Post on 30-Dec-2015
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Monitoring Geologic Sequestration: Transition from Demonstration to Commercial Environments: Questions for
Discussion Susan Hovorka
Gulf Coast Carbon CenterBureau of Economic Geology
Jackson School of GeosciencesThe University of Texas at Austin
Presented to RWG of SECARBJanuary 31, 2007
Monitoring Options• Atmosphere
– Ultimate receptor but dynamic• Biosphere
– Assurance of no damage but dynamic
• Soil and Vadose Zone– Integrator but dynamic
• Aquifer and USDW– Integrator, slightly isolated from
ecological effects• Above injection monitoring zone
– First indicator, monitor small signals, stable.
• In injection zone - plume– Oil-field type technologies. Will not
identify small leaks• In injection zone - outside plume
– Assure lateral migration of CO2 and brine is acceptable
Aquifer and USDW
Atmosphere
Biosphere
Vadose zone & soil
Seal
Seal
CO2 plume
Monitoring Zone
A balanced and phased approach to permitting and monitoring
Not too restrictive: encourage early entry into CCS – gain experience;
Learn by doing
Adequate rigor to assure
that early programs do not fail
Standardized, parsimonious
Early (now)
Mature (As defined by time? Or byinjection volume?)
Adequately rigorousto assure performanceand public acceptance
Phased Balanced
The Question of Balance: How Much is Enough?
4-D seismic
MonitoringMitigation/Corrective
Action
PublicParticipation
Less
M
ore
3-D seismic
Multiple in-zone wells
Regional +injection well
Test program
Site Characterization
Multiple zonesmultiple tools
MITsurface pressureinjected volumes
Selected toolsSelected zones
Redundantinjection sites/
pipeline system
Response ifnon-compliance
occurs
Stop injection
Litigation
Public comment& responsemechanisms
Public hearings
Public information
Examples, not an exhaustive list
Phased Approach
• Brine aquifer demonstrations and experiments in are class 5; EOR demonstrations and experiments are class 2
• What is the distinction between demonstrations and experiments and commercial projects?– Timing?– Injection volume?– Approach e.g. research goal?– How does a well convert from a demonstration to commercial?
• Relevance to FutureGen and DOE NETL RCSP Phase III projects as well as various projects in planning.
• How are mature commercial CO2 injection wells permitted?– Work underway by EPA, IOGCC, partnerships, national labs
The Question of Balance: How Much is Enough?
4-D seismic
MonitoringMitigation/Corrective
Action
PublicParticipation
Less
M
ore
3-D seismic
Multiple in-zone wells
Regional +injection well
Test program
Site Characterization
Multiple zonesmultiple tools
MITsurface pressureinjected volumes
Selected toolsselected zones
Redundantinjection sites/
pipeline system
Response ifnon-compliance
occurs
Stop injection
Litigation
Public comment& responsemechanisms
Public hearings
Public information
Texas Class I
Texas FutureGen
Change in risk with volume of injection
• Footprint of the plume and cone of higher pressure becomes larger as volume increases, and will change with time as injection continues.
• Large plume and large increased pressure increase risk of encountering a flawed seal or creating an unacceptably large brine displacement.
• Stacking injection in multiple zones or thicker injection interval will reduce footprint and impact of displaced brine
CO2 plumeElevated pressure
Monitoring Options• Atmosphere
– Ultimate receptor but dynamic• Biosphere
– Assurance of no damage but dynamic
• Soil and Vadose Zone– Integrator but dynamic
• Aquifer and USDW– Integrator, slightly isolated from
ecological effects• Above injection monitoring zone
– First indicator, monitor small signals, stable.
