Investigation of CH4/CO2 competitive adsorption-desorption mechanisms for enhanced shale gas production and carbon sequestration using nuclear magnetic resonance

Guangzhao Zhou, Xianggang Duan, Jin Chang, Yu Bo and Yuhan Huang

Energy, 2023, vol. 278, issue PB

Abstract: Understanding the competitive adsorption-desorption mechanisms in shale is of fundamental significance for enhancing CH4 recovery and CO2 sequestration. This study adopted nuclear magnetic resonance to reveal the influence of CO2 on adsorption-desorption behaviors of CH4 in plug-sized samples. Three distinctive peaks were observed in the transverse relaxation time (T2) spectrum of a CH4-saturated sample, which indicated the adsorbed CH4 (0.1 ms < T2 < 1 ms), free state CH4 in pores (2 ms < T2 < 30 ms) and free state CH4 in fractures (100 ms < T2 < 1000 ms). When CH4 reached adsorption equilibration under 20 MPa, the total T2 signals of adsorbed CH4, free state CH4 in pores and free state CH4 in fractures were 565.3, 591.5 and 306.6 p. u., respectively. Subsequently, CO2 was pumped into the CH4-saturated sample under 22 MPa. When CO2–CH4 completed the competitive adsorption process, T2 signals decreased from 565.3 to 396.6 p. u. for adsorbed CH4, increased from 591.5 to 707.3 p. u. for free state CH4 in pores, and increased from 306.6 to 359.5 p. u. for free state CH4 in fractures. Afterwards, the desorption of shale sample began. CH4 concentration decreased from 79% to 55% while CO2 concentration increased from 21% to 45%. Finally, the total desorption rate of adsorbed CH4 (65%) was much higher than that without introducing CO2 (25%–40%).

Keywords: Adsorption; Desorption; Competitive mechanism; Shale gas recovery; CO2 sequestration (search for similar items in EconPapers)
Date: 2023
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (2)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0360544223013580
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:energy:v:278:y:2023:i:pb:s0360544223013580

DOI: 10.1016/j.energy.2023.127964

Access Statistics for this article

Energy is currently edited by Henrik Lund and Mark J. Kaiser

More articles in Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().