Organic and Inorganic Pore Structure Analysis in Shale Rocks with Superposition Method

1. Organic and Inorganic Pore Structure Analysis in Shale Rocks with Superposition Method Dr. Chenchen Wang Prof. Zhangxing (John) Chen University of Calgary 06/14/2014

2. Outline Introduction 1 2 Methodology Results and Discussions 3 Conclusions 4 Future Research 5

3. 1. Introduction Shale rocks are inherently heterogeneous and the shale matrix pores can be divided into organic and inorganic pores. The organic and inorganic pores are distributed with each other in the shale matrix. Organic matter: 3%-15% (Organic pores + few inorganic pores) Shale matrix Inorganic matter (Inorganic pores) Typical shale matrix SEM image with organic and inorganic pores

4. 1. Introduction Different Scale Resolution Images Digital Rock Analysis Technology While the organic pores and inorganic pores in shale rocks are at different scales, and the transport mechanisms of shale gas in organic and inorganic pores are different, it is necessary to describe the nanoscopic organic and inorganic pore characteristics of shale rocks with a method, such as superposition, based on a digital rock analysis technology.

5. Outline Introduction 1 2 Methodology Results and Discussions 3 Conclusions 4 Future Research 5

6. 2. Methodology 2.1 Image analysis and 3D digital rock reconstruction SEM images Low resolution inorganic pore image High resolution organic pore image Resolution: 25nm Resolution: 5nm Binary images 0: skeleton (white) 1: pore (black) Organic pore binary image Inorganic pore binary image

7. 2. Methodology 2.1 Image analysis and 3D digital rock reconstruction xy Markov Chain Monte Carlo (MCMC) Method yz xz Organic pore digital rock 500×500×500 Inorganic pore digital rock 216×216×216

8. 2. Methodology 2.2 Shale matrix digital rock superposition method Step 1. Superposition of representative shale organic matter digital rocks The sectional inorganic pore digital rock 100×100×100 The sectional inorganic pore digital rock 500×500×500 Inorganic pore digital rock 216×216×216 Superposition algorithm: Ω: shale organic matter digital rock Ω1: inorganic pore digital rock Ω2: organic pore digital rock

9. 2. Methodology 2.2 Shale matrix digital rock superposition method Step 1. Superposition of representative shale organic matter digital rocks Representative shale organic matter digital rock 500×500×500 The sectional inorganic pore digital rock 500×500×500 Organic pore digital rock 500×500×500

10. 2. Methodology 2.2 Shale matrix digital rock superposition method Step 2. Integration of representative shale matrix digital rocks The remaining inorganic pore digital rock Representative shale matrix digital rock Representative shale organic matter digital rock

11. Outline Introduction 1 2 Methodology Results and Discussions 3 Conclusions 4 Future Research 5

12. 3. Results and Discussions Organic pore digital rock Representative shale matrix digital rock Inorganic pore digital rock

13. 3. Results and Discussions

14. 3. Results and Discussions Pore size volume distribution Pore size distribution The representative shale matrix digital rock with the superposition method has a bimodal pore volume distribution; the first mode reflects the inorganic pores with relatively larger pore sizes, while the second mode reflects the organic pores with relatively smaller pore sizes.

15. 3. Results and Discussions

16. Outline Introduction 1 2 Methodology Results and Discussions 3 Conclusions 4 Future Research 5

17. 4. Conclusions (1) A two-step superposition method is introduced to construct the representative shale matrix digital rock, and a comparison of the pore structure properties among the three digital rocks shows that the superposition shale matrix digital rock can characterize the inorganic pore and organic pore properties simultaneously. (2) This method provides a research platform for the study of different pore structure characteristics in shale rocks, and it can also be used as input for the nanoscopic flow simulation in pores with different wettability.

18. Outline Introduction 1 2 Methodology Results and Discussions 3 Conclusions 4 Future Research 5

19. 5. Future Research 5.1 Wettability Analysis Organic Pore: Oil-wet Inorganic Pore: Water-wet

20. 5. Future Research 5.2 Fracture Description Regular Fracture-Digital Rock Orientation Aperture Number Occurrence Dip

21. 5. Future Research 5.2 Fracture Description Regular Fracture-Pore Network

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