Goaf gas source comprehensive judgment and prediction method

Abstract

The invention relates to a goaf gas source comprehensive judgment and prediction method. The method comprises the steps of conducting comparison and analysis on the difference between methane stable carbon-hydrogen isotope, ethane carbon isotope and stable carbon isotope of carbon dioxide in goaf gas and the similar stable isotope in target formation desorption gas, with the combination of concentrations of goaf gushing gas and desorption gas in the coal seam and in the adjacent seam, and through isotope source value calculation, determining goaf gas sources, and forming a set of comprehensive judgment method based on isotope judgment and combined with the gas component analysis. According to the goaf gas source comprehensive judgment and prediction method, gas volume ratio from different end members can be more precisely calculated. By judging and predicting the goaf gas sources, a positive and effective gas extraction technology is formulated, the greenhouse effect due to dissipation of goaf gas to atmosphere is reduced, achievement of gas resource green exploitation and utilization is promoted, and considerable social, economic and environmental benefits are obtained.

Description

technical field [0001] The invention relates to the field of coal mining, in particular to a method for comprehensively judging and predicting gas sources in goafs. Background technique [0002] At present, most of the researches on the goaf have studied the gas concentration distribution, gas flow and gushing law of the goaf by using the theory of seepage mechanics and numerical simulation. In terms of mine gas emission prediction research, the calculation methods of gas emission theory in gobs include the separate source calculation method, the estimation of gob gas emission amount based on the change of return air gas emission before and after the collapse of the old roof, and the drawing method. Wait. [0003] Through the dynamic analysis of gas sources and predictions in goafs at home and abroad, it can be seen that gas sources in goafs are complex and have many influencing factors, and most of the research work that has been carried out is mainly based on gas concentr...

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Problems solved by technology

[0003] Through the dynamic analysis of gas sources and predictions in goafs at home and abroad, it can be seen that gas sources in goafs are complex and have many influencing factors, and most of the research work that has been carried out is mainly based on gas concentration investigations and gas flow law simulations Although we have some empirical understanding of the source of gas, it is mostly based on qualitative knowledge, and the understanding of the source of gas from specific coal seams is not clear, so we need to make a breakthrough in the comprehensive identification technology of gas source

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