Research on confining pressure effect of pore structure of coal-rich in coalbed methane under cyclic impact

Ning Luo; Yunchen Suo; Xueru Fan; Yishuo Yuan; Cheng Zhai; Weifu Sun

Energy Reports (Nov 2022)

Research on confining pressure effect of pore structure of coal-rich in coalbed methane under cyclic impact

Ning Luo,
Yunchen Suo,
Xueru Fan,
Yishuo Yuan,
Cheng Zhai,
Weifu Sun

Affiliations

Ning Luo: State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou 221116, China; State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China; School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, China; Corresponding author at: State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou 221116, China.
Yunchen Suo: State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou 221116, China; School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, China
Xueru Fan: State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou 221116, China; School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, China
Yishuo Yuan: State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou 221116, China; School of Mechanics and Civil Engineering, China University of Mining and Technology, Xuzhou 221116, China
Cheng Zhai: School of Safety Engineering, China University of Mining and Technology, Xuzhou 221116, China; Corresponding authors.
Weifu Sun: State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China; Corresponding authors.

Journal volume & issue: Vol. 8
pp. 7336 – 7348

Abstract

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Coal seam penetration modification is the primary technical problem facing the efficient development of coalbed methane and coal mine methane control. To study the effect of cyclic impact load on the permeability of coal rock under the confining pressure, the dynamic mechanical properties and the pore evolution of coal were conducted by using the separated Hopkinson pressure bar (SHPB) and the low-field nuclear magnetic resonance (NMR) technique. The results showed that the dynamic compressive strength existed as a turning point at a critical confining pressure of 6 MPa and the spectrum area growth rate of adsorption pores was negatively correlated with that of seepage pores. As the confining pressure increased, the pattern of the effective porosity growth rate of the coal was positively correlated with the peak compressive strength, meanwhile, the permeability growth rate of the coal showed an exponential growth trend. The evolution pattern of the permeability under the coupled action of the confining pressure and impact pressure was obtained. In addition, based on the U-shaped distribution of permeability growth rate and effective porosity growth rate with the impact pressure, an exponential relationship between them was derived. The related research results could provide important theoretical support for coalbed methane exploitation.

Published in Energy Reports

ISSN: 2352-4847 (Online)
Publisher: Elsevier
Country of publisher: United Kingdom
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering
Website: http://www.journals.elsevier.com/energy-reports/

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