TN1034 : Modeling of methane gas outflow from coal Seams into drainage boreholes and providing a suitabale boreholes pattern and their characteristics
Thesis > Central Library of Shahrood University > Mining, Petroleum & Geophysics Engineering > MSc > 2021
Authors:
Abstarct: Coal has been used as one of the main sources of energy in the world for centuries. One of the major dangers of underground coal mining is the presence of methane gas, which causes many casualties in the world's mines every year. The presence of this gas in the mines, in addition to creating a dangerous and explosive environment for miners, also increases the cost of ventilation. Accordingly, methane drainage before coal mining can reduce the hazards in these mines. In this dissertation, first, using equations, hypotheses and information obtained from Tabas Coal Mine and using COMSOL software, drainage simulation of C1 laxyer of Parvadeh I Tabas Coal Mine was performed and then Suitable methane boreholes were designed by 3D modeling by COMSOL. baxsed on the simulations, it was observed that the amount of methane emission varies with increasing or decreasing distance from the boreholes. As inferred from the model, the gas outlet pressure from the boreholes was reduced by 10% in the first to third days of drainage. This value varies depending on the porosity of the coal, the number of boreholes and their diameter and depth. Using two boreholes, the pressure in the coal laxyer was reduced by 17%. The pressure drop is greater in models with more than two boreholes due to the increased suction power. When the boreholes are 66 mm in diameter and the model is three-borehole, the methane pressure near the boreholes is reduced by 90% on the 15th day of drainage. The graphs show as the longer the boreholes, the faster and in less time the pressure drop occures. The results were consistent when the results obtained from the new model were compared with the model made for other similar mines.
Keywords:
#Keywords: Gas drainage #methane #Coal gas seams #Three-dimensional modelling #COMSOL Software Keeping place: Central Library of Shahrood University
Visitor:
Visitor: