Presentation by Neil Wildgust of the Global CCS Institute at the 2015 CCUS Workshop for CO2 Storage, January 22 at University of Sonora, Hermosillo

1. Neil Wildgust
Principal Manager – Geological Storage
Global CCS Institute
INTRODUCTION TO CAPTURE, USE AND GEOLOGICAL STORAGE OF CO2
January 22-23 2015
University of Sonora, Hermosillo
SUPPORTED BY:

2. CO2 Storage Resource/Capacity and
Storage Efficiency in Deep Saline
Formations
Presentation prepared by:
Ed Steadman
Deputy Associate Director for Research
Energy & Environmental Research Center
SUPPORTED BY:

3. PRESENTATION OUTLINE
SUPPORTED BY:
• What Is Storage
Resource/Capacity?
• Levels of Assessment
• Volumetric vs. Dynamic
• Open vs. Closed Systems
• Equations
• CO2 Storage Efficiency
• Scale of Assessment
• Local and Regional Volumetric
Storage Coefficients

4. TERMINOLOGY
SUPPORTED BY:
• Effective Storage Resource:
Represents the fraction of the pore
volume of a sedimentary rock
formation available for carbon
dioxide (CO2) storage after
technical constraints have been
applied (Gorecki and others, 2009).
• Practical Storage Capacity:
The storage capacity can be
estimated by applying economic
and regulatory constraints to the
effective storage resource.
Practical storage capacity may be
further broken down similarly to
petroleum industry standards
(Gorecki and others, 2009).

5. PROPOSED CLASSIFICATION SYSTEM
SUPPORTED BY:
• Theoretical storage
resource
• Accounts for the total
pore space within the
area of assessment.
• Equivalent to a rough
original-oil-in-place
(OOIP) or ore estimate.

6. PROPOSED CLASSIFICATION SYSTEM (cont.)
SUPPORTED BY:
• Characterized storage
resource
• Estimate that takes
spatial variability and
geological
heterogeneity into
account.
• Equivalent to a refined
OOIP or total ore
estimate after sufficient
exploration.

7. PROPOSED CLASSIFICATION SYSTEM (cont.)
SUPPORTED BY:
• Effective storage
resource
• Storage resource that is
technically feasible to
utilize.
• Applies factors that limit
storage based on the
manner in which CO2 fills
the available pore space.
• Roughly equivalent to
planned production
estimates with a recovery
factor or expected
minable reserves.

8. PROPOSED CLASSIFICATION SYSTEM (cont.)
SUPPORTED BY:
• Practical storage
capacity
• Fits the U.S. Department
of Energy (DOE)
definition of capacity.
• Economically and
technically viable
storage opportunities.
• Roughly equivalent to
strategic reserves or
operational fields or
mines.

9. CO2 STORAGE RESOURCE/CAPACITY
METHODOLOGIES
SUPPORTED BY:
• Static CO2 storage resource/capacity
methodologies:
• DOE, Carbon Sequestration Leadership Forum
(CSLF) and IEA Greenhouse Gas R&D Programme
(IEAGHG) methodology.
• U.S. Geological Survey (USGS) methodology.
• Closed system, compressibility methodology.
• Dynamic CO2 storage capacity methodologies
• Concerned with pressure, injectivity, timing of injection
projects, etc.
• Based largely on detailed CO2 injection simulations on
the site.

10. OPEN AND CLOSED SYSTEMS
SUPPORTED BY:
• Large, continuous,
permeable, little to no
pressure feedback
• Compartmentalized,
large pressure
feedback
• Most realistic, some
combination of the two

11. COMPARIOSN OF OPEN-SYSTEM METHODOLOGIES
SUPPORTED BY:
• Fundamentally, the CSLF and DOE methods are the same
method.
• Any storage volume estimated with one method can be
compared to the other, as long as the assumptions made are
the same.
 
