Skip to main content

Research Repository

Advanced Search

Comparison of the impact of moisture on methane adsorption and nanoporosity for over mature shales and their kerogens

Li, Wei; Stevens, Lee A.; Uguna, Clement N.; Vane, Christopher H.; Meredith, Will; Tang, Ling; Li, Qianwen; Snape, Colin E.

Comparison of the impact of moisture on methane adsorption and nanoporosity for over mature shales and their kerogens Thumbnail


Authors

Wei Li

LEE STEVENS LEE.STEVENS@NOTTINGHAM.AC.UK
Senior Research Fellow

Christopher H. Vane

Ling Tang

Qianwen Li

COLIN SNAPE COLIN.SNAPE@NOTTINGHAM.AC.UK
Professor of Chemical Technology & Chemical Eng



Abstract

© 2021 Elsevier B.V. Moisture in shales under reservoir conditions adversely affects gas adsorption and nanoporosity and is also likely to impact on the contribution that kerogen makes to the methane adsorption capacity. To investigate these phenomena, two over mature shales from the Wufeng-Longmaxi Formation, south of the Sichuan basin, and their kerogens isolated by demineralisation were investigated dry and at 95% relative humidity (R.H.) by high-pressure methane adsorption, and low-pressure nitrogen (N2) and carbon dioxide (CO2) sorption. The kerogen concentrates account for 68–97% and 50–64% of the methane adsorption capacities for the shales dry and at 95% R.H. respectively. However, the isolated kerogens could adsorb more methane than the organic matter in the shales because their shallower adsorption isotherms indicate large micropores and small mesopores not evident for the shales. Methane adsorption capacities of the kerogens and shales reduced by 46–72% at 95% R.H. This compares with the reductions in surface area (SA) and pore volume of 81% and 48–59%, respectively, for the kerogens and 98–99% for both SA and pore volume of the shales at 95% R.H. Water can block most micropores less than 1.3 nm reducing the micropores volume and blocking the micropore necks connecting the larger pores, and vastly reducing accessible pores for gas transport. The greater proportional losses in SA and pore volume compared to the methane adsorption capacities is probably due to ice forming at −196 °C in the low-pressure N2 analysis. Failure to take moisture into account for free and adsorbed methane overestimates the total gas in place (GIP) by 36–45% for the shales investigated.

Journal Article Type Article
Acceptance Date Feb 1, 2021
Online Publication Date Feb 6, 2021
Publication Date Mar 15, 2021
Deposit Date Feb 19, 2021
Publicly Available Date Feb 7, 2022
Journal International Journal of Coal Geology
Print ISSN 0166-5162
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 237
Article Number 103705
DOI https://doi.org/10.1016/j.coal.2021.103705
Keywords Kerogen, Moisture, Methane adsorption capacity, Nanoporosity.
Public URL https://nottingham-repository.worktribe.com/output/5334763
Publisher URL https://www.sciencedirect.com/science/article/abs/pii/S0166516221000318
Additional Information This article is maintained by: Elsevier; Article Title: Comparison of the impact of moisture on methane adsorption and nanoporosity for over mature shales and their kerogens; Journal Title: International Journal of Coal Geology; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.coal.2021.103705; Content Type: article; Copyright: © 2021 Elsevier B.V. All rights reserved.

Files





You might also like



Downloadable Citations