1. Preliminary Results of Pembina Cardium Core Analysis C.R. Clarkson and N. Solano (PhD Candidate) T O C © TOC, 2011

2. Outline 1 Objectives Well Locations Sampling and Measurements CT Scans N 2 Adsorption Analysis Comparison to Bakken and 2WS SANS/USANS Future Work T O C

3. Objectives Select low-permeability oil reservoir samples from the Cardium Formation to perform preliminary laboratory experiments Use X-Ray CT Scans to evaluate changes in rock density and porosity and use to evaluate locations for permeability measurements (+ density of measurements) Use low-pressure adsorption and small-angle neutron scattering (SANS and USANS) to establish pore structure characteristics by facies  To date, only “muddier” intervals have been studied Establish controls on pore structure variation Establish relationship between pore structure and permeability 2

4. Sampling/Measurements CORES SAMPLED / ANALYZED: 1. 08-17-049-06W5, CORE #1, BOXES 3 – 13 2. 08-04-049-06W5, CORE #4, BOXES 5 – 11 3. 04-24-049-07W5, CORE #1, BOX 11; CORE #2, BOXES 1 – 5; CORE #3, BOXES 1 – 4 (FUTURE) MEASUREMENTS (to date): 1. Coreplugs taken from 8-17 and sub-sampled for SANS/USANS (discs prepared) at NIST (1/2011) and ORNL (3/2011) 2. N2 adsorption analysis performed on 8-17 coreplugs for surface area/PSD (8/2011) 3. 8-17 and 8-4 full-diameter cores were “scout” (CT) scanned to identify locations for axial scans (7/2011) 4. Axial (CT) scans performed on 8-17 and 8-4 (8/2011) 5. Pulse-decay permeability measurements performed on 8-17 coreplugs 3

5. 08-17-49-6W5 4-24-49-7W5 8-4-49-6W5 LOCATIONS WITH CORES TO SAMPLE Structure contour map: top of the Cardium SS 4

6. MD (m) CZ Cardium A a b 08-17-049-06W5 Res 5

7. 6 AVAILABLE RCA (Whole core diam.) Kmax, PHI, GRAIN DENSITY SANS/USANS (Horizontal disks 10 mm diameter x 1 mm thick) 3 disks from: 1374.3 m 5 disks from: 1377.0 m INTERVALS TO SAMPLE/ANALYZE CTS: 1364.3 – 1377.8 m SLABBING: 1364.3 – 1377.8 m SAND BLASTING: 1364.3 – 1377.8 m PROBE K: 1364.3 – 1377.8 m XRF: 1364.3 – 1377.8 m CTS 6

8. CT Scans CT Scans: Scout Scans 08-17-049-06W5 Axial scan location 1364.3 m 7

9. Mean porosity= 9.1% Mean porosity= 7.2% Mean porosity= 8.6% Mean porosity= 7.0% Mean porosity= 7.8% Mean porosity= 7.6% Mean porosity= 7.7% Mean porosity= 4.2% Mean porosity= 6.5% 8

10. CT Scans CT Scans: Scout Scans 08-17-049-06W5 Axial scan location 1368.96 m 9

11. 10 Mean porosity= 10.0% Mean porosity= 13.9% Mean porosity= 15.2% Mean porosity= 21.7% Mean porosity= 18.6% Mean porosity= 14.0% Mean porosity= 12.4% Mean porosity= 10.0% Mean porosity= 13.6% 10

12. CT Scans CT Scans: Scout Scans 08-17-049-06W5 Axial scan location 1374.59 m Coreplugs 11

13. 12 Mean porosity= 9.9% Mean porosity= 9.0% Mean porosity= 9.9% Mean porosity= 9.5% Mean porosity= 10.4% Mean porosity= 8.6% Mean porosity= 8.8% Mean porosity= 8.0% Mean porosity= 9.5% 12

