Fractal characteristics of methane migration channels in inclined coal seams

Pengxiang Zhao, Risheng Zhuo, Shugang Li, Chi Min Shu, Yongyong Jia, Haifei Lin, Zechen Chang, Chun Hsing Ho, Bin Laiwang, Peng Xiao

Research output: Contribution to journalArticlepeer-review

Abstract

Methane safety extraction is an effective method for reducing methane concentration in the gob and enhanced coal-bed methane recovery that is widely used in China. Although there is already extensive research on this technique, dip angle coal of seams has unpredictable effects on methane extraction locations, which is an influential factor that has rarely been studied, especially where the seam dip angles are larger. The benefits of this paper include improving methane extraction techniques, exploring the fractal characteristic of channel, and developing the laws governing how channels emerge, especially where coal seam dip angles vary. The results show that with increased coal seam dip angle, the height and width of channels show an increasing trend, along with crack angle. Key parameters of the methane migration channel boundaries in mutant regions of the bed separated under inclined coal mines were also defined. In the laboratory, an effective model was put forward to calculate the evolution characteristics of channels under inclined coal mining using fractal and elliptic paraboloid zone theory (EPZ); the finding was that the height of the A region at 30° was 1.34 and 2.00 times that of 15°, 0°, respectively. Moreover, borehole methane extraction concentration in area B increased to 6.04% in field application. The research results are expected to benefit industry and mine safety staff when arranging the position of high-level boreholes. The findings can enhance safety levels and improve efficiency in inclined coal mining.

Original languageEnglish (US)
Article number120127
JournalEnergy
Volume225
DOIs
StatePublished - Jun 15 2021

Keywords

  • Dip angle of coal seam
  • Fractal characteristic
  • Inclined coal mining
  • Methane migration channel
  • Methane safety extraction

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Building and Construction
  • Modeling and Simulation
  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Energy Engineering and Power Technology
  • Pollution
  • Energy(all)
  • Mechanical Engineering
  • Industrial and Manufacturing Engineering
  • Management, Monitoring, Policy and Law
  • Electrical and Electronic Engineering

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