S. Bachu - Geologic Storage Site Selection and Characterization

7/28/2019 S. Bachu - Geologic Storage Site Selection and Characterization

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CO2 Storage-Site Screening, Selection and

Characterization

Dr. Stefan BachuDistinguished Scientist, CO2 Storage

Alberta Innovates Technology Futures

[email protected]

RECS 2013 Birmingham, AL

Associate Editor

(Storage)


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The Pathway to CO2 Capture and Storage


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CO2 Capture and Storage Chain

CaptureUnderground

Injection & StoragePipeline

TransportCompression


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We know how to do it!


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CO2 Capture and Storage

Sleipner North Sea,since 1996, 1 Mt CO2/yr

from an offshore gas plant

Worldwide activities: 8 active projects of which

5 capture CO2 from gasplants, 2 from power

plants and 1 from a coalgasification plant

>70 announced projects invarious stages ofplanning, design and

implementation, mostly in

US, Canada and China

In Salah- Algeria, since 2006, 1 Mt CO2/yr from anonshore gas plant, now discontinued


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CO2 Pipeline Network in the U.S.

Annual CO2 transport: ~ 50 Mt/year on ~6000 km pipeline


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Operational Stages of CO2 Storage

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


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Outline

o Relevant CO2 properties for CO2 storageo

CO2 storage assessment scales

o Basin and regional scale screening criteriao Local and site-scale screening criteria


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Relevant CO2 Properties,

CO2 Trapping Mechanisms,Means and Media

for CO2 Geological Storage


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Phase Diagram for Carbon Dioxide


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CO2 Density for Pressure and Temperature

Conditions in the Earth Crust


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Temperature (oC)

0

500

1000

1500

2000

2500

3000

0 20 40 60 80 100

Depth(m)

Pressure (bar)

0

500

1000

1500

2000

2500

3000

0 100 200 300 400

Depth(m)

T = 10oC + 25oC/1,000 m x 1,250 m

= 41.25oC

1,250 m

Ts=10oC

p= 105 Pa + 1,000 kg/m3 x 9.81 m/s2*1,250 m

= 12.36 MPa (123.6 bar)

1,250 m

Watertable = 0 m

Example of Subsurface Temperature and

Pressure for CO2 Storage


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Storage below 800 mv Supercritical CO2v Dense phase CO2 (500 to 800

kg/m3); Water is1.3 to 2 times

denser (heavier)v Low viscosity (0.04 to 0.06

MPas); Water is 10-20 timesmore viscous

Rule-of-thumbv Depends on P and T profilev Will vary from site to site

Watertable depthMean annual surface

temperature and geothermalgradient

Storage below 800 m

Storage Depth is Defined by CO2 Density


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PipelineTransportation

(31.0oC, 7.38 MPa)

Leak in the atmosphere

SupercriticalFluid

1,600 m

1,250 m900 m

500 m

200 m

CO2 Phases in a Transportation and

Storage System


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Trapping of CO2 in the Pore Space

at Irreducible Saturation


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Carbon Dioxide Solubility in WaterIn pure water In brine


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Sequence of Geochemical Reactions

between CO2

and

Formation Water and Rocks

CO2(g) CO2(aq) CO2(aq) + H2O H2CO3(aq)

1. Solubility Trapping

H2CO3(aq) HCO

3(aq) + H+ HCO3(aq) CO2-3(aq) + H+

2. Ionic Trapping

CO2-3(aq)+ Ca2+ CaCO3(s)

HCO3(aq) + Ca2+ CaCO3(s) + H+

3. Mineral Trapping


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Adsorption of Various Gases on Coal


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Trapping Mechanisms for CO2Physical Trapping (in free phase)

In large, man-made caverns

In solution in formation fluids (oil or water)

Chemical Trapping (in a different phase)

Adsorbed onto organic material in coals and shales

As a mineral precipitate

In the pore space (as CO2) in structural and stratigraphic trapsat irreducible saturation (immobile) in long-range, regional-scale flow systems (open aquifers)


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Temporal Scales of CO2 Injection

and Geological Storage Processes


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Relation between Time, Trapping

Mechanisms and CO2 Storage Security

From IPCC SRCCS, 2005


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Process Scales forCO

2Geological Storage


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Required Characteristics of Geological MediaSuitable for Storage of Fluids

Capacity, to store the intended CO2

volume

Injectivity, to receive the CO2 at the supply rate

Containment, to avoid or minimize CO2 leakage


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Igneous rocksv Rocks formed from cooling magma

