1. CO 2 Sequestration in Gas Shales of Kentucky Brandon C. Nuttall, James A. Drahovzal, Cortland F. Eble, R. Marc Bustin U.S. DOE/NETL DE-FC26-02NT41442 AAPG Calgary June 19-22, 2005

2. Why Black Shales? Distribution and potential storage volumeDistribution and potential storage volume Known producerKnown producer –Gas adsorbed on kerogen and clay Analogous to CBM?Analogous to CBM?

3. Basic Research: Feasibility CO 2 sorption capacityCO 2 sorption capacity CH 4 displacement potentialCH 4 displacement potential

4. Devonian Shale in Kentucky Estimated gas in place: 63 to 112 tcf Present in subsurface >=1000 deep and >=100 thick Producing area

5. Big Sandy Reservoir Info Completion interval >500Completion interval >500 Average porosity 4.3%Average porosity 4.3% Max. porosity 11%Max. porosity 11% Temperature 84 o FTemperature 84 o F Average pressure 400 psiAverage pressure 400 psi Permeability <0.1 mdPermeability <0.1 md Atlas of Major Appalachian Gas Plays, 1996

6. Typical Reservoir Conditions for CO 2 Injection Critical Point Saturation Line Melting Line Temp (ºF) Pressure (psia) Solid Liquid Gas

7. Geologic Column Surface 1,000 2,000 3,000 4,000 Coal measures, mixed sand, shale, and coal. Salt sands Pennington: Sand and shale Big Lime: Carbonate Pennsylvanian Mississippian Devonian Borden: Sand and shale Ohio: Carbonaceous black shale 3,800 +/- of mixed sand, shale, and carbonate provide adequate reservoir seal. Composite thickness data from Knott and Leslie County wells and Dillman and Ettensohn (1980)

8. Shale Overview Mississippian Borden Cleveland Devonian Ohio Shale Berea Sunbury Three Lick Bed Upper Huron Middle Huron Lower Huron Olentangy 3-component system3-component system –Quartz –Clay –Organic matter 3-component system3-component system –Quartz –Clay –Organic matter } Clastic GR Density

9. Cross section LAS file AdsorptionBoth Study Area

10. Average Organic Content Total Organic Carbon

11. Mean Random Reflectance Upper oil window and wet gas/condensates R 0 random x 1.066 ~ R 0 max Frequency

12. Devonian Shale Adsorption Isotherms Standard cubic feet per ton CO 2 CH 4

13. Adsorption at 400 PSIA Adsorbed gas (standard cubic feet per ton of shale) Average CH 4 : 8.1 scf/ton Average CO 2 : 42.9 scf/ton CO 2 = 5.3 x CH 4 Frequency

14. CO 2 Adsorption at 400 PSIA r 2 = 0.80 CO 2 scf/ton = 7.9 x TOC + 20.7

15. CNR 24752 Elk Horn

16. Cleveland Three Lick Upper Huron Middle Huron Lower Huron Olentangy Sunbury Borden Berea 1 4 1 1 1 2 Sidewall cores for adsorption and CH 4 displacement

17. ECS Shale Analysis Clays BoundWater Kerogen GasSaturation TotalPhi Adsorbed Gas (scf) TotalGas(scf) TOC Cum.Gas(bcf) QFM

18. Crossplot Lower density & Higher GR = More organic RhoB max gray shale = 2.82 g/cc (g/cc)

19. Calculate TOC from RhoB Schmoker, 1993, USGS Bull 1909

20. Shading based on density (RhoB) <2.4 >2.8 More carbonaceous More clastic Cross Section WE 1,600 feet 72 miles

21. 27.6 Billion Tons CO 2 Estimated 40 scf/ton thickness weighted average >3 MM <1 MM Tons/sq km

22. Future Map TOC from density logsMap TOC from density logs New estimate of CO 2 capacityNew estimate of CO 2 capacity Demonstration projectDemonstration project –CO 2 monitoring Surface soils Produced gas –Reservoir simulation

23. Conclusion Preliminary analyses indicate the organic-rich Mississippian– Devonian shales of Kentucky have the potential to sequester large volumes of CO 2. www.uky.edu/kgs