RECS 2015

Fundamentals of CO2 Storage

Travis L. McLing Idaho National Laboratory\Center For Advanced Energy Studies.

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CCS Operation Chain

Capture Underground

Injection & Storage Pipeline

Transport Compression

Operational Stages of CO2 Storage

Site characterization is a continuous, iterative process during all operational stages of a CO2 storage project

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Key Elements of a Geological Storage

Safety and Security Strategy

Regulatory Oversight

Remediation

Monitoring

Safe Operations

Storage Engineering

Site Characterization

and Selection

Fundamental Storage

and Leakage Mechanisms

Financial

Responsibility “… the fraction retained is likely to exceed 99% over 1,000 years.”

“ 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…”

IPCC, 2005

“… risks similar to existing activities such as natural gas storage and EOR.”

Key Elements of a Geological Storage

Safety and Security Strategy

Regulatory Oversight

Remediation

Monitoring

Safe Operations

Storage Engineering

Site Characterization

and Selection

Fundamental Storage

and Leakage Mechanisms

Financial

Responsibility “… the fraction retained is likely to exceed 99% over 1,000 years.”

“ 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…”

IPCC, 2005

“… risks similar to existing activities such as natural gas storage and EOR.”

Key Elements Geological Storage: Safety, and Security Strategy

Basic Concept of Geologic Sequestration

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Basic Concept of Geological

Sequestration of CO2

•! Injected at depths of 1 km or deeper

into rocks with tiny pore spaces

•! Primary trapping –! Beneath seals of low permeability rocks

Image courtesy of ISGS and MGSC

Courtesy of John Bradshaw

What Types of Rocks are Suitable

for CO2 Storage?

•! Igneous rocks –! Rocks formed from cooling magma

–! Examples •! Granite

•! Basalt

•! Metamorphic Rocks –! Rocks that have been subjected to high

pressures and temperatures after they are formed

–! Examples •! Schist

•! Gneiss

•! Sedimentary rocks –! Rocks formed from compaction and

consolidation of rock fragments

–! Example •! Sandstone

•! Shale

–! Rocks formed from precipitation from solution –! Example

•! Limestone

Granite

Schist

Sandstone

Crystalline

Low porosity

Low permeability

Fractures

Crystalline

Low porosity

Low permeability

Fractures

High porosity

High permeability

Few fractures

Phase Diagram for Carbon Dioxide

• Storage below 800 m (waterhead) – Supercritical CO2

– Dense phase CO2 (500 to 800 kg/m3); Water is 1.3 to 2 times denser (heavier)

– Low viscosity 10-20 times less viscous – ~70 Mt CO2 used EOR

Storage below 800 m

CO2 Density is Defined by Storage Depth

Relation Between Time, Trapping Mechanisms and CO2 Storage Security

From IPCC SRCCS, 2005

Process Scales for CO2 Geologic Storage

•  Capacity, to store the intended CO2 volume

•  Injectivity, to receive the CO2 at the supply rate

•  Containment, to avoid or minimize CO2 leakage

Required Characteristics of Geological Media Suitable for Storage

of Fluids

Means Of CO2 Geologic Storage

Primary CCS Targets

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Example of A Cross Section

of a Sedimentary Basin

100 km

Northern California Sedimentary Basin

Example of a sedimentary basin with alternating layers of coarse and fine

textured sedimentary rocks.

Specific Types of Formations Within

Sedimentary Basins

•! Oil and gas reservoirs

–! Enhanced oil and gas recovery

–! Depleted oil and gas recovery

•! Deep formations that contain salt water

(saline aquifers)

•! Coal beds

Based on St. John et al., 1984

Types and Word Distribution of Sedimentary Basins

Plate Tectonics and CCS

Intra-cratonic, foreland and passive-margin basins

Sedimentary Basins

What Type of Rocks?

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Basic Concept of Geological

Sequestration of CO2

•! Injected at depths of 1 km or deeper

into rocks with tiny pore spaces

•! Primary trapping –! Beneath seals of low permeability rocks

Image courtesy of ISGS and MGSC

Courtesy of John Bradshaw

What Types of Rocks are Suitable

for CO2 Storage?

•! Igneous rocks –! Rocks formed from cooling magma

–! Examples •! Granite

•! Basalt

•! Metamorphic Rocks –! Rocks that have been subjected to high

pressures and temperatures after they are formed

–! Examples •! Schist

•! Gneiss

•! Sedimentary rocks –! Rocks formed from compaction and

consolidation of rock fragments

–! Example •! Sandstone

•! Shale

–! Rocks formed from precipitation from solution –! Example

•! Limestone

Granite

Schist

Sandstone

Crystalline

Low porosity

Low permeability

Fractures

Crystalline

Low porosity

Low permeability

Fractures

High porosity

High permeability

Few fractures

Unconventional… Basalts

• Capacity is immense • Chemical makeup favorable for mineralization reactions • Deposited like sedimentary rocks – Seals –  reservoirs –  If only 3% of basalt is suitable for injection

•  100 GtCO2 storage capacity

Unconventional… Coal

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Adsorption of Various Gases on Coal

Mineralization = Permanence

Storage Security & Permanence

• 

Basalt Sequestration (mineral trapping)

0

10

20

30

40

50

60

0 100 200 300 400 500

Time (years)

Sto

red

CO

2 (

kg

m-3

)

Hydrodynamic

Solubility

Mineral

=+Calcium -

Magnesium Silicate Rock + Carbonic Acid and

Water = Calcite or Magnesite

jmatter@ldeo.columbia.edu

Geologic Mineral Trapping

Rocks convert atmospheric CO2 (dissolved in surface waters) to stable, inert carbonate minerals Mineralization…. Naturally occurring

and is Stable Over Geologic Time

Reactive Rock Example (mineral trapping)

0%

20%

40%

60%

0 100 200 300 400 500

Time (years)

Po

rosit

y F

illin

g (

%)

Zeolites

Carbonates

Water

Clays

Super Critical CO 2

Time, days0 50 100 150 200 250

CO

2 Pressure, psi 0

200

400

600

800

1000

1200

1400

1600

1800Reactor 1Reactor 3

Rocky Coulee BasaltCoarse grain (0.85 to 2.0 mm)T=~100°C

Test TerminatedCalcite PrecipitationConfirmed by XRD Repressurized

to1456 psi

Long-term experiments showing transition from calcite to ankerite, Ca(Fe, Mg, Mn)(CO3)2

Concluding Remarks Regarding Site Selection

§  CO2 storage sites should be selected based on the safety and security of storage, their capacity and injectivity, ability to meet regulatory requirements including monitoring, accessibility and economics

§  Any assessment of CO2 storage capacity should carefully consider the processes involved, their spatial and temporal scales, the resolution of the assessment, and the available data and their quality

§  Sites should be properly characterized to meet regulatory and stakeholders requirements, particularly in regard to safety and security of storage