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The Technology Research Of Gas Pre-drainage Through Floor Cross-measure Boreholes Of6Coal Seam In Zhangji Coal Mine

Posted on:2015-09-25Degree:MasterType:Thesis
Country:ChinaCandidate:Y F DouFull Text:PDF
GTID:2181330431491290Subject:Safety engineering
Abstract/Summary:PDF Full Text Request
Coal is basic energy in our country, and coal mine gas disaster has always been a serious threat to the major factors of coal mine safety production and the life safety of the workers. Taking Zhang Ji coal mine of huainan mining group6coal seam as test object, through the combination of theoretical analysis and field tests, Use pressure method to measure the coal seam extraction radius and optimize the borehole layout, verify the gas extraction effect of borehole gas pre-drainage. At the scene of the experiment measured the6coal seam basic parameters of gas, the basic parameters of gas is that the original coal seam gas pressure is0.875MPa and the gas content is3.95m3/t. Observed by one months, we can see the gas drainage radius in seam with pressure released is3.42m. According to the radius of extraction in order to make the extraction of gas in coal seam no blank, calculate out the wear layer drilling reasonable spacing, combined with the actual situation proposed the drainage borehole in reasonable decorate plan is that design the drainage borehole layout mode for:10m×5m grid layout, drainage borehole extraction in scope extends to6coal return mountain outlines15meters; an experiment was conducted about residual gas pressure and content measurement after gas pre-drainage, through this process, the result can be obtianed that residual gas pressure is0.875MPa and residual gas content is1.35m3/t. On the basis of comparion of gas pressure and content before and after drainaging, and comparion of these two physical quantities’s residual with the outburst critical value, can figure out that the wear layer drilling drainage of coal seam gas extraction rate was68.5%, the gas content and the gas pressure are lower than the critical value in the prevention and cure of coal and gas outburst rules that proves the wear layer of drainage gas drilling technology has obtained the good effect of elimination, provide protection for the safe and efficient production.
Keywords/Search Tags:gas pre-drainage, floor cross-measure boreholes, drainage radius, layout optimization
PDF Full Text Request
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