Earth Science Division E RNEST O RLANDO L AWRENCE B ERKELEY N ATIONAL L ABORATORY B ERKELEY L AB...

Earth Science DivisionERNEST ORLANDO LAWRENCEBERKELEY NATIONAL LABORATORYBERKELEY LAB 9/30/03

G. Michael HoverstenG. Michael Hoversten

Sally BensonSally Benson

Erika GasperikovaErika Gasperikova

Lawrence Berkeley National LaboratoryLawrence Berkeley National Laboratory

Monitoring ProtocolsMonitoring Protocols


IntroductionIntroduction• Sequestration examplesSequestration examples

– SleipnerSleipner– Numerical simulationNumerical simulation

• Project phases and monitoringProject phases and monitoring• Key Monitoring elementsKey Monitoring elements

– Remote sensingRemote sensing– Surface measurementsSurface measurements– GeophysicsGeophysics

• Monitoring Purpose & methodsMonitoring Purpose & methods• ConclusionsConclusions


Sleipner (North Sea)Sleipner (North Sea)

• COCO22 moves vertically by buoyancy forces moves vertically by buoyancy forces– 100m in 5 years at Sleipner (probably within 1 year)100m in 5 years at Sleipner (probably within 1 year)

• Below ~ 800 m COBelow ~ 800 m CO22 is liquid state is liquid state– Density ~ 20% less than brineDensity ~ 20% less than brine

• Above ~ 800 m COAbove ~ 800 m CO22 is in gas state is in gas state– Density ~ 99% less than brineDensity ~ 99% less than brine

• Critical FactorsCritical Factors– Pressure Pressure

gradientgradient– PermeabilityPermeability– Residual gas Residual gas

saturationsaturation– Density contrastDensity contrast


Numerical SimulationNumerical Simulation

• Residual gas saturation is a factor controlling transport Residual gas saturation is a factor controlling transport – This expresses how much COThis expresses how much CO22 stays behind in the pore space as fluid stays behind in the pore space as fluid

movement occurs movement occurs

• COCO22 Dissolves into brine Dissolves into brine– On 1000On 1000ss year time scale CO year time scale CO22 rich water sinks due to increased density rich water sinks due to increased density


Project Phases & MonitoringProject Phases & Monitoring• Pre-operationPre-operation

– Characterization of the reservoirCharacterization of the reservoir– All background levels of COAll background levels of CO22

• Air, water, soilAir, water, soil

• OperationsOperations– Most vigorous monitoringMost vigorous monitoring

• Reservoir & seal performance Reservoir & seal performance

• ClosureClosure– Surface facilities removed, wells pluggedSurface facilities removed, wells plugged– Confirmatory period to demonstrate that the storage project is Confirmatory period to demonstrate that the storage project is

performing as expected performing as expected

• Post ClosurePost Closure– Monitoring ends except forMonitoring ends except for

• On-going low level leakageOn-going low level leakage• If new information is needed or legal disputesIf new information is needed or legal disputes


Project Phases & MonitoringProject Phases & Monitoring


Key Monitoring elementsKey Monitoring elements• Airborne monitoringAirborne monitoring

– LIDAR (light detection and range-finding) a LIDAR (light detection and range-finding) a scanning airborne laser, and DIAL (differential scanning airborne laser, and DIAL (differential absorption LIDAR) absorption LIDAR)

– Hyper-spectral imagingHyper-spectral imaging• Specific habitats can be identified by their spectral Specific habitats can be identified by their spectral

signature signature • COCO22 stress on vegetation shows up as changes in stress on vegetation shows up as changes in

plants reflectivity at certain wavelengthsplants reflectivity at certain wavelengths

• Surface Detection & QuantificationSurface Detection & Quantification– Infrared gas analyzers (IRGA)Infrared gas analyzers (IRGA)

• Well headsWell heads• Basements & depressionsBasements & depressions

– Soil samplingSoil sampling

• Geochemical MonitoringGeochemical Monitoring– Impact to ground water (analyzed for major ions)Impact to ground water (analyzed for major ions)– Chemical tracers (interaction with the reservoir)Chemical tracers (interaction with the reservoir)

Image after Pickles 2003


Key Monitoring elementsKey Monitoring elements• Well head injection rate & pressureWell head injection rate & pressure

– Over pressuring the reservoir can lead to hydraulic fracturingOver pressuring the reservoir can lead to hydraulic fracturing• Loss of seal integrityLoss of seal integrity• Well failureWell failure

• Geophysical DetectionGeophysical Detection– Mapping spatial changes as injection proceedsMapping spatial changes as injection proceeds– Anomalous event indicator Anomalous event indicator

• LeaksLeaks• Unforeseen transport paths within formationUnforeseen transport paths within formation

• Geophysical QuantificationGeophysical Quantification– How much COHow much CO22 is present at a given location is present at a given location

• Process control to optimize SProcess control to optimize SCO2CO2 • How accurate are flow model predictions?How accurate are flow model predictions?

– Dependent on many more assumptions and knowledge than Dependent on many more assumptions and knowledge than detection for successdetection for success


Key Monitoring elementsKey Monitoring elements

• LeaksLeaks– Seismic is the best way to see Seismic is the best way to see

leaking COleaking CO22 EARLY EARLY

• Large velocity change with Large velocity change with small % COsmall % CO2 2 above ~ 1200mabove ~ 1200m

• Very thin (5m) accumulations Very thin (5m) accumulations will show up on a seismic will show up on a seismic sectionsection

– Assumption: the COAssumption: the CO22 will will

move out laterally at some move out laterally at some point on its upward migrationpoint on its upward migration

• Vertical COVertical CO22 zones are much zones are much

harder to seeharder to see


Monitoring Purpose & MethodsMonitoring Purpose & Methods


Later project ProtocolsLater project Protocols

• Well head sensorsWell head sensors• Airborne imageryAirborne imagery• Periodic water well samplingPeriodic water well sampling• Subsurface Detection onlySubsurface Detection only

– Seismic at 1 yearSeismic at 1 year– Micro-seismicity for 1 or 2 yearsMicro-seismicity for 1 or 2 years

• Continuation depends on activityContinuation depends on activity– Seismic every 5 years for leak detectionSeismic every 5 years for leak detection– Gravity & possible EM every few yearsGravity & possible EM every few years

• Lower cost & resolution Lower cost & resolution – Surface Deformation Surface Deformation

• Permanent Scatter Technique (enhanced In-SAR)Permanent Scatter Technique (enhanced In-SAR)– $100 / raw data $100 / raw data – mm resolutionmm resolution


ConclusionsConclusions• Early projects will be test bedsEarly projects will be test beds• Monitoring Protocols will have to be site specificMonitoring Protocols will have to be site specific

– Site characterization is critical for proper designSite characterization is critical for proper design

• Research is ongoing into sensitivity levels and Research is ongoing into sensitivity levels and improvements of all monitoring systemsimprovements of all monitoring systems

• Subsurface geophysics will dominate costsSubsurface geophysics will dominate costs– Seismic is highest cost, highest resolution, best early Seismic is highest cost, highest resolution, best early

warning of leak in time to prevent COwarning of leak in time to prevent CO22 reaching the surface reaching the surface

• Subsurface monitoring with petroleum heritage is the Subsurface monitoring with petroleum heritage is the most developedmost developed

Earth Science Division E RNEST O RLANDO L AWRENCE B ERKELEY N ATIONAL L ABORATORY B ERKELEY L AB...

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