Influence Of Coal Adsorption On Gas Seepage

The liquidity law of the gas in the coal is the basic problem of the gas prevention and cure technique fields. Adsorption characteristic is special characteristic which differentiate the coal from other penetrability. Studying adsorption characteristic influence to the law of penetrability has important guiding role to the basic theory study. Such as gas emission, gas drainage (coal seam gas exploitation), coal and gas outburst prevention technology. Through the combination way of experiments, theoretical analysis, numerical simulation, the text studies systematically adsorption characteristic to the law of penetrability of the coal-gas.Export innovative adjustable pressure and temperature-controlled gas permeability. Using self-developed gas-seepage experimental installation, in different pressure conditions, performed coal permeability experiments on different adsorption characteristics of coal sample, different gases adsorption, and different gas adsorption content, studied the influence law of adsorption on coal permeability. The results showed: Calculated the average permeability rate of coal seam by Darcy's law described the whole gas migration dynamic process bring error. By stress, gas pressure, temperature and other factors affecting the average permeability rate is constantly changing. The permeability rate which is the function of time,space and the gas pressure , described by Darcy's law seam gas flows more in line with the actual process. Adsorption has a major impact on the coal permeability. The greater adsorption, the more gas adsorption capacity, and the coal permeability become smaller. And this accord with the locale practice results.In the theoretical studies, the text analyses the influence of adsorption characteristics to three aspects, such as coal-gas energy, porosity, and effective stress, establishes the mathematical model, and carry through numerical simulation calculation on the basis of this model. The result shows that the model is basically up to actual measurements and experiment laws.