EE
E
E
CSLFCODOECO
wirrCE
CwirrCSLFCO
EDOECO
VV
SCE
CShAV
EhAV
,,
,
,
22
2
2
)1(
1







12. CLOSED-SYSTEM METHODOLOGY
SUPPORTED BY:
• Assumes no pressure or fluid can leave the system.
• Underestimates storage resource in most cases.
• In consolidated formations, this may represent an
efficiency term of less than 1%.
• Storage resource can be increased by producing
formation waters.
pccE
EhAV
pwcomp
compcompCO


)(
,2


13. CO2 STORAGE EFFICIENCY
SUPPORTED BY:
• Represented as a
fraction of the pore
space.
• Describes how
CO2:
• Displaces in situ
fluids (brine, oil,
gas, etc.).
• Pressurizes the
formation.
• Or is a utilization
term in the case
of enhanced oil
recovery (EOR).
Gorecki and others, 2009

14. CO2 STORAGE EFFICIENCY (cont.)
SUPPORTED BY:
Effective Resource
Where:
• = DOE storage coefficient from the DOE Atlas, 2006, 2008, and 2010.
• = Fraction of the entire area that is amenable to CO2 injection.
• = Volumetric displacement efficiency – represents the fraction of the pore space immediately around the injection
well that is contacted by injection CO2.
• = Areal displacement efficiency = Fraction of the pore space in the immediate area surrounding an injection well that can be
contacted by CO2.
• = Vertical displacement efficiency = Fraction of the vertical cross section (thickness), with the volume defined by the CO2 plume from
a single well.
• = Gravity = Fraction of the net thickness that is contacted by CO2 as a consequence of density difference between CO2 and in situ
water.
• = (1 – Swave) = Microscopic displacement efficiency = Portion of CO2-contacted pore volume that can be replaced by CO2. ED is directly
related to irreducible water saturation in the presence of CO2.
EDOECO EhAV E
 ,2
  CwirrCSLFCO CShAV E
 1,2

DVolGeolE EEEE 
gIAVol EEEE 
AE
IE
DE
gE
tot
eff
g
n
t
n
Geol h
h
A
A
E



)1(
)1(
wirr
wave
GeolVolC
S
S
EEC


 )1( wirrCE SCE 
EE CSLFCODOECO VV ,, 22


15. OPEN SYSTEMS
SUPPORTED BY:
• Open systems are governed by
displacement.
(DOE, 2008, 2010)
(Gorecki and others, 2009)
Holloway and others, 2004
Brantjes, 2008

16. CLOSED SYSTEMS
SUPPORTED BY:
Closed systems are
governed by compression.
(DOE, 2008, IEAGHG, 2009)
(Gorecki and others, 2009)

17. SCALE OF ASSESSMENT
SUPPORTED BY:
• When performing
resource/capacity
estimates, the scale must
be considered.
• Local and site-specific
levels of assessment –
high data quality.
• Large-scale assessments
– decreased confidence. Scale of assessment pyramid, separating the
political/geographical definitions from the
physical/geologic.

18. STORAGE RESOURCE ESTIMATION IN DEEP
SALINE FORMATIONS
SUPPORTED BY:
• Data source
• Examined worldwide field-based carbon capture and storage
(CCS) projects.
• Compiled a database with reservoir properties from hydrocarbon
reservoirs – Average Global Database (AGD).
• Evaluation strategy
• Constructed homogeneous models to test the strength of single
parameters on storage resource.
• Constructed heterogeneous models to test a wide range of
parameters under different geologic settings on storage resource.
• Storage coefficients were developed at the site-specific level and
then extrapolated out to the formation level.

19. HETEROGENEOUS MODEL TESTING
SUPPORTED BY:
• Heterogeneous models were
developed to determine the
effects of lithology, depositional
environment, and structure on
the storage coefficients.
• Three lithologies, ten
depositional environments, and
five structural settings were
tested.
• In all, 195 simulations were run
to determine the effects of a wide
range of variables on resource
estimates and storage
coefficients.

20. DETERMINING STORAGE COEFFICIENTS WITH
NUMERICAL SIMULATION
SUPPORTED BY:
• When to determine
storage coefficient
• Model size
• Injection rate and volume
• Trapping processes
• CO2 plume definition
• Accessible volume

21. STORAGE COEFFICIENTS AT DIFFERENT SCALES
SUPPORTED BY:
• Storage coefficients were developed at two scales, site-
specific and formation level.
• Site-specific coefficients were extrapolated out to
formation-level coefficients.

22. SITE-SPECIFIC STORAGE COEFFICIENTS
SUPPORTED BY:
• Storage coefficient typical range at
the site-specific level was about 4%
to 17%, with an 80% confidence
interval.
• Structural traps greatly increase the
storage coefficient on the site-
specific level.
• These simulations were run at the
P50 depth (2336 m); at the P10
depth (895 m), the storage
coefficients are reduced by about
50%, and at the P90 depth (3802 m)
are increased by about 50%.

