The Gas Extraction Next To The Drilling In Water Technology Research Of The Coal Rock

With the increase of mining depth, ground stress, gas content and pressure increasing, the threat of mine gas emission and gas disaster has increased dramatically, gas and coal and gas outburst mines, how to take effective measures to realize safe and efficient mining has become an important task facing the mining workers. Before coal mining drainage is an effective regional technical measures to prevent outstanding in certain conditions, Its claim to the coal seam occurrence condition is low, easy construction, low cost.With the enlargement of the scope of coal mine, the increase of mining depth, increasing gas disasters, due to the effect of coal mining layout, in many areas it is necessary to adopt mine next to the drilling for gas extraction, and assignment of Gubei mining of coal seam roof and floor is rich in water, next to the borehole construction difficulties, the gas extraction result is bad, in consequence, research mine under the condition of given water to the long into the hole, hole drilling technology and drainage technology and hole sealing process, study of the extraction process, key technology; Through the field test is proposed to solve the long borehole extraction gas the technical difficulties, next to long borehole extraction gas extraction and get good effect.This topic research is in the full collection of Gubei coal mine based on a large number of literature, Through a large number of field test and laboratory experiments, master Gubei4layer of coal mine gas based parameter. Come from the Gubei4layer attenuation coefficient of gas flow during drilling in coal mine in0.09248d-1～0.1009d-1range fluctuations, average drilling gas flow attenuation coefficient is0.09742d-1, the permeability coefficient is0.090358654m2/MPa2·d. According to the principle of gas pressure reducing method, through long-term observation pressure hole gas pressure change and different distance through scientific and reasonable measure can be concluded from north mine4layer in continuous extraction from a month can achieve3meter radius of extraction, Under the developed to the boring construction technology has solved the coal seam under the concentrated stress on the borehole collapse, extraction hole sealing leakage and other problems, meet the test area between layers to the long hole under the water under the condition of the gas extraction, raise to drilling under the extraction effect.