Granite Basalt

Metamorphic Rocksv Rocks that have been subjected to high

pressures and temperatures after they

are formed Schist Gneiss

Sedimentary rocksv Rocks formed from compaction and

consolidation of rock fragments

Sandstone Shale

v Rocks formed from precipitation fromsolution

Limestone

Granite

Schist

Sandstone

Crystalline

Low porosity

Low permeability

Fractures

Crystalline

Low porosityLow permeability

Fractures

High porosity

High permeability

Few fractures

Rocks Suitable for CO2 Storage


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Geological Media Suitable for CO2 StoragePorous and permeable rocks (sandstone andcarbonate) overlain by tight rocks (shales and evaporiticbeds):Oil and gas reservoirsDeep saline aquifersCoal beds

Salt caverns

All are geological media found ONLY in sedimentary basins


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Types and World Distribution of Sedimentary

Basins

Based on St. John et al., 1984


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Means for CO2 Geological Storage

In oil reservoirs in enhanced hydrocarbon recovery

In coal beds in enhanced coalbed methane recovery

In depleted oil and gas reservoirs

As a byproduct in energy production operations

In disposal operations

In deep saline aquifers

In salt caverns (mainly as a buffer in CO2 collectionand distribution systems)


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Means of CO2 Geological Storage


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from IPCC, 2005 Three primary conditions Sedimentary rocks with storage reservoirs and seals Pressure and temperature > critical values (31oC, 7.8 MPa) Not a source of drinking water

Prospectivity of Sedimentary Basins for

CO2

Storage


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Controversial Storage MediaAmong the media proposed for CO2 storage:Storage in coal beds:

Has never been successfully demonstrated Uneconomic coals have not been defined

Storage in shales rich in organic material: Based on the same principles as storage in coal beds Has not been attempted and demonstrated Will require fracturing the shale, which constitute the caprock

for hydrocarbon reservoirs and deep saline aquifers

Storage in basalts (based on rapid geochemical reactions) Very controversial because of basalts high porosity and

permeability A test is under way in western Washington state


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CO2 Storage Assessment Scales


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Site selection criteria are the criteria by which a site is assessed,evaluated, judged, and, in the case of multiple possible sites, ranked

for final selection and qualification

Site characterization represents a collection of types of data andinformation needed to reach the necessary understanding and

confidence that the proposed storage site is safe and acceptable

Site selection and characterization depend on the scale of theassessment

Basic Principles 1


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Assessment Scales and Resolution

Country: high level, minimal dataBasin: identify and quantify storage potentialRegional: increased level of detail, identify prospectsLocal: very detailed, pre-engineering site selectionSite: engineering level for permitting, design and

implementation

Note: Depending on the size of a country in relation to its sedimentarybasin(s), the order of the top two or three may interchange


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Relationship Between Assessment Scale

and Level of Detail and Resolution


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Primary Characteristics of Geological

Media Suitable for CO2

Storage

Capacity: to store the intended CO2 volumeInjectivity: to receive the CO2 at the supply rateContainment: to prevent, avoid or minimize CO2 leakageHowever, if capacity and/or injectivity are insufficient, some

measures can be taken (e.g., use multiple and/or horizontal wells,

use several storage sites, store less CO2)

If containment is defective, then the prospective site is

disqualified!


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Basic Principles 2

Site characterization is an iterative, non-linear processrunning through all the operational stages of CO2 storage

Monitoring is a key element in site operation, closure andpost-closure, likely to be a permitting requirement

Storage safety and security is a common thread throughoutall the stages of the operational chain and has to be

demonstrated when applying for tenure of the storage unit

and permit to operate, during operations, and after cessation

of injection to complete site abandonment


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Basin and/or Regional Scale Screening


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Flow of Formation Waters

in Sedimentary Basins

Driven by sediment compaction on marine shelves

Driven by tectonic compression in orogenic belts

Driven by erosional and/or glacial rebound inforeland and intra-cratonic basins

Driven by topography in intra-montane, forelandand intra-cratonic basins

Driven by hydrocarbon generation andother internal overpressuring processes


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Types of Fluid Flow in Sedimentary Basins


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Risk of Leakage in Sedimentary Basins

(Hitchon et al., 1999)


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Preferred Flow Systems

Deep, regional scale, driven by topography

or erosional rebound


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Geothermal Regime in Sedimentary Basins

Basin type, age and tectonism

Proximity to crustal heat sources

Basement heat flow

Depends on:

