Mechanism of gas resistance in macroscopic and microscopic fractures during coal water injection and methods for breaking gas resistance

Jian Chen, Yingxin Li, Liwen Guo, Xuehan Yan, Xinda Yang, Yanlei Guo and Jianguo Wu

Energy, 2025, vol. 328, issue C

Abstract: To observe the mechanism by which gas resistance is generated within macroscopic and microscopic coal fractures, this study developed a micro-extraction experimental system for analyzing coal chips, and researched on the mechanism of gas resistance generation within the water injection fractures and the methods for breaking gas resistance. Results showed that micron-scale large gas bubbles migration is easily affected by the vortices of stagnant bubbles, leading to coalescence and detours, which eventually plug fractures. Under the sole influence of wall effects, the migration of micron-scale large gas bubbles are affected by their distance from the wall (S), and the Reynolds number (Re). When S decreases or Re < 100, the bubbles tilt toward the wall. The dimensionless form S∗ of S is negatively correlated with the bubble velocity. Under the competitive effects of wall effects and the gravitational attraction of stagnant bubbles on the opposite wall, when the distance between migrating bubbles and stagnant bubbles (S1) is less than 0.1346 mm, the bubbles tilt toward the wall. Increasing flow velocity is beneficial for breaking gas resistance. The flow velocity and the stagnant bubble aspect ratio exhibit a positive exponential relationship. The critical aspect ratio for breaking gas resistance is 1.4179.

Keywords: Coal water injection; Coal chip; Gas resistance; Macroscopic and microscopic fracture; Stagnant bubble (search for similar items in EconPapers)
Date: 2025
References: Add references at CitEc
Citations:

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0360544225022133
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:328:y:2025:i:c:s0360544225022133

DOI: 10.1016/j.energy.2025.136571

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 ().