Prepared for the CCS-CDM working group meeting,Vienna, 7th August 2006 by Mark Raistrick, Applied Geochemistry Group, University of Calgary

Permanence and detection of physical seepageaddressing CDM - Meth panel monitoring concerns

Increasing confidence in fluid and gas monitoring, examples from the IEA Weyburn Project

and other CO2 storage projects.

Structure

The use of chemical and isotopic data

CDM-Meth panel monitoring concerns

Background; fluid and gas monitoring

Examples: 1. addressing permanence 2. physical seepage

Summary and solutions

Source of the atmospheric CO2 increase from1850 - 2000;

carbon isotopes and chemical data

Chemical data: concentration increase;

280ppm to 360ppm since 1850s

Sceptics suggested a ‘natural’ source e.g. volcanism

Carbon isotope values show that the source is most likely to be fossil fuels;

1850s 13C/12C = -7‰2000 13C/12C = -8 ‰ fossil fuels; ~ -20 ‰, volcanic; ~ +2 ‰

CDM - Meth panel monitoring concerns

early state of monitoring science verifying permanence flexibility of monitoring techniques effectiveness of leakage detection abrupt emissions monitoring that a DOE can verify

Fluid and Gas monitoring

Background:

Data from full scale project; one million tonnes/year of CO2 injection for 5 years, and a smaller pilot project Scientific methods that have been used for decades e.g. aquifer contamination, acid gas injection. Weyburn study is with the leading environmental engineering journal.

Two examples using chemical and isotopic data fromfluid and gas monitoring:

1. to verify storage of large volumes of CO2 (permanence)

2. to detect small volumes of CO2 (leakage)

Principles; what happens to CO2 injectedinto aquifers and oilfields?

Short term trapping mechanisms(after Gunter et al. 1997, 2000, 2004)

a) trapping of molecular CO2 inhydrocarbon and aqueous fluids

b) Ionic trapping of dissolved and dissociated CO2as bicarbonate (HCO3

-)

ionic trapping; CO2(gas) + H2O ⇔ H+ + HCO3-

The quantity of CO2 stored as HCO3- is directly related

to the amount of molecular CO2 dissolved in the reservoir.

1. Using fluid and gas monitoring toverify storage at the IEA Weyburn Project

Background:Baseline and regular monitoring of produced fluidsand gases during injection period. Samples collectedat wellhead (45 wells).

Baseline survey fluid data:

HCO3- concentration at baseline

= 250mg/litre

HCO3- carbon isotope values (δ13C):

δ13CHCO3- at baseline ~ -3‰

δ13CHCO3- from injected CO2 = -16‰

HCO3- (mg/L)HCO3

- (mg/L)

HCO3- (mg/L) HCO3

- (mg/L)

Storage at Weyburn; carbon isotopes confirm the HCO3-

source, while HCO3- concentration increase quantifies

ionic trapping of injected CO2

Permanence of storage at Weyburn

After five years and five million tonnes of CO2injection at Weyburn:

In the vicinity of the sampling wells 1000mg/litre ofinjected CO2 is stored as HCO3

- by ionic trapping.

(CO2(aq) + H2O ⇔ H+ + HCO3-)

HCO3- concentration is sensitive to amount of

molecular CO2 dissolved in the brines and thereforethe integrity of storage.

2. Physical seepage; using gas monitoringto detect small amounts of injected CO2

BackgroundA CO2 storage/EOR pilot with an injection rate of <1000 tonnes permonth. Monitoring wells 100m and 400m from injectors.

Chemical analysisof gases detects CO2arrival; is this theinjected CO2?

Physical seepage; using gas monitoring todetect small amounts of injected CO2

Carbon isotopemeasurementsof CO2 (δ13C )identify CO2source

Injected CO2 detected at monitoring wells within one month of injection beginning. The data demonstrate that gas measurements can detect small amounts of migrating CO2.

Summary; fluid and gas monitoring forpermanence and physical seepage

Fluid chemical and isotopic measurements quantify ionic trapping; the mass of injected

CO2 stored as HCO3-, and provide proxy for

mass stored as molecular CO2.

Gas chemical and isotopic measurements allowdetection of small amounts of injected CO2.

Costs; sample collection and chemical and isotopic analysis around C$1000-2000 (750-1500 Euros)per sample per well.