Temperature at the surface

Thermal conductivity and heatproduction of rocks


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Plate Tectonics and Earths Heat Flow


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Surface Temperature for Sedimentary Basins

Marine basins: 3-4 oC at the bottom ofthe sea/ocean

Continental (sub) Arctic and (sub) Antarctic basins:-2 oC below the permafrost

Continental temperate basins:4-10 oC depending on latitude and altitude

Continental tropical basins: 10-25o

C dependingon latitude and altitude


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Variation with Depth and Geothermal Regime

of Carbon Dioxide Density


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Sedimentary Basins by Geothermal Regime

Low surface temperature and/or geothermal gradients

- more favorable (higher CO2 density, at shallower depths)

High surface temperature and geothermal gradients- less favorable (lower CO2 density, larger depths needed)

Cold basins:

Warm basins:


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Basin Maturity

Defined by fossil-energy potential (oil and gas, coals)and degree of exploration and production

Rich in energy resources, advanced production

Rich in resources, in exploration & early production stage

No or poor in hydrocarbon resources

Mature:

Immature:

Poor:


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Industry Maturity and Infrastructure

Access roads, pipelines, wells (e.g., Texas, Alberta)

Drilling and production platforms (e.g., North Sea)

Developed continental basins:

Developed marine basins:


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Eliminatory Criteria for Sedimentary BasinsCriterion Unsuitable Suitable

1 Depth < 1000 m >1000 m

2 Aquifer-seal pairs Poor (few,discontinuous)

Intermediate, excellent

3 Pressure regime Overpressured Hydrostatic

4 Seismicity High and very high Very low to moderate

5 Faulting and fracturing Extensive Limited to moderate

6 Hydrogeology Shallow, short flowsystems

Intermediate, regional-scale flow systems

7 Areal size 2500 km2

8 Legal accessibility Forbidden Allowed


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Desirable Characteristics of Sedimentary BasinsCriterion Undesirable Desirable

1 Within fold belts Yes No

2 Significant diagenesis Present Absent

3 Geothermal regime Warm basin Cold basin

4 Evaporites Absent Present

5 Hydrocarbon potential Absent/small Medium/giant

6 Industry maturity Immature Mature

7 Coal seams Absent, shallow orvery deep

Between 400 m and 800m depth

8 Coal rank Lignite/Anthracite (sub) Bituminous

9 Coal value Economic Uneconomic

10 On/offshore Deep offshore Onshore, shallow

11 Climate Harsh Moderate

12 Accessibility No or difficult Good

13 Infrastructure Absent/undeveloped Developed

14 CO2 sources


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Cross Sectional Representation

of Sedimentary Basinsacross North America


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Seismicity in Canada


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Canadas Sedimentary Basins


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Local and Site-Scale Screening Criteria


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Basic Principles 3

Sites must pass the basin-scale eliminatory criteria, and should broadlypossess basin-scale desirable characteristicsIn addition, sites must pass and/or meet additional criteria that fallbroadly into five categories:

Capacity and injectivityConfinement, i.e., safety, security and environmental acceptabilityLegal and regulatory restrictionsEconomicSocietal (public acceptance)

The same criteria can be organized into:Eliminatory criteria: sites are eliminated if they dont meet these criteriaSelection criteria: sites are selected if they meet most or the preferred ofthese criteria, depending on local circumstances


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Eliminatory Site Selection Criteria - 1

1. Legally inaccessible (in protected areas)2. Legally unreachable (right of access cannot be secured)3. Legally unavailable (e.g., equity interest held by third parties)4. Physically unavailable (e.g., a hydrocarbon reservoir in production, an

aquifer used for geothermal energy or for natural gas storage)

5. Located in high-density population areas flexible6. Potentially affecting other natural, energy and mineral resources and

equity


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Eliminatory Site Selection Criteria - 2

7. Within the depth of protected groundwater8. In hydraulic communication or contact with protected groundwater9. Located at shallow depth (


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Site Selection Criteria - 1

For efficacy of storage:

1. Sufficient capacity and injectivity:they are not independent,injectivity may limit capacity!

2. Sufficient thickness3. Low temperature4. Favorable pressure and hydrodynamic regime


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For safety and security of storage:

5. Low number of penetrating wells6. Presence of multi-layered overlying system of aquifers and

aquitards (secondary barriers to upward CO2 migration)

7. Potential for attenuation of leaked CO2 near and at surface


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For cost:

8. Accessibility and infrastructure (location, terrain, climate,right of access, avoidance of populated/protected areas)

9. Transportation economics (distance from source, pipelinesor shipping facilities, compression and site delivery)

10.Storage economics (site facilities, wells and compression,operational and environmental monitoring)


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Additional Site Selection Criteria?

