Comparative analysis of shale pore size characterization methods

Abstract

The pore size distribution of four shale samples were characterized by and compared between CO₂ adsorption, N₂ adsorption, MIP and NMR. The results show that CO₂ adsorption has an absolute advantage for characterization of pores smaller than 2 nm. N₂ adsorption is reliable for 2–50 nm pore characterization and is superior to NMR in the 2–10 nm range. NMR has advantages for 10–100 nm pore characterization, and MIP has advantages for characterization of pores larger than 100 nm. NMR offers the widest range of observations, and order of the maximum resolution of these methods is CO₂ adsorption > N₂ adsorption > NMR > MIP.

Keywords:

• gas adsorption
• high-pressure mercury intrusion
• nuclear magnetic resonance
• pore size distribution
• shale pore

Acknowledgments

We would like to thank anonymous reviewers for their suggestions.

Additional information

Funding

This study received support from Ministry of Science and Technology of the People’s Republic of China (Grant No. 2016ZX05034).