14. CT Scans CT Scans: Scout Scans 08-17-049-06W5 Axial scan location 1377.49 m Coreplugs 13

15. 14 Mean porosity= 7.8% Mean porosity= 7.6% Mean porosity= 7.8% Mean porosity= 9.2% Mean porosity= 8.0% Mean porosity= 7.9% Mean porosity= 9.2% Mean porosity= 7.9% Mean porosity= 6.7% 14

16. N 2 Adsorption/Desorption Isotherms Shape: qualitative assessment of pore structure Adsorption/desorption hysteresis: – Type IV isotherms, mesoporous solids (2 nm < d < 50 nm) – Shape of hysteresis loop can be indicative of pore geometry Interpret isotherm data in terms of surface area (ex. BET Theory) and pore size distributions (ex. BJH Theory) 15

17. N 2 Adsorption/Desorption Isotherms Similar amounts of adsorption for all samples except D2 Substantial mesopore volume Hysteresis loops may be indicative of slit-shaped pores 16

18. N 2 Adsorption/Desorption More adsorption in Bakken, less in 2WS Differences in Hysteresis Loop Shape – pore structure differences? 17

19. N 2 Adsorption/Desorption BJH Analysis (PSD) Capillary condensation of vapours in mesoporous materials Uses Kelvin equation to relate vapour pressure to pore size Can use desorption (convention) or adsorption branch (Figure) – Step AB: removal of capillary condensate – Step BC: removal of condensate from cores, multi-layer thinning of emptied (larger) pores From SPE 147397 Desorption analysis using BJH Theory 18

20. N 2 Adsorption/Desorption BJH Analysis (PSD) Primarily unimodal pore size (peak ~ 200 – 350 A, desorption) Artifact at ~ 35 A on desorption curves Small pore size translates into low permeability (later) 19

21. N 2 Adsorption/Desorption Cardium-Bakken, similar pore sizes, but difference in volume 2WS – less mesoporosity 20

22. N 2 Adsorption/Desorption Cardium-Bakken, similar pore sizes, but difference in volume 2WS – less mesoporosity 21

23. N 2 Adsorption/Desorption BJH Analysis (PSD) Effect of degas temperature 22

24. N 2 Adsorption/Desorption BJH Analysis (PSD) Comparison to Montney tight gas reservoir Permeability implications From Clarkson et al. AAPG Bulletin, in press 23

25. N 2 Adsorption/Desorption BET (Surface Area) Extension of Langmuir’s Theory to multilayer adsorption Very common method for surface area analysis From SPE 147397 Desorption analysis using BJH Theory 24

26. N 2 Adsorption/Desorption 25

27. N 2 Adsorption/Desorption Relationship to Permeability Can we relate pore structural parameters to permeability (dominant pore size, BET surface area?) Currently gathering permeability/porosity data for Cardium so plot like the one on the right (Montney TG) can be developed From Clarkson et al. AAPG Bulletin, in press 26

28. SANS/USANS In a SANS experiment, a neutron beam is directed at a sample, and the neutrons are elastically scattered due to their interaction with nuclei of atoms in the sample The scattering vector is related to a characteristic length scale (pore size) in the sample SANS experiments, combined with USANS, also enable a wide distribution of pore sizes (~ 0.3 nm to ~ 10 μm) to be investigated From Melnichenko et al. (2009) 27

29. SANS/USANS Analysis 28

30. SANS/USANS Similar scattering patterns for all except: – B1 and B2 exhibit a “hump” at large Q, maybe related to composition Higher scattering intensity generally translates into higher porosity Slope of linear portion of curves (power-law scattering) is close to -3 For surface fractal geometry (equivalent pore space is uncorrelated spherical pores), slope is -3 to -4 SANS USANS 29

31. SANS/USANS Comparison to Montney tight gas reservoir Montney has greater slopes (-3.1 to -3.3) 30

32. SANS/USANS Fit of 1102A1 to PDSP model using PRINSAS 31

33. SANS/USANS Fit of 1101A2 to PDSP model using PRINSAS 32

34. SANS/USANS 33

35. Future Work Gather profile permeability, XRF and additional pulse- decay permeability data Relate pore structural information to permeability Examine compositional and structural controls on porosity and permeability 34