geological storage - risk assessment & monitoring€¦ · geological storage - risk assessment...
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www.slb.com/carbonservices/www.slb.com/carbonservices/
Geological Storage -Risk Assessment & Monitoring
IEA GHG Summer School, Norway
David White 24th August 2010
Schlumberger - over 80 years of history & technology
First electrical log run by Marcel and Conrad Schlumberger
Pechelbronn, Alsace, FranceS t b 5 1927September 5, 1927
Schlumberger today
People:● 80,000● 140 Nationalities● Working in over 80 countries
Services:● Reservoir characterization● Reservoir characterization● Reservoir production● Drilling & Measurements● Integrated Project Management
2009 Financials:● $22.7 billion revenue● $3.1 billion net● > $800 million on
Research & Development
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Schlumberger Carbon ServicesHighlights
People• A full Asset team dedicated to CO2 storage• >100 experienced technical staff
Experience in CO2 storage• More than 10 years experience in CO2 storage• Numerous ongoing projects worldwide including the • Numerous ongoing projects worldwide including the
regional partnerships in the USA, the Otway project in Australia, Ketzin in Europe.
Technology for CO2 storage• Unique set of process and technologies for CO2
storage• Dedicated research and engineering activities • More than 100 publications on CCS
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Global CO2 Storage Sites/Projects with Schlumberger Activity
Weyburn, CanadaSnøhvit, Barent Sea
Sleipner, North Sea
>60 CCS projects/studies globally
In Salah, AlgeriaGorgon Field, 130 km offshore NW AustraliaLarge
CCS projects
Large CCS
projects
Global CO2 Storage Sites/Projects with Schlumberger Activity
American Electric Power Company, Inc. (Ohio)
North Sea customer A - 2009
North Sea customer B - 2009PGE Belchatow - 2010
Vattenfall Jaenschwalde - 2010
Illinois Basin - Decatur Project - 2009
Southern Company Services, Inc. (Alabama)
Repsol Spain - 2009
Reggane, Algeria - 2009
Site pre-selection for ENI (4 sites) - 2008
CO2CRC – Otway Project – 2006-2010
Lassie, Australia
>60 CCS projects/studies globally
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Risk assessment and Monitoring for CO2 storage!
Why Monitor? – Manage Risk
Risk =
“ (Impact of Undesirable Occurrence)x x
(The Probability of its Occurrence)”
But it is not that simple……
Risk Perception Public vs. Experts
Public Feels - The Dread Factor- reacts very negatively to “worst-case” risk assessments,
Public: Risk Size= (“Known” factor)*(”Dread” factor)
Experts Calculatep- tend to rely on quantifiable “realist” perspectives,
Risk Size= (Probability)*(Loss)
Expert risk studies are rarely effective for convincing the public that a proposed project is safe.
Thesis by Gregory Singleton, MIT May 2007
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Risk Perception Public vs. Experts
Public Feels - The Dread Factor- reacts very negatively to “worst-case” risk assessments,
Public: Risk Size= (“Known” factor)*(”Dread” factor)
Experts Calculatep- tend to rely on quantifiable “realist” perspectives,
Risk Size= (Probability)*(Loss)
Expert risk studies are rarely effective for convincing the public that a proposed project is safe.
Thesis by Gregory Singleton, MIT May 2007
CCS Risk Types
GENERAL RISKS
● Public acceptance● Economic● Legal
TECHNICAL RISKS:
Key Concerns: Leakage & Seismicity
● Extreme events (major releases)● Ground fresh water resources contamination● Soil contamination● Leaks
● Risk Acceptance Criteria● Standards● Regulations and Policies
Risks can be managed – we do it all the time
● Evaluate & Understand● Model & Simulate● Measure & Monitor● Mitigate ● Experiment and
Demonstrate
(I bet they tried it with a dummy first ……and it might be a fake!)
http://www.youtube.com/watch?v=UXXC2etJeZQ
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What do we need?
