable cap rock
 Either geometric or hydrodynamic stability
• Residual phase trapping
 Capillary forces immobilized fluids
 Sensitive to pore geometry (<25% pore vol.)
• Solution/Mineral Trapping
 Slow kinetics
 High permanence
• Gas adsorption
 For organic minerals only (coals, oil shales)
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Leakage
• Some leakage is inevitable – question is whether
the leakage will have any impacts on HSE or
climate (there is active debate on value of
temporary storage)
• Pathways
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Well integrity (cement damage)
Fracturing
Faulting
Permeation and Spillover
• Leakage rate not a simple logistic function (i.e.,
x% per year)
Howard Herzog / MIT Laboratory for Energy and the Environment
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IPCC Special Report
Risks
With appropriate site selection informed by available subsurface
information, a monitoring program to detect problems, a regulatory
system, and the appropriate use of remediation methods to stop or
control CO2 releases if they arise, the local health, safety and
environment risks of geological storage would be comparable to
risks of current activities such as natural gas storage, EOR, and deep
underground disposal of acid gas.
… Impacts of elevated CO2 concentrations in the shallow subsurface
could include lethal effects on plants and subsoil animals, and
contamination of groundwater. High fluxes in conjunction with stable
atmospheric conditions could lead to local high CO2 concentrations
in the air that could harm animals or people. Pressure build-up
caused by CO2 injection could trigger small seismic events.
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Howard Herzog / MIT Laboratory for Energy and the Environment
Types of Risk
• Operational Risks
 Managed today
• Climate Risks
 Liability that can be handled
• In Situ Risks
 Formation leaks to the surface
 Migration within formation
 Seismic events
Howard Herzog / MIT Laboratory for Energy and the Environment
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IPCC Special Report
Accounting
The current IPCC Guidelines do not include methods specific to
estimating emissions associated with CCS.
The general guidance provided by the IPCC can be applied to CCS. A
few countries currently do so, in combination with their national
methods for estimating emissions. The IPCC guidelines themselves
do not yet provide specific methods for estimating emissions
associated with CCS. These are expected to be provided in the 2006
IPCC Guidelines for National Greenhouse Gas Inventories…
Howard Herzog / MIT Laboratory for Energy and the Environment
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Geological Storage
General Conclusions
• Practical issues
 CO2 transport, injection and storage has been occurring since the early 1970’s.
Tens of millions of tons of CO2 are injected annually.
 Further scale up would be required to play significant role in US power sector
CO2 abatement. All key technologies and practices are in current commercial
operation. No “breakthrough” technological innovations appear necessary for
this scale-up.
 Volume of the total annual US power sector CO2 emissions are in the same order
of magnitude volume of other key US gas and fluids currently injected and
stored underground (e.g., natural gas, wastewater in Florida, oilfield brines)
• Environmental issues
 Based on our study of analogues, short term (three-decade) and local
environmental risks are well understood and can be managed by current industry
best practices.
 Long term (beyond three decade) risks are by definition uncertain but no
evidence to date suggests significant leakage.
 Best near term course of action is to conduct pilot projects to gather information
that will allow us to address the issue of long term risks and uncertainties.
Howard Herzog / MIT Laboratory for Energy and the Environment
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Contact Information
Howard Herzog
MIT Laboratory for Energy and the
Environment (LFEE)
Room E40-447
Phone: 617-253-0688
E-mail: [email protected]
Web Site: sequestration.mit.edu
Howard Herzog / MIT Laboratory for Energy and the Environment
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