The dynamic evolution model and experimental study of gas permeability under multiple factors

Abstract

This paper aims to ascertain the relationship between permeability and temperature of gasfilled coal. For this purpose, the author probed into various influencing factors of permeability, and constructed a permeability evolution model involving temperature, effective stress, gas pressure and humidity. Then, the proposed model was improved through an experimental research using thermal-fluid-solid coupling triaxial seepage test device. It is found that the theoretical results of the model agree well with the experimental data, indicating that the improved model is an ideal tool for predicting the gas flow pattern. The research results lay a solid basis for enhancing gas drainage efficiency and preventing gas outburst.

Variations in Adsorption of Two Step Solvent Extracted Vitrain and Their Coal Crystallites Response

“…Published studies show that the reaction of the crack of oxygen-containing functional group is main form at the early stage. With coal rank increasing, the reaction turns to aromatics branched chain cracking, then to bituminous larger molecules crack during the stage of the coal-generated hydrocarbon process [19][20][21][22][23].…”

Microcrack evolution and permeability enhancement due to thermal shocks in coal

“…It was found that the change of coal permeability with temperature variation primarily depended on the interaction of thermal and effective stresses, and was related to coal deformation. In addition, some permeability formulas combined with temperature and effective stress were successfully proposed to predict coal permeability under different conditions [30][31][32]. Heat injections increased coal permeability because in coal, sharp temperature change possibly leads to uneven thermal deformation and microcrack generation [33][34][35][36].…”