Finding the right Storage Site
Injectivity:The ease with which the CO2can be injected
Other:• Environment• Infrastructure• Regulation• Public opinion• Finance
…the best risk reduction approach is to choose the right site in the first place
Capacity:The amount of CO2 that can be safely stored
Containment:The ability to store CO2safely and permanently
CO2 Monitoring – 3 objectives
BoundariesBoundaries
ContainmentContainment
#1: Watch stored CO2
#2: Watch possible leakage paths
#3: Monitor the environmentWell Integrity
Sealed fault
Monitoringwell
Abandonedwell
Monitoringwell
CO2injectionwell
Freshwateraquifer
Drawing from the Oilfield: Static and Dynamic Modeling Workflow
Surface imaging Mapping
Data inputLog interpretationand correlation
History match
Fault and Fracture modelling
3D Geological model Reservoir and Aquiferproperty population
3-D flow simulationGeochemistryGeomechanics
ECLIPSE
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Surface imaging MappingEM survey interpretationData input
Information managementGIS database
Log interpretationWell correlationSurface identificationSurface/subsurface interaction
CalibrationHistory matchPost processingPresentation
Data analysisFacies modellingFault modellingFracture modellingHydrodynamic test analysis
CO2 Storage Site Modelling Workflow
Uncertainty analysisUpscaling processesReservoir and Aquifer property population
3D flow simulationGeochemistryGeomechanics
Eclipse
3D Geological model3D Property model of the Reservoir and the Overburden
Zooming in on the sub-surface
The Need for Technology: Hi-Res versus Conventional
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Storage Lifecycle And where is CO2 storage readiness
DevelopmentDevelopmentCO2 InjectionCO2 Injection
ClosureClosure
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Pre SelectionPre Selection
AppraisalAppraisal
Post closurePost closure
Post liability transferPost liability transfer
Performance Management & Risk Control
Performance Management & Risk Control
Pre-injection Injection Post-injection
Designing a monitoring plan
Minimize Costs:
For each technique, For the overall plan over time
Reduce Risk & Optimize Performance:
Added value for the operator
Abide by laws & Regulations:
EU CCS, EU ETS, state law
Site & technicalconstraints:
Deployment restrictions,Measurement sensitivity
Monitoring Plan
Performance & Risk Analysis for CO2 Storage
Measurements (characterization)
• Seismic• Data wells
Measurements (Monitoring)
• CO2 injection• CO2 location
• Sensor selection and specification• Sensor response prediction
Models
• Structure• 3D static
• Monitoring sensor placement
• Storage integrity
• Measurement interpretation• Model update
Performance & Risk Assessment
• Injection efficiency • CO2 in place• Leakage scenarios & rates• Risk ranking
• CO2 migration• Cap rock failure • Well materials degradation
• Dynamic
Intervention,Remediation
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Reducing Uncertainty & Risk over time
Certification at start
Injection start
Characterisation
Site Design & Monitoring Strategy
Uncertainty & Risk
Simulation
Uncertainty & Risk Intervention & Remediation
TimeTransfer of liabilities
Monitoring Simulation
Remediation
Injection stop
Monitoring challenges
Range of scales● Time - from the very short to the very long● Space - from the very small to the very large
You can’t directly measure what you want to…● Spatial distribution and concentration of CO2
● Sealing boundaries capacity permeability● Sealing boundaries, capacity, permeability.
You can’t measure where you want to…● Confined to the surface or wells
…BUT you measure what you CAN and construct models● Consistent with available information● Improve with time● With some predictive power (within limits)
Questions for Designing a Monitoring System
● What do I want to monitor?● What property change can I monitor?● What variation am I considering?
● What measurement technique to use?● What should be my sensor
ifi i ?
● CO2 movements, leaks…● P, CO2 Saturation, Resistivity
● Accuracy / Precisionspecifications?
● Where should I place my sensor?● For how long?● How can I deploy it?● How can I interrogate it?
● How can I interpret the measurement?
● Surface, Obs. Well ● (Permanent, Logging…)
● Operation phase, surveillance
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CO2 Monitoring
monitoring wellAssurance Monitoring (Environment and HSE environment)
Operational Monitoring
injection wellmonitoring well abandoned well
spill pointopen fracture
fractured cap rock leaking
well
freshwater aquifer
Spill pointsSpill points
ContainmentContainmentWell IntegrityWell Integrity
Old wellMonitoringwell
Monitoringwell
Injectionwell
Freshwateraquifer
Sealed faultSealed fault
Tracking the CO2 plume
Verification Monitoring(Watch possible leakage paths)
g
Integrated CO2 Storage Monitoring Programme
Geophysical techniques: Seismic, VSP’s, EM techniques, MicroseismicsLogging: Saturation (Resistivity, Sigma), Well integrity (Casing corrosion, cement bond)Sampling: Pressure, Fluid properties, CO2 concentrationPermanent sensors: Pressure, Temperature
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100
1000
10000
utio
n, m
Tracking CO2 evolution – what we can see
CSEM(Offshore only) Gravity
(Onshore only)
InSAR
Size = relative cost
0.001
0.01
0.1
1
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Verti
cal R
esol
u
Areal Reservoir Coverage
In-wellmeasurements
4D Seismic
Surface-to-wellmeasurements
Well-to-well(Seismic, EM)
Microseismic(Onshore)
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What we can monitor?