• In injection zone - plume– Oil-field type technologies. Will not
identify small leaks• In injection zone - outside plume
– Assure lateral migration of CO2 and brine is acceptable
Aquifer and USDW
Atmosphere
Biosphere
Vadose zone & soil
Seal
Seal
CO2 plume
Monitoring Zone
Frio 1 Pilot: Cross-Comparison of Multiple Types of Measurements
Downhole P&T
Radial VSPCross well Seismic, EM
Downhole samplingU-tubeGas lift
Wirelinelogging
Aquifer wells (4)Gas wells Access tubes, gas sampling
Tracers
Determine the subsurface distribution of injected CO2 using diverse monitoring technologies
Frio 2 Monitoring Design:Test of buoyancy, residual saturation, dissolution
Injection Well Observation Well
50 m
U-tubes
RST logs
Frio “Blue”
Sandstone
15m thick
PackersDownhole P and T
Tubing-hung seismic source
and hydrophones
Injectionwell
Otway Pilot (Australia) Time Structure Map
From Sandeep Sharma, OBPP, CO2CRC
Otway Pilot (Australia) Key Monitoring Objectives
• Confirm conduct all tasks safely and to the satisfaction of all stakeholders.
Assurance Monitoring (no leakage)
• Soil and atmospheric measurements to confirm non leakage/seepage of injected Co2.
• Hydrogeological monitoring to ensure no leakage of CO2 into the overlying aquifers
Storage Integrity Monitoring (predicted behaviour)
• Monitor the injected CO2 plume to :
– Validate migration paths - geophysics
– Validate migration times - geochemistry
– Validate likely shape - reservoir properties
– Validate geomechanical integrity - dynamic behaviour
From Sandeep Sharma, OBPP, CO2CRC
Otway Monitoring Technology Options • Data acquisition programs and frequency of time-lapse measurements
– Implications and tradeoffs vs completion design
– Prioritization of relative importance of each measurement to ease decision making
Objective Criticality SurfaceSeismic & VSP
micro
Seismic
Water Wells
Atmospheric
Soil Gas
U tube
RST SFRT Integrity Logs
Breakthrough detection
Plume shape
Plume travel path
Plume travel speed
Containment
CO2 area of accumulation
Public Acceptance
From Sandeep Sharma, OBPP, CO2CRC
Otway Pilot (Australia) Soil Gas Sampling Monitor gas compositions in the soil to order to measure any near surface change in CO2 composition or concentration
-25
-20
-15
-10
-5
100 1000 10000 100000CO2 ppm (vol)
13C
CO
2 (
o/ o
o)
Otway Pilot area
Cape Grim air 2001
Otway air 2005
Airbackground
organic matter 'decomposition'
deep subsurface
Otway natural gasrange
average
From Sandeep Sharma, OBPP, CO2CRC
Otway Pilot (Australia) Atmospheric MonitoringMonitor CO2 in the atmosphere and define the sources
Flux Tower Lo-Flo*
From Sandeep Sharma, OBPP, CO2CRC
Monitoring Schemes: Monitoring in Mature Context
• Benson study showing that cost of a monitoring scheme, basic or enhanced, is a small fraction of the cost of the whole project.
• Should a large injection then have a large monitoring program?
Techniques to Assure Safe Injection of CO2 Used Currently
• Health and safety procedures for CO2 pipelines, shipping, handling, and storing
• Pre-injection characterization and modeling• Isolation of injectate from Underground Sources of Drinking Water
(USDW) via characterization• Maximum allowable surface injection pressure (MASIP) to prevent
fractures and earthquakes.• Mechanical integrity testing (MIT) of engineered system to prevent
well leakage• Standards for well completion and plug and abandonment in cone
of influence and area of review around injection wells.• Reservoir management; extensive experience in modeling and
measuring location of fluids
Need for Parsimonious Monitoring Program in a Mature Industry
• Standardized, dependable, durable instrumentation, reportable measurements
• Possibility of above-background detection:– Need for a follow-up testing program to assure both
public acceptance and safe operation• Hierarchical approach:
Parameter A
Within acceptable limits:continue
Parameter BNot withinacceptable limits:test
Within acceptable limits:continue
Stop & mitigateNot withinacceptable limits:
Conclusions
• Monitoring approach depends on phase of deployment– Dense monitoring in research phase to
increase confidence– Parsimonious monitoring in commercial phase
• Clarification of the effective but parsimonious strategy to be developed in upcoming projects.