Requires baseline survey and monitoring wells.

Solutions; fluid and gas monitoring forpermanence and physical seepage

Integration of monitoring with modeling; usereservoir and regional models to plan monitoring strategy, and use monitoring data to validatemodels; modify injection and monitoring as

necessary

Integration of fluid and gas and geophysical monitoring; match fluid and gas data withseismic images of CO2 plume for carbonaccounting. Use multi zone wells.

Regular monitoring after site closure to ensure post crediting period storage permanence

CDM - Meth panel monitoring concerns

early state of science verifying permanence flexibility of monitoring techniques effectiveness of leakage detection abrupt emissions monitoring that a DOE can verify

CDM - Meth panel monitoring concerns

early state of science verifying permanence flexibility of monitoring techniques effectiveness of leakage detection abrupt emissions monitoring that a DOE can verify

CDM - Meth panel monitoring concerns

early state of science verifying permanence flexibility of monitoring techniques effectiveness of leakage detection abrupt emissions monitoring that a DOE can verify

CDM - Meth panel monitoring concerns

early state of science verifying permanence flexibility of monitoring techniques effectiveness of leakage detection abrupt emissions monitoring that a DOE can verify

CDM - Meth panel monitoring concerns

early state of science verifying permanence flexibility of monitoring techniques effectiveness of leakage detection? abrupt emissions? monitoring that a DOE can verify

? = for discussion

Fluid and gas monitoring;concluding remarks

Will these chemical and isotopic techniques work everywhere? Industrial CO2 sources are distinct from CO2 and HCO3

- found in the vast majority of oil and gas reservoirs and deep saline aquifers.

Integration is the key; good site selection, reservoir and regional models, combined with a range of monitoring techniques.

Co-authors from the University of Calgaryand Alberta Research Council

Bernhard Mayer, Maurice Shevalier,Renee Perez, Michael Nightingale and Ian Hutcheon Applied Geochemistry Group, Department of Geology and Geophysics, University of Calgary, Calgary, Alberta, Canada

Ernie Perkins and Bill GunterAlberta Research Council, Edmonton, Alberta, Canada

Support from PTRC and the government and industry sponsors of the IEA Weyburn Project.

NM0167 White Tiger - likely that power plant flue gas is distinct fromHCO3- in reservoir brines eq with igneous resrv rock.it would work in Sleipner (~ -5ppmil) if Utsira is lighter (-10)technogenic. fm CO2 in the Viking Graben and Norwegian Shelf >-12ppmil near surface~ 1km, carbonate like -3ppmil at 3km depth).Some WCSB reservoirs with no primary carbonate (secondarycarbonate has been shown to preserve organic carbon -like carbonisotope ratios, and extensive bacterial (or thermal) oxidation ofhydrocarbons will evolve inudstial-like d13C for formation CO2 - inthese reservoirs the injected and formaiion carbon isotopes will besimilar and this technique will be less useful. Aquifers with littleorganic carbon will likely have heavier CO2 derived from primarycarbonate minerals.Throughout the Alberta Basin +2 to -8 delta values for carbonates, vlow d13C CO2 values at depth with TSR,Miller -8 for formation CO2. Lena field Louisiana -10ppmil.Krouse et al. 1988; Leduc -10, Turner valley =0 for CO2

Data suggests that most reservoir CO2 is mix of inorg. and orgsources and therefore between+5 and -15, most industrial CO2 is fromorg C and is less than -20.

Table d13C CO2 (atmos smallest reservoir ~ -6.4, and decreasing,mantle -8/industrial -25 /thermal deg./BSR/carbonate dssn 0 ish,thermal and bacterial methane deg/decarboxylation)(TABLE? NM0167

White Tiger capture from flue, reinject forEOR/storage in

igneous reservoir! Formation d13C = ?NM0168 LNG Malaysia capture form nat gas inject inaquifer - d13C depends on gas origin, aquifer targetlikely carbonate - like)

Introduction to using chemical and isotopicdata; a familiar example

Chemical and isotope data and an anthropogenic source for the last 200 years of carbon dioxide Concentration increase;

280 to 360ppm since 1800s

Sceptics suggested a ‘natural’ source e.g. volcanism

Carbon isotope values show that the source is most likely to be fossil fuels;

1800s 13C/12C = 2000 13C/12C =