Optimum Layout of Multiple Tree-type Boreholes in Low-Permeability Coal Seams to Improve Methane Drainage Performance

Estimation of coal seams gas content for evaluating potential use of methane drainage system in Tabas coal mine

Methane gas emission, accumulation, and explosion are the most important risk factors in underground coal mines. Hence, having a knowledge of methane gas emission potential in underground coal mines is of crucial importance in preventing the explosion risk, loss of life, and property, and providing miners' safety. The purpose of this work is to provide the prediction maps for the C1, C2, and B2...

Actions to improve coal seam gas drainage performance

Coal seam gas drainage is affected by many factors which may be generally divided into two groups, geological factors and operational factors. Studies conducted in the Bulli seam found geological factors had a dominant impact on coal seam gas drainage while operational factors had a secondary impact, affecting the amount of optimum gas drainage performance achieved within the limitations impose...

Permeability evolution during progressive deformation of intact coal and implications for instability in underground coal seams

We report measurements of deformation, strength and permeability evolution during triaxial compression of initially intact coals. Permeability is continuously measured by the constant pressure differential method, together with axial and volumetric strains for both water (H2O) and strongly adsorbing carbon dioxide (CO2) gas. Strength and Young’s modulus increase with increasing confining stress...

Efficiency of Technologies of Intensive Methane Recovery from Coal Seams and Mines Proposed for Closing

Research on the Effective Influence Radius of Hydraulic Reaming in Mining Seam

According to the present situations that the construction amount of the gas drainage boreholes in mining seam is large and the gas drainage effect in low permeability coal seams doesn’t yield perfect, the hydraulic reaming technology in mining seam is proposed to increase the gas drainage efficiency. Through the gas flow method, the effective influence radius of hydraulic reaming is determined....