Permanence and detection of physical seepage addressing CDM - Meth panel monitoring concerns

Transcription

1 Permanence and detection of physical seepage addressing CDM - Meth panel monitoring concerns Increasing confidence in fluid and gas monitoring, examples from the IEA Weyburn Project and other CO 2 storage projects. Prepared for the CCS-CDM working group meeting, Vienna, 7th August 2006 by Mark Raistrick, Applied Geochemistry Group, University of Calgary

2 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

3 Source of the atmospheric CO 2 increase from ; 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 13 C/ 12 C = C/ 12 C = -8 fossil fuels; ~ -20, volcanic; ~ +2

4 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

5 Background: Fluid and Gas monitoring Data from full scale project; one million tonnes/year of CO 2 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 from fluid and gas monitoring: 1. to verify storage of large volumes of CO 2 (permanence) 2. to detect small volumes of CO 2 (leakage)

6 Principles; what happens to CO 2 injected into aquifers and oilfields? Short term trapping mechanisms (after Gunter et al. 1997, 2000, 2004) a) trapping of molecular CO 2 in hydrocarbon and aqueous fluids b) Ionic trapping of dissolved and dissociated CO 2 as bicarbonate (HCO 3- ) ionic trapping; CO 2(gas) + H 2 O H + + HCO 3 - The quantity of CO 2 stored as HCO 3 - is directly related to the amount of molecular CO 2 dissolved in the reservoir.

7 1. Using fluid and gas monitoring to verify storage at the IEA Weyburn Project Background: Baseline and regular monitoring of produced fluids and gases during injection period. Samples collected at wellhead (45 wells). Baseline survey fluid data: HCO 3 - concentration at baseline = 250mg/litre HCO 3 - carbon isotope values (δ 13 C): δ 13 C HCO3- at baseline ~ -3 δ 13 C HCO3- from injected CO 2 = -16

8 Storage at Weyburn; carbon isotopes confirm the HCO 3 - source, while HCO 3 - concentration increase quantifies ionic trapping of injected CO 2 HCO 3 - (mg/l) HCO 3 - (mg/l) HCO 3 - (mg/l) HCO 3 - (mg/l)

9 Permanence of storage at Weyburn After five years and five million tonnes of CO 2 injection at Weyburn: In the vicinity of the sampling wells 1000mg/litre of injected CO 2 is stored as HCO 3 - by ionic trapping. (CO 2(aq) + H 2 O H + + HCO 3- ) HCO 3 - concentration is sensitive to amount of molecular CO 2 dissolved in the brines and therefore the integrity of storage.

10 2. Physical seepage; using gas monitoring to detect small amounts of injected CO 2 Background A CO 2 storage/eor pilot with an injection rate of <1000 tonnes per month. Monitoring wells 100m and 400m from injectors. Chemical analysis of gases detects CO 2 arrival; is this the injected CO 2?

11 Physical seepage; using gas monitoring to detect small amounts of injected CO 2 Carbon isotope measurements of CO 2 (δ 13 C ) identify CO 2 source Injected CO 2 detected at monitoring wells within one month of injection beginning. The data demonstrate that gas measurements can detect small amounts of migrating CO 2.

12 Summary; fluid and gas monitoring for permanence and physical seepage Fluid chemical and isotopic measurements quantify ionic trapping; the mass of injected CO 2 stored as HCO 3-, and provide proxy for mass stored as molecular CO 2. Gas chemical and isotopic measurements allow detection of small amounts of injected CO 2. Costs; sample collection and chemical and isotopic analysis around C$ ( Euros) per sample per well. Requires baseline survey and monitoring wells.

13 Solutions; fluid and gas monitoring for permanence and physical seepage Integration of monitoring with modeling; use reservoir and regional models to plan monitoring strategy, and use monitoring data to validate models; modify injection and monitoring as necessary Integration of fluid and gas and geophysical monitoring; match fluid and gas data with seismic images of CO 2 plume for carbon accounting. Use multi zone wells. Regular monitoring after site closure to ensure post crediting period storage permanence

14 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

15 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

16 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

17 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

18 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

19 Fluid and gas monitoring; concluding remarks Will these chemical and isotopic techniques work everywhere? Industrial CO 2 sources are distinct from CO 2 and HCO 3 - 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.

20 Co-authors from the University of Calgary and 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 Gunter Alberta Research Council, Edmonton, Alberta, Canada Support from PTRC and the government and industry sponsors of the IEA Weyburn Project.

21

22 NM0167 White Tiger - likely that power plant flue gas is distinct from HCO3- 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 (secondary carbonate has been shown to preserve organic carbon -like carbon isotope ratios, and extensive bacterial (or thermal) oxidation of hydrocarbons will evolve inudstial-like d13c for formation CO2 - in these reservoirs the injected and formaiion carbon isotopes will be similar and this technique will be less useful. Aquifers with little organic carbon will likely have heavier CO2 derived from primary carbonate minerals. Throughout the Alberta Basin +2 to -8 delta values for carbonates, v low 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 org sources and therefore between+5 and -15, most industrial CO2 is from org C and is less than -20. Table d13c CO2 (atmos smallest reservoir ~ -6.4, and decreasing,

23 Introduction to using chemical and isotopic data; 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 13 C/ 12 C = C/ 12 C =