CO2 Saturation (neutron, density, resistivity, sonic)Sampling, downhole fluid analysisCased Hole Formation ResistivityPressure & Temperature
2D, 3D SeismicMicroseismicGravimetry (to back up time-lapse seismic)Echosounding, Seafloor samples
In boreholes From the surface
Pressure & TemperatureWell Integrity (Cement, Corrosion)Electrical resistivity tomography (ERT)MicroseismicX-well seismicX-well EMDistributed Temperature SensingTiltmeters
Echosounding, Seafloor samplesNoble Gas TracersMT (natural source plane wave electrical method)CSEMInSAR (Satellite Radar Imaging)
CO2 Saturation Measurement - Ketzin
CO2 Saturation ~ 60% in
Contrast between formation water and CO2 properties can be detected by neutron capture cross-section, hydrogen index, density, resistivity and sonic velocity to quantify the amount of free-phase CO2 present in the pore volume.
2 %upper sand section (yellow).Little presence of CO2 in lower sandNo CO2 above 625 m
625 m
CO2 presence over 4 week interval
Site feasibility
• Are there any wells on the potential storage site?• Do we have access to the well data?• If yes, can we assess the current state of the wells?
Site appraisal
• What data do we need to acquire to assess/reduce the risk of leakage from wells?
• What data do we need to satisfy regulatory requirements
Well integrity risk: questions…
EU regulations state that risk of leakage from apotential storage site must be assessed before astorage licence can be granted.
During operations, risk assessment drives sitemonitoring, post-closure and liability transfer plans.
Concept selection
• Can we convert existing wells to CO2 injectors? • Does any well pose a risk of leakage during project life?• If yes, how could the risk be managed/eliminated?
FDP
• What is the residual risk of leakage from the wells?• What remediation/contingency plans need to be in place during operations life?
• What monitoring plans will be implemented during injection?
Pitting Corrosion
Cement Alteration
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Wellbore Integrity
Acoustic: imaging
Isolation Scanner of the formation wall through casing and cement reveals hole enlargement
Mechanical: multi-finger
caliper
Electromagnetic technology - Local applicationCross-well Electro-Magnetic
A primary electromagnetic field is generated from a first well, inducing currents in the formation and a secondary EM field, detected by receivers in the second well.It has a limited resolution but could be used to track the CO2 plume, possibly in conjunction with seismic methods.
Remote sensing technology - InSAR
Ground deformation monitoring using radar imaging by satellite.
We can calculate the expected changes in surface elevation based on pressure changes and a 1D Mechanical Earth Model.
This allows us to decide if a satellite acquisition will provide the required resolution (several mm).
From Mathieson et al. GHGT9; 2008
Interferometric synthetic aperture radar is a space borne geodetic tool used to obtain high spatial
resolution surface deformation maps.
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Global measurements
Time-lapse Seismic GravimetrySensitive to formation density
CO2 replacing water can be detected due to contrast between CO2 and waterGravimeters are placed at the surface or downhole
Sleipner 4D: Courtesy of Statoil
InSARElevations determined from Synthetic Aperture Radar (SAR) images by interferometric methods.Uses two (microwave) antennas, displaced either vertically or horizontally, installed on the same satellite or aircraft platform.One of the antennas transmits the signal, but both receive it, resulting in two images being created.
Magnetotelluric (MT)Measures the natural low-frequency electromagnetic field of the Earth
AssuranceMonitoring
• Potable water quality• Soils acidity• Atmospheric concentration• Surface deformation
Impact: HSE monitoringInjection operation control• Wellhead pressure• Bottom hole Pressure
and Temperature• Injection rate• Microseismicity
Well Integrity• Annulus pressure• Corrosion• Cement• Soil gas measurements
VerificationMonitoring
OperationalMonitoring
VerificationMonitoring
OperationalMonitoring
Objectives of the monitoring plan - Summary
Tracking the CO2 plume
• Geophysics techniques • Pressure, Temperature• Well logs (CO2 Saturation)• Sampling• Geodetic methods
Quantification of leaks
• Soil gas measurements• Surface gas measurements• …
c ose s c ty
Quantification of injected CO2
• Mass flow• Gas stream composition
and phase
Cap Rock / Fault Integrity
• Microseismicity• Pressure interference
Detection of leaks/migration • Sampling & chemical analysis• Geophysics techniques• Pressure interference• Soil gas measurements• Vegetation stress• Eddy correlation tower
Conclusion: Monitoring as part of Minimizing Storage Risk
Containment – THE storage issue:● Failure of sealing cap rock● Permeable faults and fractures● Migration along wellbores
Risk reduction through:
CapacityCapacity
InjectivityInjectivity
ContainmentContainment● Choosing the right site● Detailed reservoir characterization● Comprehensive modelling● Ongoing monitoring
Risk mitigation through:● Remediation methodologies● Risk-based approach to project
management
Monitoring:● Different types of monitoring objectives● Existing technologies and tools● More work/research on the integration● Closely related to Modelling