23. FORMATION-LEVEL STORAGE COEFFICIENTS
SUPPORTED BY:
P10, P50, and P90 Storage Coefficients Calculated EE and CC ∗ (1 − Swirr)
for the Formation Level for Different Lithologies
Lithology P10 P50 P90
Clastics 1.86% 2.70% 6.00%
Dolomite 2.58% 3.26% 5.54%
Limestone 1.41% 2.04% 3.27%
All 1.66% 2.63% 5.13%
• Effective storage coefficients on the formation level were determined
based on the P50 An/At and hn/hg.
• Formation-specific geologic properties should be used if they are known.

24. BASIN AND/OR REGIONAL SCREENING
SUPPORTED BY:
• Determine which formations
are deep enough to allow CO2
to reside in dense phase
(super critical), generally
deeper than 800 m.
• In some regions, target
formation water must have
salinity greater than 10,000
ppm (regulatory constraint).
• Should have a laterally
continuous impermeable seal.

25. BASIN AND/OR REGIONAL SCREENING (CONT.)
SUPPORTED BY:
Suitable formation = intersection of area >800 m deep and area >10,000 ppm TDS = An

26. ESTIMATING FORMATION-SCALE CO2 STORAGE
RESOURCE
SUPPORTED BY:
DOE method (2010)
• 𝑀 𝐶𝑂2
= 𝐴 𝑡 ∗ ℎ 𝑔 ∗ 𝜑 𝑡 ∗ 𝐸 ∗ 𝜌 𝐶𝑂2
Open System
• 𝐸 𝐸 = 𝐸 𝑔𝑒𝑜𝑙∗ 𝐸 𝐷
• 𝐸 𝑔𝑒𝑜𝑙 = 𝐸𝐴 𝑛/𝐴 𝑡
∗ 𝐸ℎ 𝑛/ℎ 𝑔
∗
𝐸 𝜑 𝑒𝑓𝑓/𝜑 𝑡𝑜𝑡
• 𝐸 𝐷 = 𝐸 𝑣𝑜𝑙 ∗ 𝐸 𝑑
Closed System
• 𝐸𝑐𝑜𝑚𝑝 = ∆𝑃 ∗ (𝑐 𝑤 + 𝑐𝑓)

27. ESTIMATING FORMATION-SCALE CO2 STORAGE
RESOURCE (CONT.)
SUPPORTED BY:
• Pore volume was clipped to
the effective porosity.
• The appropriate efficiency
term (ED) was applied.
• A low (P10), mid (P50), and
high (P90) storage resource
was calculated for each
saline system.
Saline Formation Displacement Efficiency Terms, ED (U.S. Department of Energy, 2010)
Lithology P10 P50 P90
Clastics 7.4% 14% 24%
Dolomites 16% 21% 26%
Limestones 10% 15% 21%

28. KEY DOCUMENTS
SUPPORTED BY:
IEA Greenhouse Gas R&D Programme, Development of Storage
Coefficients for Carbon Dioxide Storage in Deep Saline Formations, Report
No. 2009/13.
This study examined existing methodologies to estimate CO2 storage potential in
deep saline formations and developed coefficients that can be applied to assess
the effective storage capacity of these types of reservoirs. A framework to classify
various levels of CO2 storage resource potential was also developed.
IEA Greenhouse Gas R&D Programme, 2012, Extraction of Formation
Water from CO2 Storage, Report No. 2012/12.
This study investigated the possibility of using formation water extraction as a
method of optimizing the geologic storage of CO2. Four cases studies were
performed using geocellular modeling and simulation. The potential beneficial
uses of extracted water were also considered.

29. KEY DOCUMENTS (CONT)
SUPPORTED BY:
IEA Greenhouse Gas R&D Programme, CO2 Storage Efficiency in Deep Saline
Formations: A Comparison of Volumetric and Dynamic Storage Resource Estimation
Methods, in press.
This study examines the validity and applicability of current CO2 storage resource estimation
methods by directly comparing the volumetric CO2 storage resource with that estimated using
numerical simulation (i.e., dynamic storage resource) for two deep saline systems. The effect
of site-specific factors (e.g., pressure interference and well location) as well as optimization
scenarios (e.g., water extraction) on CO2 storage resource estimates were also investigated.
Nelson, C.R., Evans, J.M., Sorensen, J.A., Steadman, E.N., and Harju, J.A., Factors
Affecting the Potential for CO2 Leakage from Geologic Sinks, Plains CO2 Reduction
(PCOR) Partnership topical report for U.S. Department of Energy National Energy
Technology Laboratory and multiple clients, Grand Forks, North Dakota, Energy &
Environmental Research Center, October 2005.
This study examined the physical and chemical properties of CO2 and how they relate to its
ability to be trapped and remain contained in geologic sinks for the purpose of long-term
storage. Analog studies were conducted that examined existing large-scale geologic
concentrations of CO2 and hydrocarbons as a proxy to investigate potential leakage processes
during the geologic storage of CO2.