DepthThicknessPorosityPermeabilityWater salinityThese have been suggested in the past, but they are implicit in the

criteria of capacity, injectivity, and protection of groundwater and/ormineral resources

They still can be used as selection criteria, but they are not completely

independent and changes in one may affect another


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Critical Site Qualification CriteriaCriterion Eliminatory

ConditionAcceptable Condition

1 Sealing Poor, faulted,breached,

Multi-layered system

2 Pressure gradients >14 kPa/m < 12 kPa/m

3 Monitoring potential Absent Present

4 Affecting groundwater Yes No

A sitemust passall these criteria to be considered for CO2 storage


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Essential Site Qualification CriteriaCriterion Eliminatory

ConditionAcceptable Condition

1 Seismicity High Moderate and less

2 Faulting and

fracturingintensity

Extensive/high Limited to moderate

3 Flow systems Short and/or incommunication with

protected groundwater

Intermediate and regionalscale

A siteshould passall these criteria to be considered for CO2 storage,but exceptions can be made


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Desirable Site Qualification Criteria - 1

Criterion Unfavorable Favorable

1 Within fold belts Yes No

2 Adversediagenesis

Significant Low to moderate

3 Geothermalregime

G 35 C/km and/or highTs

G < 35 C/km and lowTs

4 Temperature < 35 C 35 C

5 Pressure < 7.5 MPa 7.5 MPa

A siteshould meetas many as possible of these criteria;if too few are being met, then maybe it should be rejected


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Desirable Site Qualification Criteria - 2

Criterion Unfavorable Favorable

6 Thickness < 20 m 20 m

7 Porosity < 10% 10%

8 Permeability < 20 mD 20 mD

9 Caprockthickness

< 10 m 10 m

10 Well density High Low to moderate


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Site Characterization Objectives - 1

1. 3-D structure of the sedimentary succession from the storage unit toground surface

2. Geology of the sedimentary succession from the storage unit toground surface

3. Rock properties4. Mineralogical, chemical and mechanical characteristics of all system

components

5. Hydrogeology and geothermics


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Broad Site Characterization - 2

7. Planar discontinuities such as faults and fractures8. Fault and fracture characteristics9. In-situ conditions of P, T and stress10.Fluid compositions and PVT behaviour11.Linear features such as wells12.Reservoir and wells history


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Concluding Remarks

Regarding Site Selection

CO2 storage sites should be selected based on the safety andsecurity of storage, their capacity and injectivity, ability to meet

regulatory requirements including monitoring, accessibility and

economics

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

Sites should be properly characterized to meet regulatory andstakeholders requirements, particularly in regard to safety and

security of storage


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References Regarding Site Selection

1. Screening and ranking of sedimentary basins forsequestration of CO2 in geological media in response to

climate change. Bachu. S., Environmental Geology, v. 44, no. 3, p.277-289, doi: 10.1007/s00254-003-0762-9

2. Screening and selection criteria, and characterisation for CO2geological storage. Bachu, S. In: Developments and Innovation in

Carbon Dioxide (CO2) Capture and Storage Technology, Vol. 2 (M.Maroto-Valer, ed.), Woodhead Energy Series No. 16, Woodhead

Publishing Ltd., p. 27-56, 2010.


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References Regarding

Storage Capacity Estimation

1.CO2 storage capacity estimation: Methodology and gaps. Bachu, S.,J. Bradshaw, D. Bonijoly, R. Burruss, S. Holloway, N.P. Christensen and O-

M. Mathiassen. International Journal of Greenhouse Gas Control, v. 1, no.4, p. 430-443, doi: 10.1016/S1750-5836(07)00086-2, 2007.

2.U.S. DOE methodology for the development of geologic storagepotential for carbon dioxide at the national and regional scale.AngelaGoodman, Alexandra Hakala, Grant Bromhal, Dawn Deel, Traci Rodosta,

Scott Frailey, Mitchell Small, Doug Allen, Vyacheslav Romanov, Jim Fazio,Nicolas Huerta, Dustin McIntyre, Barbara Kutchko and George Guthrie.

International Journal of Greenhouse Gas Control, v. 5, doi: 10.1016/j.ijggc.

2011.03.010.


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Contact

Dr. Stefan Bachu

Alberta Innovates Technology [email protected]

Documents

S. Bachu - Geologic Storage Site Selection and Characterization