Pre-extraction Coal Seam Gas Drilling Of Numerical Simulation And Application

Gas disasters that affect the major coal mine production safety factor, and pre-pumping coal seam gas is a solution of such accidents the most fundamental and most effective measures. This fluid in porous media according to the conservation of mass, to directional drilling of coal body around the level of long gas flow field as the research object, the establishment of the boreholes coal gas seepage model and analysis of its numerical solution. Application of elastic-plastic mechanics and mining rock mechanics, drilling around the coal derived mathematical equation of the scope of destruction, get bored around the damage radius of coal relief. Numerical simulation by FLUENT software to analyze the different extraction time, extraction negative pressure, coal permeability, gas pressure, drill diameter drainage hole under the conditions of the radius and volume of gas extraction, are of various factors on drill Pre-pumping coal seam gas were investigated.According to Shenhua Ningxia Coal Industry Group Baijigou the actual conditions of coal mines, coal mine gas deposit of the law, and Working Face Gas Emissions Rules, applications are sub-source prediction of gas emission face. Reasonable based on analysis of coal seam gas drilling pumping of the main factors expected to establish a reasonable period of pre-pumping model, combined with the principle of directional horizontal borehole arrangement, be reasonably expected that the coal seam gas drainage period. Practice through on-site analysis, directional horizontal borehole effects and characteristics of CMM, to prove that lowering the working face of the gas emission, to ensure safety in coal mines Baijigou important, and that the computer simulation software FLUENT mine gas extraction process parameters have important theoretical reference value.