30. KEY DOCUMENTS (CONT)
SUPPORTED BY:
Atlas IV (2012) provides an update on the CO2 storage potential
in the United States and showcases updated information on
Regional Carbon Sequestration Partnership (RCSP) field
activities and new information from the site characterization
projects. Atlas IV outlines DOE’s Carbon Storage Program and
its carbon capture, utilization, and storage (CCUS)
collaborations, along with worldwide CCUS projects and CCUS
regulatory issues. The data used to create the Atlas IV resource
estimates are available in interactive form on the National
Carbon Sequestration Database and Geographic Information
System (NATCARB) Web site.
Atlas III (2010) provides a coordinated update of CCS
potential across most of the United States and portions of
Canada. The primary purpose of Atlas III was to update
CO2 storage potential for the United States and Canada,
and to provide updated information on RCSP field
activities. Atlas III also provides a summary of the
methodology for development of geologic storage
estimates for CO2.

31. REFERENCES
SUPPORTED BY:
• Carbon Sequestration Leadership Forum, 2005, A task force for review and development of standards with regards to storage capacity
measurement—Phase I: CSLF-T-2005-9 15, August 2005, 16 p. www.cslforum.org/publications/documents/PhaseIReportStorage
CapacityMeasurementTaskForce.pdf (accessed June 2009).
• Carbon Sequestration Leadership Forum, 2007, Estimation of CO2 storage capacity in geological media—Phase II report: June 15, 2007.
www.cslforum.org/publications/documents/ PhaseIIReportStorageCapacityMeasurementTaskForce.pdf (accessed June 2009).
• Carbon Sequestration Leadership Forum, 2008, Comparison between methodologies recommended for estimation of CO2 storage capacity in
geologic media—Phase III report: April 21, 2008. www.cslforum.org/publications/documents/PhaseIIIReportStorageCapacity
EstimationTaskForce0408.pdf (accessed June 2009).
• Gorecki, C.D., Sorensen, J.A., Bremer, J.M., Ayash, S.C., Knudsen, D.J., Holubnyak, Y.I., Smith, S.A., Steadman, E.N., and Harju, J.A., 2009,
Development of storage coefficients for carbon dioxide storage in deep saline formations, IEA Greenhouse Gas R&D Programme Technical
Study 2009/13.
• IEA Greenhouse Gas R&D Programme, November 2008, Aquifer storage—development issues: Report No. 2008/12.
• IEA Greenhouse Gas R&D Programme, Development of storage coefficients for carbon dioxide storage in deep saline formations, Report No.
2009/13.
• IEA Greenhouse Gas R&D Programme, A comparison of volumetric and dynamic CO2 storage resource estimation methodologies in deep
saline formations, in press.
• Kopp, A., Class, H., and Helmig, R., 2009, Investigations on CO2 storage capacity in saline aquifers—part 2—estimation of storage capacity
coefficients: International Journal of Greenhouse Gas Control, Elsevier, in press.
• Society of Petroleum Engineers, World Petroleum Council, and American Association of Petroleum Geologists, 2007, Petroleum resources
management system.
• U.S. Department of Energy National Energy Technology Laboratory Office of Fossil Energy, 2007, Carbon sequestration atlas of the United
States and Canada.
• U.S. Department of Energy National Energy Technology Laboratory Office of Fossil Energy, 2008, Carbon sequestration atlas of the United
States and Canada.
• U.S. Department of Energy National Energy Technology Laboratory, 2010, Carbon sequestration atlas of the United States and Canada –
Third Edition.
• Zhou, Q., Birkholzer, J.T., Tsang, C.F., and Rutqvist, J., 2008, A method for quick assessment of CO2 storage capacity in closed and
semiclosed saline formations: International Journal of Greenhouse Gas Control, v. 2, no. 4, p. 626–639.

32. CONTACT INFORMATION
SUPPORTED BY:
Energy & Environmental Research Center
University of North Dakota
15 North 23rd Street, Stop 9018
Grand Forks, ND 58202-9018
World Wide Web: www.undeerc.org
Telephone No. (701) 777-5279
Fax No. (701) 777-5181
Ed Steadman, Deputy Associate Director for Research
esteadman@undeerc.org